I like the sleeves up walk the walk, reading and seeing a process is one thing but trying it and doing it with any level of success it priceless. Cheers!
During the 1960's, I was in Graduate School The machinist used liquid Nitrogen to cool down Teflon rods to cut threads in the rod. This allowed a precision cut in the then slickest substance on Earth!
This technique is probably not used as much anymore because there are plenty of options for making parts like this using a 3D Printer. The idea itself has a lot of merit, and it's great to see these types of manufacturing techniques demonstrated. Keep up the good work! Your videos are fascinating.
I wouldn't be so quick to write this off as an outdated technique; while filament extrusion printers have become incredibly common, you can't make anything but ABS or PLA parts. The great thing about this is that you can directly create complex one-off parts out of various elastic or soft materials with parts you basically have laying around, assuming you have a mill.
Additive machining may be a revolutionary process, but it isn't the end-all be-all of manufacturing processes. Mills and lathes aren't going to be going anywhere anytime soon.
Ryan Willis You could possibly print parts like this on an extrusion type 3D printer using a thermoplastic elastomer filament like Filaflex or Orbi-Tech TPE. While we are on the subject of filament materials, there are others too, like filaments based on nylon, High impact polystyrene(HIPS), polyvinyl alcohol(PVA) and polyethylene terephthalate(PET), polymer composites containing carbon fibers, wood dust, chalk etc, and filaments for printing foam/porous rubber(Basically TPE particulates in a PVA filament, the PVA is washed out with hot water or a suitable solvent after printing, leaving a porous object made from a TPE). Other 3D printing processes can handle other materials too, However, I agree that 3D printing is just another tool, not the ultimate production process, there will always be other processes that may be better on some things, though 3D printing may still play a part as a step in a more traditional process, you can 3D print a model for making molds for casting, for example.
For the price of a good 3D printer, you can have an excellent milling machine and the capabilities to machine everything known to man(almost). Plus you can make gears on some milling machines, new bedstocks for the same machine, pulleys, everything a lathe can do as well as flat surfaces. Lathes can't make themselves, milling machines can.
Wicked cool. No pun intended at all. Seriously, I love your channel so much. You touch on everything interesting, never anything boring and explain the science in a way that anyone could understand. So glad I stumbled cross your page months ago :3
I was working on a project that needed custom boots. I found some tie rod end boots that almost worked, but the smaller hole was too small. However, remembering this video, I used some liquid CO2 to cool the boot down, allowing me to use a very bi to drill out the hole. Thanks for sharing your ideas and making these great videos. If you are interested, I did make a video on what I did: ruclips.net/video/hZKY56i-D34/видео.html
Very interesting setup. At the research lab I worked in at university (as a lowly undergrad ) one grad student needed to drill 12" long holes in a block of neoprene. I think the mechanical engineer who ran the lab knew about this method. He poured liquid Nitrogen on the neoprene as the cutter went through it. They used a 3/8" Dia. steel tube that had one end sharpened. They got good results. The holes through the neoprene were for simulating blood vessels. Not sure how that experiment turned out.
Surprised no one has developed an open source head hardware and software for a CNC to cut like a Cricut or Zund cnc knife cutters. Never seen this before. Interesting and thanks for sharing!
Hi, Ben. I'd give your ice-vice technique another try with internal passages in the alu plate: water the plate and place your rubber stock onto the plate, run the coolant thru the plate and get it cold. Apparently, this won't work that well with thick rubber pieces, but I'd expect it to perform rather well with something similar to what you've shown. And no more stickin clamps!
Very nice, silicone(and neoprene) just got a lot more useful! Also I think Machinable ice could be really handy for lost casting cooler materials, rather than firing a lost wax ceramic mold for metals. Do you think there is a good dissolvent that would make it machine better when frozen? Might be worth playing around with
I'm curious to know what tolerances you were looking to achieve in milling the chilled rubber? As a fitter & turner specializing in plastics injection mold making every dimension required a nominal shrinkage rate added to the finished product size - to compensate for plastic shrinkage as it shrank from 200+ degrees C. to room temperature. We used shrinkage rates of anywhere from 1.02% to 1.2%. So did you have to calculate any subsequent machining 'shrinkages' to compensate for the chilling of the rubber?
Depends on the material, exactly how much any given material varies from another I wouldn't know. 'Coefficient of thermal expansion' should be a useful search term, otherwise, as previously mentioned, 'guess and check' methodology might be possible.
