Depends of the CNC you're needing to carve, the aluminum sourcing, how clean you want your mold to be (with/without much layer lines for example if you're not using 5 axis). Also companies have to pay time spent to 3d design and test the molds prototypes, so it varies a lot if by "DIY" you means hobbyist or small lab.
It can be done without a CNC. You can make a positive of the item (say, on a 3d printer) and then create a mold from high-temperature silicone. It does benefit a lot from being placed in a rigid shell (e.g. a metal blank) and it does have some wobble in fine details that needs to be taken into account. That said, it's not easy; it took The Crafsman quite a few tries to get a working mold using this technique, but he has successfully done injection mold runs this way. But the cost of CNCs are dropping extremely rapidly, too, so this is not the price savings it once was when molds were several thousand dollars...
@@TheOfficialOriginalChad It basically makes what the flies perceive as a solid wall so they don't go in. Plus they can't move them by themsleves so they can't go through.
@@TheOfficialOriginalChadIt’s like a screen door that they have in America. It’s so you can open your door when it is very hot without flies coming into the house.
Why did you print the comb in that orientation? Just off the top of my head, that would be the absolute worst orientation for it - the forces are going to be perpendicular to the layer lines and you'll break teeth, AND it would print much slower because you have to wait for the small layers to cool, AND you'd have a ton of stringing (potentially). I used to be in industrial plastics - injection molding, blow molding, crown molding, the works. I'd say the biggest benefit of 3D printing is consistency and ease of use. We'd have machines that would be cranking out parts without issue all night, then someone 3 buildings away would sneeze and we'd spend the rest of the shift trying to get the parts going again. You'll sometimes get prints that don't want to cooperate, but I've never had the issues with even my cheap, ancient 3D printer that I had with the big injection molding machines. But ultimately, you're right. Injection molding does one thing, it does it very well and very quickly. 3D printing does a nearly unlimited number of things, very slowly and with a rough finish. For now... I think the story will be very different in 20 years.
The thing you need to account for is the cost of machines. With basic optimizations, you can get the throughput of a 3d printer factory to be equivalent to an injection molding machine at the same cost. And that can be done today. Only once you are talking the absolutely massive machines that can spit out hundreds of thousands of parts per day does that end up favoring injection molding again, and only because you can micro optimize the material use and save enough money for it to make sense. Lego bricks for example would be stupid to print as you would need to change their size so they are larger in order to be strong enough. Duplo bricks would make sense if they were printed.
3d printing excels where you want to be able to customize or personalize items. Not for mass scale manufacturing generally. So not a great comparison. But a fair point.
Actually for the cost of one employee operating 3 mold machines, I can purchase 100 bambu A1 minis, pumping out 5 combs an hour each. That is 12000 combs a day max, far far far greater volume than what the small injection modling can do.
@elitewolverine if you can respool and clean and whatnot within 1-1 minute per printereafter every print and you can sequence the prints so you are continously scrape the beds and whatnot then you loop around every 100 mins... so max 7 loops a day. That is only 3500 combs my dude
@@elitewolverine You comb your hair with that 3d comb for year and I'll use the injection molded one. I guarantee you at the end of the year, yours will not have held up as well as the injection molded one.
You guys should collab with Slant3D on a 'challenge' to refine the scope of when to use 3d print farms vs. when to invest in injection moulding. I agree with your conclusions that each has their place. It'd be very entertaining to see two very passionate sides of the argument go head to head, though ... sorta like a heavy weight boxing match for plastic production!
3D printing and injection moulding have their use cases and I love the fact that you gents went through the pros and cons between the two technologies and processes. Use a 3D printer to help prototype a design with the intention of using injection moulding later for larger scale manufacturing. I'd imagine the aluminum injection moulds costs quite a bit of money and time to fabricate so using a 3D printer to iterate through your product design makes the most sense, minimizing the cost and time spent creating the moulds for injection moulding.
FDM and injection molding even compliment each other. I've used the DIY recycling techniques from this channel's videos to recycle my own 3d printing waste into useable parts. The panini press melting technique works great with supports/failed prints/printer poop. There are other "recycle your 3d prints" videos on youtube, but most of them don't get the quality marbling demonstrated in Brothers Make videos (sorting your plastic and careful folding makes for a much more visually striking final product)
3D printing shines with custom tooling. You could make a simple pneumatic press with 3D printed parts for taking those beads off of the sprues all at once
Don't forget manual labor when calculating the price of injection molding, 3D printing is mostly automated leaving you free to do other things. Injection molding requires you to be there the entire time.
@@OpalSea And they answer it wrong. They said "you have to maintain the printers" as if that takes nearly the same amount of time as operating the injectors. It absolutely does not. Source: we have shelves full of prusa XLs that I work on at my workplace, and I also work with a guy who runs a bambu farm. You only get similar labor cost with unreliable printers. The prusa mark 4 used in the example might actually be _the_ most reliable printer that you can buy below enterprise grade.
@@Mindbulletz I've worked in injection molding shops with fully automated equipment that just requires someone check on it to swap the output bin when it's full, and refill the input hopper every few hours. Thousands upon thousands of perfectly clear medical-grade parts came out of that machine every shift. The real story, which they talk about in the conclusion, is that for any given part, there's a volume of output where it makes sense to switch from FDM to injection.
moulds are expensive add another 5k for a cnc machine and probably £30-50 for material then your getting closer to equality 3d printing will always be faster for one offs or prototypes injection moulding is always cheaper for mass production
Mold making is a specialty in its own right. Also don’t forget the cost of work holding, tool holding and the bits, you can sink a lot of money in those. The cost of the shop space it takes shouldn’t be ignored either.
Molds can be made very inexpensively as in this case where they have straight pull parts with split line molds. If you design the mold and just have it cut at a local machine shop out of 6061 or 7075 aluminum, you're only paying for machine time so the cost is quite cheap. I've done molds like this for several customers fishing lures, watch pieces, USB over molding, etc and they usually run a couple hundred dollars. You didn't have to buy and own all the equipment to do this.
Injection molding only has two things going for it, first is strength for small parts (3d prints are stronger for large parts) and cranking out excessive amounts of parts in short order. But you rarely get orders like that so it is almost always better to just maintain a stock.
@@SirSpence99 I don't know where your experience in injection molding comes from but rarely did we receive orders for less than several thousand pieces. In 25 years of being in injection molding I can count on one hand the amount of times molds were changed so much that they had to be redesigned or remade. Most were minor changes that took a day or two and we were back making parts. I have aluminum molds with 100's of thousands of parts made on them so expensive hardened steel molds are not required. Large parts for 3D printing aren't even comparable in quality to Injection Molded pieces. From surface finish to strength of parts. Where 3D Printing works in plastics is for prototyping and very short runs but once again there is NO COMPARISON in the quality and strength of a molded part.
If you want to make massive abounts of the same item then injection molding is better. If you are prototyping, making complex parts, short runs or a job shop, 3d printing is better. Making 3d filament is also a valid use to recycle plastic. For the average person, they will get WAY more use out of a 3d printer than injection molding. For the small boutique recyclers trying to make the most product, the injection molding will make a lot of sence.
And when you say massive amounts, that starting point is at about 100k pieces. And even then, 3d printing is going to be competitive. This example they have is the ideal setup for injection molding and the worst for 3d printing and they didn't even pretend to make it fair. Ask them how much they spent on machines...
@@SirSpence99 100k pieces?!! You do know you can get far less than that right? In the case of the combs you could get 200 pieces and the mold made quite inexpensively plus you could get reorders fairly quickly or even delivered seamlessly if you have known quantities spaced throughout the year or lifetime of the product. PLEASE SPEAK TO SOMETHING YOU KNOW ABOUT!
@@yatyas72 Generally it helps when you want to disagree with someone that you address what they said instead of something you made up. Why don't you think for at least a second this time and not assume I am an idiot and might have a point. Assuming you aren't an idiot, you should be able to at least get an inkling for why your comment is irrelevant.
If 3d printers could make parts cheaper and faster, then industry would have stopped plastic injection long time ago. It can makes part at home, which is already impressive.
Shoe companies now have 3d printers, for designs that are impossible with injection moulding. It doesn't take much complexity to eliminate injection moulding as an option. I really like the option of both though, different use cases for sure, and recycling/ reusing has to be better then land fill.
@@LucianoFoxtrot it is pretty new to the shoe industry. Printers and materials have evolved to the stage that it is now viable. These are not generally the hobby level machines or materials.
You should make a collab with Slant3D. You could design a functional part for injection molding while Gabe could design a part for the same function for FDM mass production and finally you could do the math and cross-check the forecasted costs. That would be something really interesting to watch...
The Crafsman has made some discoveries that could drive the cost of injection molds down significantly, especially for small batches. He got a couple blank molds made, and then slots high-temperature silicone molds (made from positives that are resin-printed) into those. So he can make injection molds at home. They won't last as long as CNC'd molds, but they can be iterated on for much, much cheaper.
@@Biru_to Yeah, they're a little floppy, so the extra support keeps them in place and helps resist the pressure from the injection process. He's had success with just backing with cardboard, but prefers the metal blanks for rigidity and repeatability.
@@oasntet Thanks for answering my question! Probably is worth it over something simple/cheap like cardboard / mdf when you do a lot of molding like he does. 👍
Great video, injection moulding can make usable things from recycled plastic, and 3D printers create prototype problem-solving solutions. In my opinion, they are difficult to compare, but you did a good job demonstrating it. Both have their place in a good markerspace ♻️
It takes 200 hrs (8 to 9 days) to print 9000 beads on my single Voron 3D printer (costs $600 to build) - this is actual print slicing calculation. Estimated with beads having an 8mm diameter and a 1.6mm hole. There is zero plastic waste, and total labour cost is about 45 minutes - 5 minutes to clean the print plate once daily for 9 times.