Ben, with your hobbies you are remarkably busy and you know no limits. I would ask which tendency came first if it weren't pointless; thanks for sharing
Thanks! I sometimes feel guilty after spending a chunk of time doing "nothing" ie reading on the internet or similar activities that have no observable output. It's a nice personality feature to have when productivity counts, but has its problems as well.
Very neat. Thanks for sharing. How much does the material shrink when it's cooled, and did you have to account for the shrinkage when milling the part?
In my Physisc Institute in Torun (Poland) since 70' rubber is machined using liquid nitrogen. Of course there wasn't CNC, but this method gives very precise parts. We made liquid nitrogen in our condensing unit so it was very cheap method of chilling.
This is very interesting. I think they make CNC tools with holes in the tool to flow LN2 through the head. It also might be better to set up a open tray and CNC the part in a bath of LN2. Using ice to stick it down is brilliant. For neoprene because it is permeable putting it in a pressure cooker for a few minutes might work well. The water saturated part when frozen should cut like frozen butter.
I have cut nonfrozen rubber on a lathe using very high rake, almost knife-like cutting tools made of high-speed steel with generous relief angles on all too; surfaces at rather high speeds that I thought kept the rubber against the tool with centrifugal force. I used an oil-in-water flood lubricant that made it cut much better. I expect the water, not the oil, helped the cutting. I arrived at the method through desperation. I would have used your method of dry ice and alcohol had I known of it.
Great thanks a lot. Now next best thing is to use a rubber resin and print it in SLA printer or 3D printed mold and silicon rubber. If we want a specific rubber material your method would be the best.
I have made hundreds of complex close tolerance soft rubber parts for the submarine industry using conventional Dremel grinding wheels and a high speed spindle (in a Lathe OR Mill). You just need to think outside the box. Trust me, try it
Sparey's The Amateur's Lathe, suggests that rubber can be cut on a manual lathe using stanley knife blades. Something akin to a flycutter might work well for "milling"
A little tip for the pump. A little peristaltic pump using silicone tubing will solve some of your problems, just the flow rate could be to small. I make them usually from 5mm-MDF if it needs to be cheap (coping saw and drill press). Lasercut acrylics if I have some more budget on a project.
That's a neat way to deal with needing rubber parts in a hurry, and in low quantities. Have you done this long enough to get a sense of how the tooling holds up at low temp? I could imagine the tool chipping if the rubber got hard enough...
If you're interested in this kind of thing, you should research Intraocular Lenses (used in cataract surgery). The state of the art material that is used in these lenses is a soft acrylic (harder than the neoprene shown here, but still pretty soft). The most common way that these are made is by cryo lathing the lenses. The optic diameter is about 6mm in diameter, and using the cryo lathing process, you can cut a near optic quality surface.
THAT IS MY SALVATION! For years I tortured myslef by using liquid nitrogen to freze the rubber. This gave me little time for machining! And I see this video after it is 8 years online!
I glued a piece of aluminum to another piece of aluminum with orange silicone RTV and then chilled it down with liquid nitrogen and tapped it with a hammer. It broke right off. So there is a temperature where silicone will get cold enough that you could cut it, but it may be too brittle to survive.
Very very cool stuff! Another method, at least if you're dealing with things like these and you happen to have a laser cutter, well, you can see where I'm going. Only downside to that is that it's a very dirty process, creates a lot of blackened particles everywhere which needs to be vigorously scrubbed off. What would you think about building a liquid cooled plate, basically running coolant through channels cut through the plate to supercool it. Maybe it's a bit like the ice vise you talk about, and I don't know if it would get cold enough to chill the rubber properly, but food for thought at least. Cheers!
I have borrowed and used a cold gun while milling hardened material with a tungsten carbide end mill. I am an apprentice toolmaker so I have only 10 months experience machining. So I think the tool steel was cooled way better than using liquid coolant. Doing some research I found out they are easy to build and can draw temperatures to freezing point. Maybe you can freeze the rubber using a cold gun. Sounds like a future project. No?
I make some parts that are essentially Tygon tubing (64 Shore A) with countersunk (internal chamfered) ends. They should be injection molded, but the short run manufacturing is too low a volume to justify molding. I put them in the freezer in the kitchen. I manufacture them in batches of 20 at a time. Any more than that and they thaw in the summer and the cut quality is bad. I enjoyed seeing your dry ice and alcohol machining technique. Thanks! I had previously considered a small Styrofoam box with dry ice, but the freezer compartment of my fridge is good enough for my needs. If I'm in a hurry, I'll sometimes dunk the parts in ice water to facilitate the heat transfer and machine them a bit wet.
Venezuelan 17 years boy over here. I have a couple of questions that I would like to ask you guys about this topic. This is a cheap alternative to get a cut piece of rubber (That could be worked with a cutter). But... These kind of thing leave a lot of questions about the methodology and the results. 1) What are the best results that you could get using a 3d printer which works with the closest material to rubber? Will it be cheap?. 2) During the process I noticed that the alcohol flow was constant in order to prevent the formation of those sticky ice particles, what about if you use an azotrope solution of alcohol (concentration greater than 98%) in order to use a smaller amount of that substance, just store it in a boil for few minutes and them extract the rubber piece to cut it. Just one advice... I am learning English and my knowledge wouldn't´t be perfect but the right/best way to pronounce "ALUMINIUM" is the British one :) I like your videos and please keep making such wonderful work. Hope your answer soon.
Chips definitely made their way down into the tank. My pickup tube was a few cm up from the bottom, and the chips sunk to the bottom pretty quickly, so I didn't have a problem with clogging at these low flow rates.
If I need some rubber material for a simple use with a specific form I cut out with the CNC a form and fill it with silicon. After cooling down you can use it. Works fast and is simple. Of course not for that many uses...
If you need simple 2D gasket shape, you can just use dragknife with your CNC (see donek tools dragknife + bCNC dragknife software). 3D gaskets can be probably cast using RTV silicone to some machined/3d printed mold.
Very cool problem solving! The only other method for cutting rubber that I can think of is laser or waterjet (there was definitely some booths cutting foam at IMTS). I suppose these methods can only profile though.
Hey.... lotta fun! Great video. Chilling rubber though, liquid Nitrogen. Dangerous and effective. Expensive and Dangerous. Um.. other than that.. It is Dangerous. But it works. I absolutely LOVE your Ice Vise!!! Talk about cool... Thanks for posting!!!!! Mark
6 лет назад
Very small bit plus very high speed and you can mill butil and other elastomers warm. You can actually melt and blow the cuts instead of cold cutting. I use a hand mill to shape rubber in various ways when I need oneoffs. Silicone rubber should mill fine too with this method. It's just that the bit must spin really fast and move x/y pretty slow.
I've had good luck recently 3D printing urethane elastomer, I made a gasket-like part on the makerbot at work (also printed some random squeezy toys too). The surface quality would probably be similar, but the dimensional accuracy might be a bit worse. Urethane isn't as suitable for some applications though. You can also laminate laser-cut sheet stock for some geometries. Have you ever tried cryocommunition of zinc or similar metals?
3D-printed gaskets sounds like an especially good use for 3D printing. With support material, it could be a really effective technique. I had to look up cryocomminution, which is just crushing/grinding? I haven't tried it. Would you use something like a ball mill with ceramic media for the crushing?
Applied Science a drop hammer is probably easier to build at home, but I think planetary ball mills are used commercially. I think metal media is less likely to shatter in a planetary mill, as long as it is still ductile at the temperature that the charge is brittle at.
Even for a one off I would mill something else to use as a mold for my part. Oogloo (made from more or less equal parts of silicone 1 and cornstarch and coloring) is wonderful stuff and casts very well.
Wow, great job! I wonder how it would work with a pour of liquid nitrogen? I like it because I once managed to turn some miniature rubber parts using a can of blow-off air duster, upside-down, so that the coolant comes out and you can direct the spray onto the work, freezing it long enough to machine. Small stuff only!
I saw that magnetic coupled pumps, that are BLDC driven, in a photo-developer machine. I was called upon to repair one, but it was not the pump, it was the flow sensor. So, if You are in a need for such a pumps, try find some photo film developer machines, there could be a couple of those (for every chem, one pump). Best regards
I am just curious how you decide where to go next from video to video. Is each topic part of a larger project you have going on at the moment or just maybe messing around with all your awesome equipment?
I remembered my father told me how he used liquid nitrogen to cool down a cylindrical silicon rubber and then grind it to level the surface.
10 лет назад
Very interesting, I would like to try it myself. Dry ice seems like a rather cheap and effective way to cool ethanol. However, obtaining a pump capable of reliably pumping this very cold ethanol seems like a more complicated problem. Do you have any advice regarding that? I have no idea what to look for or where to look for it...