I'm not doubting that both have their pros and cons but I don't think you really give a fair comparison. 1. Nobody would print a comb standing on end the way you had it. Having it lay down would make it faster & stronger. 2. 100% infill does not add strength. See CNC Kitchens testing. 3. Print farms can be mostly unmanned. With automation the printers can be mounted at a 45° or greater angle. When the print finishes, it cools & releases from the bed, falling into a catch bin. The print head swees the bed to ensure the part fell into the bin & then continues to print the next part. This continues until it is out of filament. You can also use 5kg spools to do more without human labor. If injection is your thing, then great. You do you, but you did put up a rather flimsy strawman.
I have 3 3d printers (2 fdm, 1 resin) and run a small 3d printing service and I adore 3d printing, but 100% they're just not practical or appropriate for a lot of tasks. I'd never consider printing a comb because regardless of resin or filament or infill used it just won't have the structural integrity to be useful, especially for the long term compared to an injection moulded one, and especially compared to one which can be endlessly recycled.
I think the orientation used for the comb printing is pretty "wrong". The tines should be printed horizontally to give them strength. A bit a cleanup is needed on the bottom side to remove support material, though. That said, I haven't actually tried printing a comb.
13:59 Did you really want to print this comb in this orientation...? I think if you set it lying down you could get down to 20 minutes of printing or even less.
That mini Injection moulding machine is awesome! would love one of them!..... With the Injection moulding the mould is the slow bit right, you have to make the mould or buy it....
Yeah that wasn't included in their time factor. If it takes 3-6 weeks to get the mold that's a couple weeks the 3d printer has to print. I agree both have their place but I think the run volumes are higher than 1 off and are closer to 1000-10000
Don't forget the automatic open-close cycle of a typical cnc injection mold machine. What's being shown here is a job shop/hobbies injection mold process. Not one meant for production volumes.
You guys actually inspired some of my work in molding 3D printed waste into parts for my products. So best of both worlds from this video. Keep up the good work guys!
you should make some kind of punch/cleave that fits the exact shape of the beads after taking them out of the mould, so all you'd have to do to get off the ring that holds them and the excess is push down on it with a lever or something similar
I say this every time I see someone review a product that was made using a 3D printer: 3D printers are great for prototyping and iterating on an initial design, but should not be used for a finished product. The layer lines look awful and injection molded parts are just higher quality. If I'm spending my hard earned money on a product, I want it to look and feel nice. You just can't do that with a 3D printer without lots of post processing work.
This isnt even a quantity vs quantity problem, injection molding makes solid seamless parts that have a very good quality hand-feel, 3D printing just doesn't hold up to that or the structural strength of a 1-shot part. 3D printing is a compromise on all these, in order to do it at home for cheap. On the other hand, we have things like 'fuzzy skin' to help hide layers now, textured build plates. And the ability to print hollow or dense selectively.
If you print the comb laying down, I can safely say the strength of that comb on a 3d print is the same strength or super close to it, using similar materials.
You should try holding a 3d printed object that was printed with said "fuzzy skin". It has a much, much nicer feel than any injection molded part. Night and day difference. And yes, it does completely get rid of seams and layers.
@@SirSpence99 I mentioned fuzzy skin at the end of my prior comment. It really depends on what the part is. I kinda think the majority of beads are desired to be smooth and not fuzzy textured though, but it probably has its uses there as well.
I'm currently in the process of making molds for glasses frames. I used my 3d printer to print the items and now I'm about to create the molds using the 3d printed frames so I can make Epoxy resin final frames. I would love the equipment to do injection molds in the future it just looks really fun to me.
Hi Brothers make! I've been a subscriber for ages. I've been working on a machine for the past 3 years that anyone with a small shed and limited tools can make (for very low cost out of salvaged parts). I'm working on making fully recycled 3d printer filament from common house hold plastic. I've also seen that some people have been adding pellet extruders on their printers to avoid filament all together (as pellets would be wayyy easier to make). Love your vids, keep it up (:
I also think a good answer to the question is: this is what you like doing. If you enjoy making this way and like the finished result, keep doing what you’re doing
LOVE THE VIDEOS!! Your guys injections are so clean. We are struggling with flashing especially with the beads mould. We have tightened the mould as much as we dare but it still happens. thanks Mike
*LOVE THE COMB MIC HOLDER* 😂❤ I love your way better. The point is *recycling* so this is the best way to produce them for y’all. Love your channel and what you stand for! Keep it up! Hugz, Tree
Okay, I think the main difference between these is that injection moulding is a specialised process, whereas 3D printing is a jack-of-all-trades (master of none). If I wanted to create a new item, like a new keychain charm, and I owned a 3D printer, I could design it in CAD/Blender have it by End of day. Whereas for injection moulding you need to machine the mould before you can start production, and you need to mass produce it to make it worth the cost of producing the mould.
It's also really important to think of failure modes. Delamination can be gradual and also prone to material detachment, maybe even dangerous for lungs when fillers are used. Always think of how things will fail if you are selling them.
I've worked in injection molding for 25 yrs. I bought my 1st 3D printer 3 weeks ago. Injection Molding is far superior but 3D printing allows me to make parts, tools, toys, etc. that are unique and useful for me in my home workshop. If I was a maker selling product made of plastic, I would go with IMMs.
I have a lot to ask . Where do you get those molds from? How do you give the melted plastic a particular colour? And where did you get the machine that injects the plastic in to the mold ?
3d printing in all of its forms is for prototypes, oneoffs, and low volume batches. MJF and or SLS is probably what would lend itself most easily to your application, and might even be relatively cost competitive for your smaller parts like those beads, but is definitely far from recycled lol. Something you guys might like though is making resin printed injection mold tooling for second stage prototyping and low volume batches for limited editions. So that kind of workflow might look like this: first stage prototypes on desktop FDM printer, second stage prototype from an MJF machine, third stage prototype from resin printed injection mold tooling. FDM prototypes are virtually free so you can make as many as you need to get the look and feel you're after. MJF is relatively inexpensive, and the mechanical properties are going to be very close to what you're injection molding, so you'll get a really good idea how the actual article would function in real world use, so you could use those for destructive testing and simulating wear. There are even flexibles that closely mimic rubber. Then your resin printed mold tooling will test the final dimensions, draft angles, venting, ejection pin locations, etc. If you don't have any issues with the resin tooling then you can be a lot more confident in investing in CNC tooling. Resin tooling is also really good for injection molded silicone. Since there's no heat involved, and the silicone is so soft, those can actually last a long time. Like a tool you print with a 100 dollar bottle of resin might last as long as the iteration of the part it's making and save you thousands.
You made some good points, but a more fair comparison would be: to use not a ready made machine like prusa or bambu, which are not used by big proffessional farms (except for prusa obviously), but diy machines that are cheap, replicatable and easy to repair. A good diy option could cost up to 400 EUR for a bare minimum machine printing in pla or petg. And you would not need it to print fast. Additionally, throw a custom gcode in the mix for releasing parts, so as soon the print is finished, the printer yanks the part in a front tray as to eliminate human interaction to release prints. Then the print sequence would start again until you have the desired amount of prints. Second, that would also mean your 3d files must be made in a way as to allow easy release of parts by the printhead. That would mean printing 1 bead at a time, but continuously for three days - no supports, no brim. You correctly mentioned that 3d printing allows you to make things that cannot be possible with other means of manufacturing. And this is a bonus many do not use i.e. everyone tries to print parts that are hard to print but easy to injection mold thus many use supports, are flimsy and just bad. A combination of those two points would reduce the cost of the print farm substancially and eliminate any post work. Now, that would still give you a subpar result comparing to a molded bead and less color variation options, but it would definetily lower the price of the print farm. However, with 3d printing you can also add various textures on the fly. Grainy, wavy etc. For injection molded parts you would need a new mold and afaik molds are a bit limited in terms of textures unless you shill a lot of money for it to be made on specialized cnc machines. I may be wrong on this one. Additionally , it would be fair to assume that a print farm would need more space to operate. So that is an expense, especially if you need to heat the premises. That should also be thrown in the mix. You cant squeeze many printers in a small workshop. On the other hand, a big space could also mean that a conpany could invest in a filament maker and recycle filaments in the house. And lets be real , 20 pounds per filament roll is a retail price. For a business, you could easily go dirt cheap if buying in bulk if we are talking about 1 color, especially when you buy 3kg rolls. I mean, i buy my filament in single color pla for 10 euros if i buy 10 rolls or smth. A big business can do lower, say 6-8 eur.
That’s a really cool video and I think the one thing you missed is that aesthetically the moulded ones look and probably feel way better too. On saying that I have another user for the beads I printed my own and use them on the drawstring in sweat shorts as I find every time they go in the wash they end up pulled into the waistband. Keep doing your thing boys as always super proud of you ❤️
Figure eight knits are great for holding ghings from slipping through a hole, they have more bulk than standard overhand/granny knots. The curtain turned out great!
Good video. I have been in 3D printing for 5 years and agree with your results. I rarely print over 5 or 10 copies of something. This is my hobby and I enjoy testing different designs, so for me this is the way to go. I can see a design and be running it in 5 or 10 minutes.
As someone who has actual buckets of 3D printing waste I've been accumulating since 2016, I'm always looking for ways to both optimize cost and optimize material usage in a way that makes sense. This channel has always been insanely helpful for figuring out what to do with all of it. Anyone saying 3D printing is better is clearly just misinformed about strengths and weaknesses of various fabrication techniques.
Actually there are ceramic filled resins intended to print molds for low number batches (like a few hundreds of injected parts). With a price about 250€/liter this might be an alternative to aluminium molds if you want just a few hundreds of pieces. Still you get all the advantages of injection molding. On the other hand prototyping for injection molding is not always easy to do. The object has to be able to be released without much efford. Complex geometrys are not easy to do or maybe even impossible with injection molding. However, if the geometry of the object allows injection molding and you need a bigger number of the same part, injection molding is the way to go. It is not 3d printing or injection molding. Always use the method best for the special project you want to do. And also consider a CNC mil and searching for an industrial mass produced product you can simply take for a start and modify it with some milling... Having all 3 technologys available gives you much more power to do everything you want. It was quite nice to see the prices for small injection molding machines have come down quite a lot. It´s in the price range for hobbyists now. Still, while of course an air-compressor is the professional way to do it: Would it be possible to use a long lever instead to press the molded plastic in? For a hobbyist at home an air-compressor might cause problems with neighbours...
Bring them all together ;) You can start collecting aluminum cans too and sand cast your own injection molds… using a 3d printer to make the model for the sand casting… then injection for mass production
You could speed up the 3D print quite a lot by printing it flat on the bed, 0% infill, and enough walls to fill in the difference. Also, comes don't need fine detail, so you could use a 0.6 or 0.8 nozzle instead of the standard 0.4. Still won't approach the injection molding speeds, but will be a lot faster for prototyping.
There are a lot of items you could never make with injection molding that you can 3D print. Plus there are industrial SLA printers that are now matching injection speed and cost.
I work in plastic injection molding actually and yes it is great for making alot of the same part quickly, and efficiently but being able to make multiple things in a small space is also great maybe time consuming and there are ways to recycle waste
When doing mass production, injection moulding is definitely the solution. If you won’t be doing mass quantities, there’s no way to justify the prohibitively expensive mould. Because of this fact, determining which is better is a little like trying to decide if apples are better than oranges. Each has specific benefits the other cannot match. Now, if you can find a way to 3D print a mould to use in injection moulding, you’ll really have something worth something.
Adapting @ShaketheFuture's "Print Wave Metal Casting" technique, where he 3D prints a negative of a mold with 0% infill and then converts it into a metal-casting mold, seems like a way to marry your 3D printer and injection molding machine into a combo system with most of the flexibility of a 3D printer and the scale production of injection molding. I would love to see you guys try and experiment with DIY poured injection molds using 3D printed framing. IF it can be done and can produce even passable-quality parts in quantities of 50 or so before needing to retire the mold, you will have seriously changed the game in small-run production.
Brothers, fly curtains is a clever use of recycled plastic! Congratulations! I wonder if there is a market for beaded window curtains. The idea is that they would function as sheer curtains, letting in a bit of light.
My biggest question is, where do you get your moulds from? How expensive is it? Without the moulds, the whole thing keeps me from doing it. Without the moulds, I have the impression that you have to do a lot of manual work afterwards, which I don't have most of the equipment for.
HOWEVER you doing the work or letting the printer do the work, while you do other work, makes it a lot of difference and is key here! Besides that there is a big cost to making the molds, something you don't have to worry about with 3d printing. And you can make way more products if you print stacked, and since you don't work day and night, well your printer will just keep going!
BRAVO!! First time to your channel. I've done injection molding for 25 years and have come to the same conclusion. I'm sure someone had already beat me to it but Slant3d really pushes the 3d print farm but in scale and quality you cannot even compare the two. Great job! You have a new subscriber. BTW- I do love my 3d printers but use them mainly for custom and one offs
I noticed in you example of 3D printing your comb, you had in set vertically. It would print much faster laid flat, plus the teeth would be stronger. Also, did you setup multiple combs per print? Obviously injection molding is optimal for the combs; better strength, and faster overall, but I don't think you gave 3D printing it's absolute best potential.
Probably one of the easiest plastics to recycle is PET, because it can be recycled over and over again. Whereas PLA kind of breaks down if you try to recycle it multiple times.
Combo idea. 3d print your mold. Then make a box that can hold the mold for the injection mold. Then use clay or porcelain to clone the plastic mold and the set into the injection box.
3D printing is good for making intricate designs, you basically only need a digital modelling /sculpting app on your computer. BUT extruding machines are the way to go, if you want to mass produce an object. I guess a 3D printer could be used to make a prototype for a mold, which in turn will be used in the extrusion process.
A UV bug trap will solve the fly issue fast. Bug zappers can cause insect body parts to be strewn across a wide area as their bodies explode in the zapper. Another way to keep them out is to use a high speed blower placed at the top of the doorway. This will create an air curtain they can get through. Effective against flying and many crawling bugs.
Yeah, each have their use cases and in most cases they're complementary. Iterative prototyping on the 3D printer, mass production on the injection moulds, if you so wish. Sometimes a 3D print is more than good enough for commercial use, even as functional parts.
If doing iterative design using a 3D printer, you have to keep in mind injection molding limitations, because there are a lot of forms that can't be injection molded, but can be 3D printed. So it requires someone with experience in both methods.
I think this is a great video, I would say you have missed out a way of batching on the 3D printer. You have a much larger print area on a 3D printer. You could print across the whole bed of the printer and then with very small infill between layers print another layer of 3D prints as the printers can print in 3D where as the injection mold is set in one axis. There is the other issue that a awful lot of waste material is created for each mold due to the plastic channels. This is also created in part on the 3D printer but can be dramatically reduced compared to the mold, in the case of the beads. Still a great video and an area of work I had not realised that had become so affordable to enter
Cool video. I didn't know injection molding was as accessible as you're saying it is. If I ever make a hit design and need to make lots of something it's good to know
the machine should suit the product and the production environment. For example the inexpensive injection mold machine can have more material throughput but it requires manual operation. The 3d printer can melt and deposit material slower, but it's automated. The comb could have been 3d printed on it's side, tweaked for 3d printing so that many of them would fit on the build plate, and then printed while you sleep or do something else productive. You couldn't run the injection mould machine while you sleep. When it comes to cost, a 3d printer can work for a lot cheaper than a human per hour.
Inject molding produces better part with longer preparation time and high upfront cost, while 3D print just straight goes from 3D modeling to actual product in a few hours but the quality won't match inject mold. In your case, 3D print is click and go and wait while you consistently manually inject moding.
Touched on it a bit at the end, but IMO the molds would be the biggest point if you are comparing the two methods. You can 3D print anything using the same machine, but you have to buy a new mold for each unique design. And I imagine prototyping designs would be a pain. But I’m here for the sustainability and injection molding of recycled materials is the way to go
I teach Materials Engineering at my local University. Our department is fortunate to have one of the top polymers researchers in the nation. This semester we gave the students a lab assignment in which we tensile tested hundreds of 3D printed dogbone specimens. Each samples feed rate, head temp, bed temp, and print location was carefully recorded, and they then analyzed the results for changes in the stress-strain curve as each of the parameters above was varied. At the molecular level, polymers are made up of long chains of molecules, like a bunch of snakes in a pile. Add energy to them and the snakes start to slither past each other. In a filament print, each layer cools before the next layer is put down. The snakes in the bottom layer are frozen, and the new layer's snakes can't intertwine with them. The layers don't truly weld. All the material for an injection molded part is introduced in a fluid state at one time, and the snakes can knot up however they want. We predicted that the lack of true welding between layers would significantly decrease the strength of the part produced. We used a data set taken from an injection molded set of dogbones as a control. The results were interesting. Across the board, regardless of parameter settings, the 3d printed parts were significantly weaker than the injection molded samples. Our printer featured an enclosed print bed, which allowed us to assume convection heat transfer was negligible. Despite this, the data showed wildly different tensile strengths and ultimate strengths based on the position on the bed it was printed as well. The difference between the left and right sides was a nearly 20 MPa jump. We printed with PLA, which at it's high end is only about 57KPa. More than a third of the strength was lost compared to the Injection Molded samples. For any real design purpose other than a prototype or protype, injection molded polymers will stomp all over a 3D print. However, there are some other uses for 3D printing that have proven to be fantastic. For example, a few years ago our students built a 3D printer that prints solid rocket propellants. The thrust pattern of a rocket can be controlled by altering the shape of the void at the center of the propellant. 3D printing makes it easy to adjust the thrust patterns. A current group of students is now looking to adapt the propellant printer design to work with mining explosives to produce precisely shaped charges. I'm taking that one home if they can get it to work. I'm not picking sides in a YT comment thread, just thought people here would appreciate what we discovered.
Aren't the people saying 3D printers are better completely missing the point? Have they just watched about 3 minutes of your content? It makes no sense! For me, as a model maker, a 3D printer is perfect as I can print out XYZ for a project whenever I need it, with the added bonus that I can use the waste plastic on scratch-builds! You've no idea the stuff I've got stored up in boxes and bags just waiting to be used. I've trained my Mum really well and she'll now ask me if I can use something before committing it to the recycling bin! "Why yes Mother, that old thingy will make an excellent rocket ship engine, I shall put it the metric ton of other crap I have!" 🤣 I've been meaning to leave a comment for a while actually, just saying how nice it wad to meet you two at Makers Central in May! My Mum was incredibly impressed by the glasses and just your general commitment to help keep plastic waste to a minimum. I know you were very busy, but I appreciate the time you took to talk to us, so thanks for that! It'd be amazing if you could be on stage next year. I'm sure many people would be interested in hearing all about what you do and how you do it. Maybe have a word with Nick Zammeti on the How To app? Anyway, just wanted to say that. ☺ And yes, it was Mathew Kelly! Absolute legend! Used to watch him on kids TV back in the 80's. That dates me! Take it easy guys!
anything that falls into the category of 'crap that blows in the wind' things like syringes, plastic bags, beads, and whatnot are better off molded for sure, 3d printing can't compete at such immense volumes. For beads in particular though something that doesn't require post processing is probably better, maybe some kind of weird multi step hot forming/extrusion setup would work? I'm not sure.