Great video! Reminds me of a discussion on HKPro.com about cutting a variety of polymers to make replacement recoil buffers for an old pistol called the HK4. The guy making them has been using a CNC laser cutter (not sure, would this work on rubber?) and finds that with some polymers (polyurethane, for example) the material removed turns into a very sticky, greasy mess than is very difficult to remove. Somebody suggested freezing the PU first. Do you have any experience relevant to this?
Hi, love your videos. However have you tried a very high flow rate of coolant at the milling tip (contact area between tip and material) that would cool off any excess heat generated at the origin. This should make the material harder at that point and make it better for milling. I might be wrong but it sounds logical. Thanks
You say thats alcohol used to keep the cold temp? In my experience alcohol and many other liquids change rubber almost instantly. It becomes very hard to clean and reuse rubber seals for marijuana devices due to this. I noticed the rubber you have there has that all too familiar whiteish look to it that alcohol causes. Might want to try a different liquid.
Is there some kind of additive, which would make melted PE flow more easily, so it can be casted without use of press? I've found "diy machinable wax", which is PE dissolved in melted parrafine. You can easily cast it to blocks and machine. But it's still 80% wax. I wonder if this could be done 80% PE with some additive, so we don't loose the performance, but still can just heat the waste plastic and pour it without need for mechanic compression. That way i would be able to cast recycled plastic blocks for machining final parts rather than wax prototypes.
Interesting experiment! It looks like it is easier to machine a form out of aluminium and fill it with silicone or rubber under pressure instead. Even if I need one prototype - aluminium form method maybe even faster. Plus you can heat the form for vulcanization, make few copies using different materials ... What will be interesting is to try machining metals such as aluminium (like 6061) when it is cold to see if you get better surface finish. One would need to consider the expansion of metal when it heats back however. What if you take materials like ferrite cores and heat them up till they white and drop them into some salt solution chilled to -100C what properties can you get? What if you do same with two spinning copper cylinders at -100 and then squeeze white hot iron wire between them - will it form amorphous strip?
Hey! I need to supply liquid nitrogen instead of the super chilled alcohol, which pump is this which you are using? and where i can buy them? It would be a great help for me. Thanks in advance
I like to stamp out rubber parts with my press for nice clean cuts. think of a cookie cutter. You can form a die from sheet metal and use a shop press.
Liquid nitrogen would prolly do the same thing. I think the trick for that would be to keep the material in the tank in a basket until it was ready to be loaded into a semi precision holding device. I'd try it at high rpm for light layer rapid rpm and feedrate cuts.
"normally there pretty difficult to produce" Not really, if your company has access to a newer Objet/Stratasys machine. you can just use a FLX973 cartridge. Though i will admit SLA printing is not exactly cost effective.
battleminion Two-flute endmills are good for deep slotting on manual mills -- plunge down into the material, then move in one direction to make a slot. A four-flute endmill is more bulky and will prevent chips from being cleared from the slot, as well as jamming against the wall of the freshly-cut slot. Many CNC toolpaths are designed to minimize slotting by using a helical plunge path, and expanding perimeter cuts. There are also three-flute endmills, which provide a compromise between slotting capabilities and cutting speed.
Who else loves his 'bye' at the end? Great upload!
Senk Yoghurt u mean bah? Lol
/he's such a geek luv it!
I imagine he's insulting us at every opportunity. "C U Next Time"
I just want to sleep in your shop. I am in love with all your tools.
I like the sleeves up walk the walk, reading and seeing a process is one thing but trying it and doing it with any level of success it priceless. Cheers!
During the 1960's, I was in Graduate School The machinist used liquid Nitrogen to cool down Teflon rods to cut threads in the rod. This allowed a precision cut in the then slickest substance on Earth!
I think that it still is
Thanks Ben. Another construction technique for me to keep in mind.
This technique is probably not used as much anymore because there are plenty of options for making parts like this using a 3D Printer. The idea itself has a lot of merit, and it's great to see these types of manufacturing techniques demonstrated. Keep up the good work! Your videos are fascinating.
I wouldn't be so quick to write this off as an outdated technique; while filament extrusion printers have become incredibly common, you can't make anything but ABS or PLA parts. The great thing about this is that you can directly create complex one-off parts out of various elastic or soft materials with parts you basically have laying around, assuming you have a mill.