I love this video. You nailed it when you said that they're both good for specific things. Also did you know that you CAN recycle filament scrap? Ive been doing it recently because of your videos!
You forgot to add the 3d printing time, the shredding time, and the sifting and sorting time to get the plastic to use in the injection molding machine.
A fair comparison would be to run the printer while you wait for the mould to be machined ;-) Or modify the product slightly so you need a different mould, then wait some weeks for them...
3D Printers can print almost any random 3d object from scratch. With no additional cost and hardware... Injection mold can replicate what's carved in the mold an unlimited amount of time, very fast. But you need do carve the mold, which normally is a third-party service that is expensive and takes time do be made.
I love my 3d printer, but I will admit it's not always the tool for the job. Especially at scale. (Though spherical beads and printing combs vertically are terrible use cases due to print stability) There is a local company near me that makes filament including the cheapest recycled filament I've seen and it's good quality; never had a single clog with it. A lot of people say that Prusa should move to more injection molded parts to drive cost down, but whilst it might lower cost a little, for them 3d printing their parts has the added benefit of QC and large scale/long term testing of their printers combined into making production parts.
I mean, the whole point of all this is the recycling part. you can buy a generic comb anywhere from anywhere :P that aside (using recycled parts for both) to each their own? they both have strengths. printers are amazing for prototyping. plus industrial injection molding machines don't need a person to operate the same way. the milling time should also be included for injection molding, but if you want large quantities it becomes negligible
When it comes to the cost breakdown, you went with the cheapest injection, molding machine and most expensive 3-D printing machine you can get three times the amount of bamboo lab A1 printers for the same money as the Prusa Mark 4’s
Timewise a fair comparison would be starting the 3d prints as soon as you place the order for the injection mold. how long to just start 3d printing compared to having to design the mold and order it, get it and then start working with it. The upside of 3d printing is that you can work as soon as you want but it will never compare to the efficiency of Injection molding (After having the mold). having said that, the rest of you a analysis is correct. I have a few 3d printers but i really want a Injection molding setup
i'm curious about how much does one mold cost and how long does it take to make from CNC machine, i think it's safe to say you need at least 4-5 mold for each time you inject plastic inside and wait for it to cool down before your take it out and re-use the same mold again.
They can work hand in hand, you 3d print the prototype and once you're happy with the design and used filler to and sanding to remove any imperfections on the 3d printed version you can the sand cast the item to make an aluminium mould to mass produce on the injection machine
This is sort of like asking a guy who only uses hammers to pound a screw into a piece of wood. A screwdriver works better. So many things missed. For instance: 1. Injection molding, the way you show it requires significant labor. A single person can operate a 3D print farm. Injection molding cleanup is significant. You know this because your eyeglasses require a lot of it. 2. The Bambu printer you show is at least as good as the MK4 and 1/4 the price. That's why print farms are switching to Bambu printers. 3. Clearly you have little to no experience with 3D printing as you've oriented the comb in the wrong direction. 4. Injection molding requires draft angles, gates, sprues, release agent and sometimes even ejector pins. Texturing molds is an art itself. More complicated molds require slides. None of this is necessary in 3D printing. 5. Fabricating tooling is typically an iterative process unless you have professional engineers. You need to understand shrinkage, material flow, flow welds, not to mention part clearances, final fit and finish. This takes more time and becomes more expensive every time you iterate. In contrast, 3D printing is ideal for creating iterative designs. 6. Injection molding creates significantly more waste because of these screws and gates created. So, it makes no sense to buy recycled material only and not have a way to recycle it yourself. You need to factor in those costs as well. 7. And lastly, I think you paid too much attention to the concept of time. My guess is you do not run your injection molding machines 24/7 or even a full 8 hours every day. It appears the only metric that you use to evaluate these two processes is manufacturing or print time and I believe that is a poor metric for a variety of reasons. First off, it takes a tremendous amount of time to fabricate a final tool for injection molding. That should be calculated into the evaluation process. Furthermore, the iterative tooling time and costs are substantial as well. And, labor time is a linear progression when scaling injection molding the way you show it. Not so with 3D printing. One more two people can manage a huge 3D printing farm. Bonus point: injection molding works once you have a complete designed finished, tooled, and ready for manufacturing. Because of this, it becomes more difficult to open a store with many, many different SKUs compared to 3D printing. For me, this is an injection molding fan video. Certainly injection molding has great advantages over 3D printing in some areas and vice versa. But looking at it through your own injection molded rose colored glasses doesn't provide a very objective review.
I saw a RUclips video somewhere that was able to spin filament out of PETE bottles by thinly slicing the bottle as it rotated. Could be a good way to get recycled filament for certain 3d prints, although I don't think PETE is generally as good for printing as PLA or ABS.
I'm not sure if it's a mistake or insincerity on your end but that's not a remotely fair test for the 3D printers. When you print single things that small you're going to limit the speed by the 'Minimum Layer Time' which is a complete non-issue when you're doing proper batches of several objects. In proper batches you'd print about 30-50g of material per hour which I assume comes out to be about 30-50 beads or ~3 combs per hour. Done correctly you might get 15hrs/day of effective production and thus you'd need ~5 of them to produce 9000 beads in 3 days. And as for the choice of printers, A1s (not 'Mini') are an excellent choice, they're both faster and more reliable than Prusas (which are last generation printers) and cost ~£300. And do you need to full time employees to run 5 printers? Hardly. It might be about 2 hours of work per day plus whatever post processing you need (which could be just about 0 to be honest). So that's about £120/day or £240/9000 beads saved in labour costs.
Oh, and you also compared the cost of the printers to 1 injection molding machine, instead of the 6 that you actually used. So all in all the total should have been *£9000* for the 6 injection molding machines compared to *~£1500* for the 5 Bambu A1s.
@@oyuyuy I'm pretty sure they scaled the ratio of printers vs injection molding machines. They mentioned something like 30+ machines to match the 6 injection molders.
Isn’t the purpose of your products to use recycled plastic so you’re reducing waste? And 3D printing can be SUPER wasteful so I feel like those comments are missing the entire point of your product and purpose? Your stuff business is super cool and I love that you make practical/quality stuff with recycled plastic. Would be awesome if you started using 3D print waste to make stuff (if you haven’t already)
Depending on what you're doing, 3d printing is great, and you can totally use it for mass production. For example, drawer handles, totally 3d printable. But it definitely has the drawbacks listed in this video, although the durability one is super overblown. It's only a problem if your part is like experiencing super high forces with tight design constraints. Which is actually not very many parts. Really the biggest thing is just the surface finish and the feature size limitations. You just can't make small things that look nice with fdm.
The old fashioned way will always be the better way. But 3d printing can still be well utilized for injection molds as modeling and sculpting can be done digitally faster than sculpting by hand and not worry about simetry. I would 3d print a base mesh and add clay to sculpt lightly over it for extra details and rid of those pesky layer lines. Then cast a mold from that. I would consider 3d printers an extension to the traditional ways for easier work flow.
Worth mentioning that the injection mini and mould price doesn't include VAT whereas the 3D printer does, so you need to add another 20% on top. One of the most annoying things about the sustainable design site is the surprise increase in cost when you get to checkout.
Now do an episode on mold making. How much does it cost to DIY a comb mold?
Depends of the CNC you're needing to carve, the aluminum sourcing, how clean you want your mold to be (with/without much layer lines for example if you're not using 5 axis). Also companies have to pay time spent to 3d design and test the molds prototypes, so it varies a lot if by "DIY" you means hobbyist or small lab.
From nothing, to a lot.
It can be done without a CNC. You can make a positive of the item (say, on a 3d printer) and then create a mold from high-temperature silicone. It does benefit a lot from being placed in a rigid shell (e.g. a metal blank) and it does have some wobble in fine details that needs to be taken into account.
That said, it's not easy; it took The Crafsman quite a few tries to get a working mold using this technique, but he has successfully done injection mold runs this way. But the cost of CNCs are dropping extremely rapidly, too, so this is not the price savings it once was when molds were several thousand dollars...
@@oasntetwhat's a good CNC to consider (I'm a normal hobbyist ... would buy something like a cheap A1 mini Style CNC 😀)
It probably all depends on your own skills set plus what materials and equipment you have to begin with
I had no idea that those curtains were for flies!!!
OMG same!!!!
I don’t get how they could be. Is the goal to keep the fly in one room or something?
@@TheOfficialOriginalChad It basically makes what the flies perceive as a solid wall so they don't go in. Plus they can't move them by themsleves so they can't go through.
never knew they were fly curtains. just thought it was the decorating trend at the time.
@@TheOfficialOriginalChadIt’s like a screen door that they have in America. It’s so you can open your door when it is very hot without flies coming into the house.
You missed one thing. How long does it take to make an ejection mold ? That needs to be added into the total time.
Exactly… 3d print from nothing vs mould from something. Also a resin printer would print the beads quicker than filament.
The molds they are using for the beads, comb and glasses could easily be cut from aluminum in a day.
@@lgenic yep. SLA printing would def be the fastest and cheapest for beads making I believe.
@@trygvij1604 Injection molding would still be the cheapest
@@yatyas72so you need a high quality CNC as well? 😜
Why did you print the comb in that orientation? Just off the top of my head, that would be the absolute worst orientation for it - the forces are going to be perpendicular to the layer lines and you'll break teeth, AND it would print much slower because you have to wait for the small layers to cool, AND you'd have a ton of stringing (potentially).
I used to be in industrial plastics - injection molding, blow molding, crown molding, the works. I'd say the biggest benefit of 3D printing is consistency and ease of use. We'd have machines that would be cranking out parts without issue all night, then someone 3 buildings away would sneeze and we'd spend the rest of the shift trying to get the parts going again. You'll sometimes get prints that don't want to cooperate, but I've never had the issues with even my cheap, ancient 3D printer that I had with the big injection molding machines.
But ultimately, you're right. Injection molding does one thing, it does it very well and very quickly. 3D printing does a nearly unlimited number of things, very slowly and with a rough finish. For now... I think the story will be very different in 20 years.
The thing you need to account for is the cost of machines. With basic optimizations, you can get the throughput of a 3d printer factory to be equivalent to an injection molding machine at the same cost. And that can be done today. Only once you are talking the absolutely massive machines that can spit out hundreds of thousands of parts per day does that end up favoring injection molding again, and only because you can micro optimize the material use and save enough money for it to make sense.
Lego bricks for example would be stupid to print as you would need to change their size so they are larger in order to be strong enough. Duplo bricks would make sense if they were printed.
3d printing excels where you want to be able to customize or personalize items. Not for mass scale manufacturing generally. So not a great comparison. But a fair point.
This needs investigating!
(Making a video recreating the experiment with 3d printing farm and sending the beads to quality control 🫠)
Doesn't help he used a mk4 instead of a bambu p1p/a1, would have leveled the scales. (speed)
Actually for the cost of one employee operating 3 mold machines, I can purchase 100 bambu A1 minis, pumping out 5 combs an hour each. That is 12000 combs a day max, far far far greater volume than what the small injection modling can do.
@elitewolverine if you can respool and clean and whatnot within 1-1 minute per printereafter every print and you can sequence the prints so you are continously scrape the beds and whatnot then you loop around every 100 mins... so max 7 loops a day. That is only 3500 combs my dude
@@elitewolverine You comb your hair with that 3d comb for year and I'll use the injection molded one. I guarantee you at the end of the year, yours will not have held up as well as the injection molded one.
You guys should collab with Slant3D on a 'challenge' to refine the scope of when to use 3d print farms vs. when to invest in injection moulding. I agree with your conclusions that each has their place. It'd be very entertaining to see two very passionate sides of the argument go head to head, though ... sorta like a heavy weight boxing match for plastic production!
3D printing and injection moulding have their use cases and I love the fact that you gents went through the pros and cons between the two technologies and processes. Use a 3D printer to help prototype a design with the intention of using injection moulding later for larger scale manufacturing. I'd imagine the aluminum injection moulds costs quite a bit of money and time to fabricate so using a 3D printer to iterate through your product design makes the most sense, minimizing the cost and time spent creating the moulds for injection moulding.
FDM and injection molding even compliment each other. I've used the DIY recycling techniques from this channel's videos to recycle my own 3d printing waste into useable parts. The panini press melting technique works great with supports/failed prints/printer poop. There are other "recycle your 3d prints" videos on youtube, but most of them don't get the quality marbling demonstrated in Brothers Make videos (sorting your plastic and careful folding makes for a much more visually striking final product)
That print orientation of the comb in the slicer is 100% engagement bait ;)
3D printing shines with custom tooling. You could make a simple pneumatic press with 3D printed parts for taking those beads off of the sprues all at once
Man! Legend you are!
Don't forget manual labor when calculating the price of injection molding, 3D printing is mostly automated leaving you free to do other things. Injection molding requires you to be there the entire time.
Hahaha, they literally show you asking this question and then answer it. 😂
@@OpalSea And they answer it wrong. They said "you have to maintain the printers" as if that takes nearly the same amount of time as operating the injectors. It absolutely does not. Source: we have shelves full of prusa XLs that I work on at my workplace, and I also work with a guy who runs a bambu farm.
You only get similar labor cost with unreliable printers. The prusa mark 4 used in the example might actually be _the_ most reliable printer that you can buy below enterprise grade.
@@Mindbulletz I've worked in injection molding shops with fully automated equipment that just requires someone check on it to swap the output bin when it's full, and refill the input hopper every few hours. Thousands upon thousands of perfectly clear medical-grade parts came out of that machine every shift.
The real story, which they talk about in the conclusion, is that for any given part, there's a volume of output where it makes sense to switch from FDM to injection.
moulds are expensive add another 5k for a cnc machine and probably £30-50 for material then your getting closer to equality
3d printing will always be faster for one offs or prototypes
injection moulding is always cheaper for mass production
Mold making is a specialty in its own right. Also don’t forget the cost of work holding, tool holding and the bits, you can sink a lot of money in those. The cost of the shop space it takes shouldn’t be ignored either.
Molds can be made very inexpensively as in this case where they have straight pull parts with split line molds. If you design the mold and just have it cut at a local machine shop out of 6061 or 7075 aluminum, you're only paying for machine time so the cost is quite cheap. I've done molds like this for several customers fishing lures, watch pieces, USB over molding, etc and they usually run a couple hundred dollars. You didn't have to buy and own all the equipment to do this.
You can always build a Milo, saves you about 3k to put towards stock for moulds!
Injection molding only has two things going for it, first is strength for small parts (3d prints are stronger for large parts) and cranking out excessive amounts of parts in short order. But you rarely get orders like that so it is almost always better to just maintain a stock.
@@SirSpence99 I don't know where your experience in injection molding comes from but rarely did we receive orders for less than several thousand pieces. In 25 years of being in injection molding I can count on one hand the amount of times molds were changed so much that they had to be redesigned or remade. Most were minor changes that took a day or two and we were back making parts. I have aluminum molds with 100's of thousands of parts made on them so expensive hardened steel molds are not required. Large parts for 3D printing aren't even comparable in quality to Injection Molded pieces. From surface finish to strength of parts. Where 3D Printing works in plastics is for prototyping and very short runs but once again there is NO COMPARISON in the quality and strength of a molded part.
If you want to make massive abounts of the same item then injection molding is better. If you are prototyping, making complex parts, short runs or a job shop, 3d printing is better. Making 3d filament is also a valid use to recycle plastic.
For the average person, they will get WAY more use out of a 3d printer than injection molding. For the small boutique recyclers trying to make the most product, the injection molding will make a lot of sence.
And when you say massive amounts, that starting point is at about 100k pieces. And even then, 3d printing is going to be competitive.
This example they have is the ideal setup for injection molding and the worst for 3d printing and they didn't even pretend to make it fair. Ask them how much they spent on machines...
@@SirSpence99 100k pieces?!! You do know you can get far less than that right? In the case of the combs you could get 200 pieces and the mold made quite inexpensively plus you could get reorders fairly quickly or even delivered seamlessly if you have known quantities spaced throughout the year or lifetime of the product. PLEASE SPEAK TO SOMETHING YOU KNOW ABOUT!
@@yatyas72 Generally it helps when you want to disagree with someone that you address what they said instead of something you made up.
Why don't you think for at least a second this time and not assume I am an idiot and might have a point. Assuming you aren't an idiot, you should be able to at least get an inkling for why your comment is irrelevant.
What’s the cost of molds against 3D printing files
If 3d printers could make parts cheaper and faster, then industry would have stopped plastic injection long time ago.
It can makes part at home, which is already impressive.
Shoe companies now have 3d printers, for designs that are impossible with injection moulding. It doesn't take much complexity to eliminate injection moulding as an option. I really like the option of both though, different use cases for sure, and recycling/ reusing has to be better then land fill.
@@Steve-bs7bo few shoes companies selling expensive shoes != the whole industry
@LucianoFoxtrot didn't say whole industry, it is new tech and needs to evolve. But major companies like Adidas and some start ups too.
@@Steve-bs7bo this is definitely not new
@@LucianoFoxtrot it is pretty new to the shoe industry. Printers and materials have evolved to the stage that it is now viable. These are not generally the hobby level machines or materials.
You should make a collab with Slant3D. You could design a functional part for injection molding while Gabe could design a part for the same function for FDM mass production and finally you could do the math and cross-check the forecasted costs. That would be something really interesting to watch...
The Crafsman has made some discoveries that could drive the cost of injection molds down significantly, especially for small batches. He got a couple blank molds made, and then slots high-temperature silicone molds (made from positives that are resin-printed) into those. So he can make injection molds at home. They won't last as long as CNC'd molds, but they can be iterated on for much, much cheaper.
What's the benefit of the blank molds? Hold the silicon molds?
@@Biru_to Yeah, they're a little floppy, so the extra support keeps them in place and helps resist the pressure from the injection process. He's had success with just backing with cardboard, but prefers the metal blanks for rigidity and repeatability.
@@oasntet Thanks for answering my question! Probably is worth it over something simple/cheap like cardboard / mdf when you do a lot of molding like he does. 👍
Great video, injection moulding can make usable things from recycled plastic, and 3D printers create prototype problem-solving solutions. In my opinion, they are difficult to compare, but you did a good job demonstrating it. Both have their place in a good markerspace ♻️
It takes 200 hrs (8 to 9 days) to print 9000 beads on my single Voron 3D printer (costs $600 to build) - this is actual print slicing calculation. Estimated with beads having an 8mm diameter and a 1.6mm hole. There is zero plastic waste, and total labour cost is about 45 minutes - 5 minutes to clean the print plate once daily for 9 times.