I think being able to make custom rubber parts is enough to give this technique worth. [Harder] plastic can only get you so far.
Additive machining may be a revolutionary process, but it isn't the end-all be-all of manufacturing processes. Mills and lathes aren't going to be going anywhere anytime soon.
Ryan Willis You could possibly print parts like this on an extrusion type 3D printer using a thermoplastic elastomer filament like Filaflex or Orbi-Tech TPE.
While we are on the subject of filament materials, there are others too, like filaments based on nylon, High impact polystyrene(HIPS), polyvinyl alcohol(PVA) and polyethylene terephthalate(PET), polymer composites containing carbon fibers, wood dust, chalk etc, and filaments for printing foam/porous rubber(Basically TPE particulates in a PVA filament, the PVA is washed out with hot water or a suitable solvent after printing, leaving a porous object made from a TPE). Other 3D printing processes can handle other materials too,
However, I agree that 3D printing is just another tool, not the ultimate production process, there will always be other processes that may be better on some things, though 3D printing may still play a part as a step in a more traditional process, you can 3D print a model for making molds for casting, for example.
For the price of a good 3D printer, you can have an excellent milling machine and the capabilities to machine everything known to man(almost). Plus you can make gears on some milling machines, new bedstocks for the same machine, pulleys, everything a lathe can do as well as flat surfaces.
Lathes can't make themselves, milling machines can.
Wicked cool. No pun intended at all.
Seriously, I love your channel so much. You touch on everything interesting, never anything boring and explain the science in a way that anyone could understand. So glad I stumbled cross your page months ago :3
Very nice use of the savant chiller. Thanks for your efforts.
Enjoyable as always! I'm always learning stuff when I watch your videos.
I was working on a project that needed custom boots. I found some tie rod end boots that almost worked, but the smaller hole was too small. However, remembering this video, I used some liquid CO2 to cool the boot down, allowing me to use a very bi to drill out the hole. Thanks for sharing your ideas and making these great videos.
If you are interested, I did make a video on what I did: ruclips.net/video/hZKY56i-D34/видео.html
Holy shit dude, you always produce the best videos.
Very interesting setup. At the research lab I worked in at university (as a lowly undergrad ) one grad student needed to drill 12" long holes in a block of neoprene. I think the mechanical engineer who ran the lab knew about this method. He poured liquid Nitrogen on the neoprene as the cutter went through it. They used a 3/8" Dia. steel tube that had one end sharpened. They got good results. The holes through the neoprene were for simulating blood vessels. Not sure how that experiment turned out.
I always enjoy watching your videos...keep up the good work
Very clever! What a "cool" technique!
I want to thank you for yet another inspiring video.
Surprised no one has developed an open source head hardware and software for a CNC to cut like a Cricut or Zund cnc knife cutters. Never seen this before. Interesting and thanks for sharing!
Hi, Ben. I'd give your ice-vice technique another try with internal passages in the alu plate: water the plate and place your rubber stock onto the plate, run the coolant thru the plate and get it cold. Apparently, this won't work that well with thick rubber pieces, but I'd expect it to perform rather well with something similar to what you've shown. And no more stickin clamps!
Just after 5 seconds I knew this video is worth a thumbs up.
Very nice, silicone(and neoprene) just got a lot more useful!
Also I think Machinable ice could be really handy for lost casting cooler materials, rather than firing a lost wax ceramic mold for metals. Do you think there is a good dissolvent that would make it machine better when frozen? Might be worth playing around with
I'm curious to know what tolerances you were looking to achieve in milling the chilled rubber? As a fitter & turner specializing in plastics injection mold making every dimension required a nominal shrinkage rate added to the finished product size - to compensate for plastic shrinkage as it shrank from 200+ degrees C. to room temperature. We used shrinkage rates of anywhere from 1.02% to 1.2%.
So did you have to calculate any subsequent machining 'shrinkages' to compensate for the chilling of the rubber?
I think that more simple way is cutting some test detail and just measure what it be.
Depends on the material, exactly how much any given material varies from another I wouldn't know. 'Coefficient of thermal expansion' should be a useful search term, otherwise, as previously mentioned, 'guess and check' methodology might be possible.
Very cool process you came up with there! With setup technicality's aside, really simple concept! That may be pretty useful some day!