I'm not doubting that both have their pros and cons but I don't think you really give a fair comparison.
1. Nobody would print a comb standing on end the way you had it. Having it lay down would make it faster & stronger.
2. 100% infill does not add strength. See CNC Kitchens testing.
3. Print farms can be mostly unmanned. With automation the printers can be mounted at a 45° or greater angle. When the print finishes, it cools & releases from the bed, falling into a catch bin. The print head swees the bed to ensure the part fell into the bin & then continues to print the next part. This continues until it is out of filament. You can also use 5kg spools to do more without human labor.
If injection is your thing, then great. You do you, but you did put up a rather flimsy strawman.
Yep, and I see print farms getting into the bambulab printers I stead of the prusa. So the are also faster.
Don't worry about the waste from the 3D printer.
Just buy an injection molder and make the waste into beads :D
I have 3 3d printers (2 fdm, 1 resin) and run a small 3d printing service and I adore 3d printing, but 100% they're just not practical or appropriate for a lot of tasks. I'd never consider printing a comb because regardless of resin or filament or infill used it just won't have the structural integrity to be useful, especially for the long term compared to an injection moulded one, and especially compared to one which can be endlessly recycled.
I think the orientation used for the comb printing is pretty "wrong". The tines should be printed horizontally to give them strength. A bit a cleanup is needed on the bottom side to remove support material, though. That said, I haven't actually tried printing a comb.
13:59 Did you really want to print this comb in this orientation...? I think if you set it lying down you could get down to 20 minutes of printing or even less.
That mini Injection moulding machine is awesome! would love one of them!..... With the Injection moulding the mould is the slow bit right, you have to make the mould or buy it....
Yeah that wasn't included in their time factor. If it takes 3-6 weeks to get the mold that's a couple weeks the 3d printer has to print. I agree both have their place but I think the run volumes are higher than 1 off and are closer to 1000-10000
Don't forget the automatic open-close cycle of a typical cnc injection mold machine. What's being shown here is a job shop/hobbies injection mold process. Not one meant for production volumes.
Love that you're taking an honest look at both the strengths and weaknesses of the two methods!
Funnily enough, this is one of the most dishonest comparisons I've ever seen.
You guys actually inspired some of my work in molding 3D printed waste into parts for my products. So best of both worlds from this video. Keep up the good work guys!
you should make some kind of punch/cleave that fits the exact shape of the beads after taking them out of the mould, so all you'd have to do to get off the ring that holds them and the excess is push down on it with a lever or something similar
I say this every time I see someone review a product that was made using a 3D printer: 3D printers are great for prototyping and iterating on an initial design, but should not be used for a finished product. The layer lines look awful and injection molded parts are just higher quality. If I'm spending my hard earned money on a product, I want it to look and feel nice. You just can't do that with a 3D printer without lots of post processing work.
This isnt even a quantity vs quantity problem, injection molding makes solid seamless parts that have a very good quality hand-feel, 3D printing just doesn't hold up to that or the structural strength of a 1-shot part. 3D printing is a compromise on all these, in order to do it at home for cheap. On the other hand, we have things like 'fuzzy skin' to help hide layers now, textured build plates. And the ability to print hollow or dense selectively.
If you print the comb laying down, I can safely say the strength of that comb on a 3d print is the same strength or super close to it, using similar materials.
You should try holding a 3d printed object that was printed with said "fuzzy skin". It has a much, much nicer feel than any injection molded part. Night and day difference. And yes, it does completely get rid of seams and layers.
@@SirSpence99 I mentioned fuzzy skin at the end of my prior comment. It really depends on what the part is. I kinda think the majority of beads are desired to be smooth and not fuzzy textured though, but it probably has its uses there as well.
I'm currently in the process of making molds for glasses frames. I used my 3d printer to print the items and now I'm about to create the molds using the 3d printed frames so I can make Epoxy resin final frames. I would love the equipment to do injection molds in the future it just looks really fun to me.
Hi Brothers make! I've been a subscriber for ages. I've been working on a machine for the past 3 years that anyone with a small shed and limited tools can make (for very low cost out of salvaged parts). I'm working on making fully recycled 3d printer filament from common house hold plastic. I've also seen that some people have been adding pellet extruders on their printers to avoid filament all together (as pellets would be wayyy easier to make). Love your vids, keep it up (:
I also think a good answer to the question is: this is what you like doing. If you enjoy making this way and like the finished result, keep doing what you’re doing
LOVE THE VIDEOS!! Your guys injections are so clean. We are struggling with flashing especially with the beads mould. We have tightened the mould as much as we dare but it still happens. thanks Mike
*LOVE THE COMB MIC HOLDER* 😂❤
I love your way better. The point is *recycling* so this is the best way to produce them for y’all. Love your channel and what you stand for! Keep it up! Hugz, Tree
It's a classic! 🗣🎶🎙
Okay, I think the main difference between these is that injection moulding is a specialised process, whereas 3D printing is a jack-of-all-trades (master of none).
If I wanted to create a new item, like a new keychain charm, and I owned a 3D printer, I could design it in CAD/Blender have it by End of day.
Whereas for injection moulding you need to machine the mould before you can start production, and you need to mass produce it to make it worth the cost of producing the mould.
The bambu lab a1 mini is actually better than the prusa mk4, surprising, but true
It's also really important to think of failure modes. Delamination can be gradual and also prone to material detachment, maybe even dangerous for lungs when fillers are used. Always think of how things will fail if you are selling them.
I've worked in injection molding for 25 yrs. I bought my 1st 3D printer 3 weeks ago.
Injection Molding is far superior but 3D printing allows me to make parts, tools, toys, etc. that are unique and useful for me in my home workshop.
If I was a maker selling product made of plastic, I would go with IMMs.
I have a lot to ask . Where do you get those molds from? How do you give the melted plastic a particular colour? And where did you get the machine that injects the plastic in to the mold ?
3d printing in all of its forms is for prototypes, oneoffs, and low volume batches. MJF and or SLS is probably what would lend itself most easily to your application, and might even be relatively cost competitive for your smaller parts like those beads, but is definitely far from recycled lol.
Something you guys might like though is making resin printed injection mold tooling for second stage prototyping and low volume batches for limited editions. So that kind of workflow might look like this: first stage prototypes on desktop FDM printer, second stage prototype from an MJF machine, third stage prototype from resin printed injection mold tooling. FDM prototypes are virtually free so you can make as many as you need to get the look and feel you're after. MJF is relatively inexpensive, and the mechanical properties are going to be very close to what you're injection molding, so you'll get a really good idea how the actual article would function in real world use, so you could use those for destructive testing and simulating wear. There are even flexibles that closely mimic rubber. Then your resin printed mold tooling will test the final dimensions, draft angles, venting, ejection pin locations, etc. If you don't have any issues with the resin tooling then you can be a lot more confident in investing in CNC tooling.
Resin tooling is also really good for injection molded silicone. Since there's no heat involved, and the silicone is so soft, those can actually last a long time. Like a tool you print with a 100 dollar bottle of resin might last as long as the iteration of the part it's making and save you thousands.
You made some good points, but a more fair comparison would be: to use not a ready made machine like prusa or bambu, which are not used by big proffessional farms (except for prusa obviously), but diy machines that are cheap, replicatable and easy to repair. A good diy option could cost up to 400 EUR for a bare minimum machine printing in pla or petg. And you would not need it to print fast. Additionally, throw a custom gcode in the mix for releasing parts, so as soon the print is finished, the printer yanks the part in a front tray as to eliminate human interaction to release prints. Then the print sequence would start again until you have the desired amount of prints. Second, that would also mean your 3d files must be made in a way as to allow easy release of parts by the printhead. That would mean printing 1 bead at a time, but continuously for three days - no supports, no brim. You correctly mentioned that 3d printing allows you to make things that cannot be possible with other means of manufacturing. And this is a bonus many do not use i.e. everyone tries to print parts that are hard to print but easy to injection mold thus many use supports, are flimsy and just bad. A combination of those two points would reduce the cost of the print farm substancially and eliminate any post work. Now, that would still give you a subpar result comparing to a molded bead and less color variation options, but it would definetily lower the price of the print farm. However, with 3d printing you can also add various textures on the fly. Grainy, wavy etc. For injection molded parts you would need a new mold and afaik molds are a bit limited in terms of textures unless you shill a lot of money for it to be made on specialized cnc machines. I may be wrong on this one.
Additionally , it would be fair to assume that a print farm would need more space to operate. So that is an expense, especially if you need to heat the premises. That should also be thrown in the mix. You cant squeeze many printers in a small workshop. On the other hand, a big space could also mean that a conpany could invest in a filament maker and recycle filaments in the house.
And lets be real , 20 pounds per filament roll is a retail price. For a business, you could easily go dirt cheap if buying in bulk if we are talking about 1 color, especially when you buy 3kg rolls. I mean, i buy my filament in single color pla for 10 euros if i buy 10 rolls or smth. A big business can do lower, say 6-8 eur.
if you used a resin printer it would be quicker because you can put more on the build plate and it doesn't change the speed
But their concern involves sustainability and recyclability. Resin isn't recyclable, it can't be melted and reformed into new parts.
I am using 3D printing for prototyping. The final will be injection molded or nylon SLS printed depending on volume.
That’s a really cool video and I think the one thing you missed is that aesthetically the moulded ones look and probably feel way better too. On saying that I have another user for the beads I printed my own and use them on the drawstring in sweat shorts as I find every time they go in the wash they end up pulled into the waistband. Keep doing your thing boys as always super proud of you ❤️
So fun! Didn't know that those beaded doorways had a purpose!
Figure eight knits are great for holding ghings from slipping through a hole, they have more bulk than standard overhand/granny knots.
The curtain turned out great!
Never injected molded before, but I want to, now! 😅
Good video. I have been in 3D printing for 5 years and agree with your results. I rarely print over 5 or 10 copies of something. This is my hobby and I enjoy testing different designs, so for me this is the way to go. I can see a design and be running it in 5 or 10 minutes.
As someone who has actual buckets of 3D printing waste I've been accumulating since 2016, I'm always looking for ways to both optimize cost and optimize material usage in a way that makes sense. This channel has always been insanely helpful for figuring out what to do with all of it. Anyone saying 3D printing is better is clearly just misinformed about strengths and weaknesses of various fabrication techniques.
Actually there are ceramic filled resins intended to print molds for low number batches (like a few hundreds of injected parts). With a price about 250€/liter this might be an alternative to aluminium molds if you want just a few hundreds of pieces. Still you get all the advantages of injection molding.
On the other hand prototyping for injection molding is not always easy to do. The object has to be able to be released without much efford. Complex geometrys are not easy to do or maybe even impossible with injection molding. However, if the geometry of the object allows injection molding and you need a bigger number of the same part, injection molding is the way to go.
It is not 3d printing or injection molding. Always use the method best for the special project you want to do. And also consider a CNC mil and searching for an industrial mass produced product you can simply take for a start and modify it with some milling... Having all 3 technologys available gives you much more power to do everything you want.
It was quite nice to see the prices for small injection molding machines have come down quite a lot. It´s in the price range for hobbyists now. Still, while of course an air-compressor is the professional way to do it: Would it be possible to use a long lever instead to press the molded plastic in? For a hobbyist at home an air-compressor might cause problems with neighbours...
Bring them all together ;) You can start collecting aluminum cans too and sand cast your own injection molds… using a 3d printer to make the model for the sand casting… then injection for mass production
You could speed up the 3D print quite a lot by printing it flat on the bed, 0% infill, and enough walls to fill in the difference. Also, comes don't need fine detail, so you could use a 0.6 or 0.8 nozzle instead of the standard 0.4. Still won't approach the injection molding speeds, but will be a lot faster for prototyping.
There are a lot of items you could never make with injection molding that you can 3D print. Plus there are industrial SLA printers that are now matching injection speed and cost.
I work in plastic injection molding actually and yes it is great for making alot of the same part quickly, and efficiently but being able to make multiple things in a small space is also great maybe time consuming and there are ways to recycle waste
When doing mass production, injection moulding is definitely the solution. If you won’t be doing mass quantities, there’s no way to justify the prohibitively expensive mould. Because of this fact, determining which is better is a little like trying to decide if apples are better than oranges. Each has specific benefits the other cannot match. Now, if you can find a way to 3D print a mould to use in injection moulding, you’ll really have something worth something.
Lol for a person with a 3D printer and been into printing since 2017, you guys are where it's at for production and part strength period.
Adapting @ShaketheFuture's "Print Wave Metal Casting" technique, where he 3D prints a negative of a mold with 0% infill and then converts it into a metal-casting mold, seems like a way to marry your 3D printer and injection molding machine into a combo system with most of the flexibility of a 3D printer and the scale production of injection molding. I would love to see you guys try and experiment with DIY poured injection molds using 3D printed framing. IF it can be done and can produce even passable-quality parts in quantities of 50 or so before needing to retire the mold, you will have seriously changed the game in small-run production.
Brothers, fly curtains is a clever use of recycled plastic! Congratulations!
I wonder if there is a market for beaded window curtains. The idea is that they would function as sheer curtains, letting in a bit of light.
My biggest question is, where do you get your moulds from?
How expensive is it? Without the moulds, the whole thing keeps me from doing it.
Without the moulds, I have the impression that you have to do a lot of manual work afterwards, which I don't have most of the equipment for.
HOWEVER you doing the work or letting the printer do the work, while you do other work, makes it a lot of difference and is key here! Besides that there is a big cost to making the molds, something you don't have to worry about with 3d printing. And you can make way more products if you print stacked, and since you don't work day and night, well your printer will just keep going!
BRAVO!! First time to your channel. I've done injection molding for 25 years and have come to the same conclusion. I'm sure someone had already beat me to it but Slant3d really pushes the 3d print farm but in scale and quality you cannot even compare the two. Great job! You have a new subscriber. BTW- I do love my 3d printers but use them mainly for custom and one offs
I noticed in you example of 3D printing your comb, you had in set vertically. It would print much faster laid flat, plus the teeth would be stronger. Also, did you setup multiple combs per print? Obviously injection molding is optimal for the combs; better strength, and faster overall, but I don't think you gave 3D printing it's absolute best potential.
Probably one of the easiest plastics to recycle is PET, because it can be recycled over and over again.
Whereas PLA kind of breaks down if you try to recycle it multiple times.
I like both. I want to eventually made an injection machine so I can recycle my supports into useful things
Combo idea. 3d print your mold. Then make a box that can hold the mold for the injection mold. Then use clay or porcelain to clone the plastic mold and the set into the injection box.
What about the molds ? Aren't they super expensive ?
Yeah but imagine you just needed one thing.
3D printing is good for making intricate designs, you basically only need a digital modelling /sculpting app on your computer.
BUT extruding machines are the way to go, if you want to mass produce an object.
I guess a 3D printer could be used to make a prototype for a mold, which in turn will be used in the extrusion process.
A UV bug trap will solve the fly issue fast. Bug zappers can cause insect body parts to be strewn across a wide area as their bodies explode in the zapper. Another way to keep them out is to use a high speed blower placed at the top of the doorway. This will create an air curtain they can get through. Effective against flying and many crawling bugs.
Yeah, each have their use cases and in most cases they're complementary. Iterative prototyping on the 3D printer, mass production on the injection moulds, if you so wish. Sometimes a 3D print is more than good enough for commercial use, even as functional parts.
If doing iterative design using a 3D printer, you have to keep in mind injection molding limitations, because there are a lot of forms that can't be injection molded, but can be 3D printed. So it requires someone with experience in both methods.
@@yeroca Indeed, one of the few things I hear about is the 'draft angle' which is obviously not an issue with 3D printing.
I think this is a great video, I would say you have missed out a way of batching on the 3D printer. You have a much larger print area on a 3D printer. You could print across the whole bed of the printer and then with very small infill between layers print another layer of 3D prints as the printers can print in 3D where as the injection mold is set in one axis.
There is the other issue that a awful lot of waste material is created for each mold due to the plastic channels. This is also created in part on the 3D printer but can be dramatically reduced compared to the mold, in the case of the beads.
Still a great video and an area of work I had not realised that had become so affordable to enter
Cool video. I didn't know injection molding was as accessible as you're saying it is. If I ever make a hit design and need to make lots of something it's good to know
the machine should suit the product and the production environment. For example the inexpensive injection mold machine can have more material throughput but it requires manual operation. The 3d printer can melt and deposit material slower, but it's automated. The comb could have been 3d printed on it's side, tweaked for 3d printing so that many of them would fit on the build plate, and then printed while you sleep or do something else productive. You couldn't run the injection mould machine while you sleep. When it comes to cost, a 3d printer can work for a lot cheaper than a human per hour.
Inject molding produces better part with longer preparation time and high upfront cost, while 3D print just straight goes from 3D modeling to actual product in a few hours but the quality won't match inject mold.
In your case, 3D print is click and go and wait while you consistently manually inject moding.
Touched on it a bit at the end, but IMO the molds would be the biggest point if you are comparing the two methods. You can 3D print anything using the same machine, but you have to buy a new mold for each unique design. And I imagine prototyping designs would be a pain. But I’m here for the sustainability and injection molding of recycled materials is the way to go
I teach Materials Engineering at my local University. Our department is fortunate to have one of the top polymers researchers in the nation. This semester we gave the students a lab assignment in which we tensile tested hundreds of 3D printed dogbone specimens. Each samples feed rate, head temp, bed temp, and print location was carefully recorded, and they then analyzed the results for changes in the stress-strain curve as each of the parameters above was varied. At the molecular level, polymers are made up of long chains of molecules, like a bunch of snakes in a pile. Add energy to them and the snakes start to slither past each other. In a filament print, each layer cools before the next layer is put down. The snakes in the bottom layer are frozen, and the new layer's snakes can't intertwine with them. The layers don't truly weld. All the material for an injection molded part is introduced in a fluid state at one time, and the snakes can knot up however they want. We predicted that the lack of true welding between layers would significantly decrease the strength of the part produced. We used a data set taken from an injection molded set of dogbones as a control.
The results were interesting. Across the board, regardless of parameter settings, the 3d printed parts were significantly weaker than the injection molded samples. Our printer featured an enclosed print bed, which allowed us to assume convection heat transfer was negligible. Despite this, the data showed wildly different tensile strengths and ultimate strengths based on the position on the bed it was printed as well. The difference between the left and right sides was a nearly 20 MPa jump. We printed with PLA, which at it's high end is only about 57KPa. More than a third of the strength was lost compared to the Injection Molded samples.
For any real design purpose other than a prototype or protype, injection molded polymers will stomp all over a 3D print. However, there are some other uses for 3D printing that have proven to be fantastic. For example, a few years ago our students built a 3D printer that prints solid rocket propellants. The thrust pattern of a rocket can be controlled by altering the shape of the void at the center of the propellant. 3D printing makes it easy to adjust the thrust patterns. A current group of students is now looking to adapt the propellant printer design to work with mining explosives to produce precisely shaped charges. I'm taking that one home if they can get it to work.
I'm not picking sides in a YT comment thread, just thought people here would appreciate what we discovered.
Fascinating information! Thank you for sharing
Aren't the people saying 3D printers are better completely missing the point? Have they just watched about 3 minutes of your content? It makes no sense!
For me, as a model maker, a 3D printer is perfect as I can print out XYZ for a project whenever I need it, with the added bonus that I can use the waste plastic on scratch-builds! You've no idea the stuff I've got stored up in boxes and bags just waiting to be used. I've trained my Mum really well and she'll now ask me if I can use something before committing it to the recycling bin! "Why yes Mother, that old thingy will make an excellent rocket ship engine, I shall put it the metric ton of other crap I have!" 🤣
I've been meaning to leave a comment for a while actually, just saying how nice it wad to meet you two at Makers Central in May! My Mum was incredibly impressed by the glasses and just your general commitment to help keep plastic waste to a minimum. I know you were very busy, but I appreciate the time you took to talk to us, so thanks for that! It'd be amazing if you could be on stage next year. I'm sure many people would be interested in hearing all about what you do and how you do it. Maybe have a word with Nick Zammeti on the How To app? Anyway, just wanted to say that. ☺
And yes, it was Mathew Kelly! Absolute legend! Used to watch him on kids TV back in the 80's. That dates me!
Take it easy guys!
anything that falls into the category of 'crap that blows in the wind' things like syringes, plastic bags, beads, and whatnot are better off molded for sure, 3d printing can't compete at such immense volumes. For beads in particular though something that doesn't require post processing is probably better, maybe some kind of weird multi step hot forming/extrusion setup would work? I'm not sure.
I love this video. You nailed it when you said that they're both good for specific things. Also did you know that you CAN recycle filament scrap? Ive been doing it recently because of your videos!
You forgot to add the 3d printing time, the shredding time, and the sifting and sorting time to get the plastic to use in the injection molding machine.
I think the 5 money units per kilo cited for buying recycled pellets factors all that in. He mentioned that at 11:50
You can buy injection molding pellets, about 10 times cheaper than filament.
@@FlintStone-c3s in very large quantities yes.
A fair comparison would be to run the printer while you wait for the mould to be machined ;-) Or modify the product slightly so you need a different mould, then wait some weeks for them...
3D Printers can print almost any random 3d object from scratch. With no additional cost and hardware... Injection mold can replicate what's carved in the mold an unlimited amount of time, very fast. But you need do carve the mold, which normally is a third-party service that is expensive and takes time do be made.
Both have their place. And 3d prints are not always hollow in center. Depends what you do in settings.
I love my 3d printer, but I will admit it's not always the tool for the job. Especially at scale. (Though spherical beads and printing combs vertically are terrible use cases due to print stability) There is a local company near me that makes filament including the cheapest recycled filament I've seen and it's good quality; never had a single clog with it.
A lot of people say that Prusa should move to more injection molded parts to drive cost down, but whilst it might lower cost a little, for them 3d printing their parts has the added benefit of QC and large scale/long term testing of their printers combined into making production parts.
I mean, the whole point of all this is the recycling part. you can buy a generic comb anywhere from anywhere :P
that aside (using recycled parts for both) to each their own? they both have strengths. printers are amazing for prototyping. plus industrial injection molding machines don't need a person to operate the same way.
the milling time should also be included for injection molding, but if you want large quantities it becomes negligible
Loved the video. For hobbyists, injection moulding is too expensive unfortunately. But how you guys explained, 👍
When it comes to the cost breakdown, you went with the cheapest injection, molding machine and most expensive 3-D printing machine you can get three times the amount of bamboo lab A1 printers for the same money as the Prusa Mark 4’s
You should build a press that you fit the injection molded beads into and it could cut them all at once
Timewise a fair comparison would be starting the 3d prints as soon as you place the order for the injection mold.
how long to just start 3d printing compared to having to design the mold and order it, get it and then start working with it.
The upside of 3d printing is that you can work as soon as you want but it will never compare to the efficiency of Injection molding (After having the mold).
having said that, the rest of you a analysis is correct.
I have a few 3d printers but i really want a Injection molding setup
i'm curious about how much does one mold cost and how long does it take to make from CNC machine, i think it's safe to say you need at least 4-5 mold for each time you inject plastic inside and wait for it to cool down before your take it out and re-use the same mold again.
If you 3d print the comb laying down on the build plate it would take a lot less time and it would be more resistant
They can work hand in hand, you 3d print the prototype and once you're happy with the design and used filler to and sanding to remove any imperfections on the 3d printed version you can the sand cast the item to make an aluminium mould to mass produce on the injection machine
This is sort of like asking a guy who only uses hammers to pound a screw into a piece of wood. A screwdriver works better. So many things missed. For instance:
1. Injection molding, the way you show it requires significant labor. A single person can operate a 3D print farm. Injection molding cleanup is significant. You know this because your eyeglasses require a lot of it.
2. The Bambu printer you show is at least as good as the MK4 and 1/4 the price. That's why print farms are switching to Bambu printers.
3. Clearly you have little to no experience with 3D printing as you've oriented the comb in the wrong direction.
4. Injection molding requires draft angles, gates, sprues, release agent and sometimes even ejector pins. Texturing molds is an art itself. More complicated molds require slides. None of this is necessary in 3D printing.
5. Fabricating tooling is typically an iterative process unless you have professional engineers. You need to understand shrinkage, material flow, flow welds, not to mention part clearances, final fit and finish. This takes more time and becomes more expensive every time you iterate. In contrast, 3D printing is ideal for creating iterative designs.
6. Injection molding creates significantly more waste because of these screws and gates created. So, it makes no sense to buy recycled material only and not have a way to recycle it yourself. You need to factor in those costs as well.
7. And lastly, I think you paid too much attention to the concept of time. My guess is you do not run your injection molding machines 24/7 or even a full 8 hours every day. It appears the only metric that you use to evaluate these two processes is manufacturing or print time and I believe that is a poor metric for a variety of reasons. First off, it takes a tremendous amount of time to fabricate a final tool for injection molding. That should be calculated into the evaluation process. Furthermore, the iterative tooling time and costs are substantial as well. And, labor time is a linear progression when scaling injection molding the way you show it. Not so with 3D printing. One more two people can manage a huge 3D printing farm.
Bonus point: injection molding works once you have a complete designed finished, tooled, and ready for manufacturing. Because of this, it becomes more difficult to open a store with many, many different SKUs compared to 3D printing.
For me, this is an injection molding fan video. Certainly injection molding has great advantages over 3D printing in some areas and vice versa. But looking at it through your own injection molded rose colored glasses doesn't provide a very objective review.
I saw a RUclips video somewhere that was able to spin filament out of PETE bottles by thinly slicing the bottle as it rotated. Could be a good way to get recycled filament for certain 3d prints, although I don't think PETE is generally as good for printing as PLA or ABS.
I'm not sure if it's a mistake or insincerity on your end but that's not a remotely fair test for the 3D printers. When you print single things that small you're going to limit the speed by the 'Minimum Layer Time' which is a complete non-issue when you're doing proper batches of several objects. In proper batches you'd print about 30-50g of material per hour which I assume comes out to be about 30-50 beads or ~3 combs per hour.
Done correctly you might get 15hrs/day of effective production and thus you'd need ~5 of them to produce 9000 beads in 3 days. And as for the choice of printers, A1s (not 'Mini') are an excellent choice, they're both faster and more reliable than Prusas (which are last generation printers) and cost ~£300.
And do you need to full time employees to run 5 printers? Hardly. It might be about 2 hours of work per day plus whatever post processing you need (which could be just about 0 to be honest). So that's about £120/day or £240/9000 beads saved in labour costs.
Oh, and you also compared the cost of the printers to 1 injection molding machine, instead of the 6 that you actually used. So all in all the total should have been *£9000* for the 6 injection molding machines compared to *~£1500* for the 5 Bambu A1s.
@@oyuyuy I'm pretty sure they scaled the ratio of printers vs injection molding machines. They mentioned something like 30+ machines to match the 6 injection molders.
@@JeffDM You still only need 5 £300-printers to match those 6 injection moulders
Isn’t the purpose of your products to use recycled plastic so you’re reducing waste? And 3D printing can be SUPER wasteful so I feel like those comments are missing the entire point of your product and purpose? Your stuff business is super cool and I love that you make practical/quality stuff with recycled plastic.
Would be awesome if you started using 3D print waste to make stuff (if you haven’t already)
Loved the brake down and the recycling side of it❤ 3d printing is good for prototypes and 1 off's ❤ grait brake down
We all worry about shrinkage…
Depending on what you're doing, 3d printing is great, and you can totally use it for mass production. For example, drawer handles, totally 3d printable. But it definitely has the drawbacks listed in this video, although the durability one is super overblown. It's only a problem if your part is like experiencing super high forces with tight design constraints. Which is actually not very many parts. Really the biggest thing is just the surface finish and the feature size limitations. You just can't make small things that look nice with fdm.
The old fashioned way will always be the better way. But 3d printing can still be well utilized for injection molds as modeling and sculpting can be done digitally faster than sculpting by hand and not worry about simetry. I would 3d print a base mesh and add clay to sculpt lightly over it for extra details and rid of those pesky layer lines. Then cast a mold from that. I would consider 3d printers an extension to the traditional ways for easier work flow.
Worth mentioning that the injection mini and mould price doesn't include VAT whereas the 3D printer does, so you need to add another 20% on top. One of the most annoying things about the sustainable design site is the surprise increase in cost when you get to checkout.
That’s something we overlooked. Thanks for the info - we’ll add that into the description