Ben, with your hobbies you are remarkably busy and you know no limits. I would ask which tendency came first if it weren't pointless; thanks for sharing
Thanks! I sometimes feel guilty after spending a chunk of time doing "nothing" ie reading on the internet or similar activities that have no observable output. It's a nice personality feature to have when productivity counts, but has its problems as well.
really interesting never imagined that i could mill rubber by freezing it.
Very neat. Thanks for sharing. How much does the material shrink when it's cooled, and did you have to account for the shrinkage when milling the part?
In my Physisc Institute in Torun (Poland) since 70' rubber is machined using liquid nitrogen. Of course there wasn't CNC, but this method gives very precise parts. We made liquid nitrogen in our condensing unit so it was very cheap method of chilling.
Fascinating! All your vids are great! :)
This is very interesting. I think they make CNC tools with holes in the tool to flow LN2 through the head. It also might be better to set up a open tray and CNC the part in a bath of LN2. Using ice to stick it down is brilliant. For neoprene because it is permeable putting it in a pressure cooker for a few minutes might work well. The water saturated part when frozen should cut like frozen butter.
That is it!, As a fitter and turner I hereby declare you a wizard!
I have cut nonfrozen rubber on a lathe using very high rake, almost knife-like cutting tools made of high-speed steel with generous relief angles on all too; surfaces at rather high speeds that I thought kept the rubber against the tool with centrifugal force. I used an oil-in-water flood lubricant that made it cut much better. I expect the water, not the oil, helped the cutting. I arrived at the method through desperation. I would have used your method of dry ice and alcohol had I known of it.
Great thanks a lot. Now next best thing is to use a rubber resin and print it in SLA printer or 3D printed mold and silicon rubber. If we want a specific rubber material your method would be the best.
I have made hundreds of complex close tolerance soft rubber parts for the submarine industry using conventional Dremel grinding wheels and a high speed spindle (in a Lathe OR Mill). You just need to think outside the box. Trust me, try it
Sparey's The Amateur's Lathe, suggests that rubber can be cut on a manual lathe using stanley knife blades.
Something akin to a flycutter might work well for "milling"
A little tip for the pump. A little peristaltic pump using silicone tubing will solve some of your problems, just the flow rate could be to small. I make them usually from 5mm-MDF if it needs to be cheap (coping saw and drill press). Lasercut acrylics if I have some more budget on a project.
That's a neat way to deal with needing rubber parts in a hurry, and in low quantities. Have you done this long enough to get a sense of how the tooling holds up at low temp? I could imagine the tool chipping if the rubber got hard enough...
If you're interested in this kind of thing, you should research Intraocular Lenses (used in cataract surgery). The state of the art material that is used in these lenses is a soft acrylic (harder than the neoprene shown here, but still pretty soft). The most common way that these are made is by cryo lathing the lenses. The optic diameter is about 6mm in diameter, and using the cryo lathing process, you can cut a near optic quality surface.
I cut rubber on a lathe in my apprenticeship. We did it by grinding custom HSS cutters with a very high rake angle.
I found this very interesting, thanks for sharing!
THAT IS MY SALVATION!
For years I tortured myslef by using liquid nitrogen to freze the rubber. This gave me little time for machining!
And I see this video after it is 8 years online!
I glued a piece of aluminum to another piece of aluminum with orange silicone RTV and then chilled it down with liquid nitrogen and tapped it with a hammer. It broke right off. So there is a temperature where silicone will get cold enough that you could cut it, but it may be too brittle to survive.
When I need to cut rubber I always use diamond grinding bits at high speed and the finishing surface is great!
OUTSTANDING WORK! My only question is why didn't you use antifreeze??? it seem to me cheaper..
Very very cool stuff!
Another method, at least if you're dealing with things like these and you happen to have a laser cutter, well, you can see where I'm going. Only downside to that is that it's a very dirty process, creates a lot of blackened particles everywhere which needs to be vigorously scrubbed off.
What would you think about building a liquid cooled plate, basically running coolant through channels cut through the plate to supercool it. Maybe it's a bit like the ice vise you talk about, and I don't know if it would get cold enough to chill the rubber properly, but food for thought at least.
Cheers!
I have borrowed and used a cold gun while milling hardened material with a tungsten carbide end mill. I am an apprentice toolmaker so I have only 10 months experience machining. So I think the tool steel was cooled way better than using liquid coolant. Doing some research I found out they are easy to build and can draw temperatures to freezing point. Maybe you can freeze the rubber using a cold gun. Sounds like a future project. No?
I make some parts that are essentially Tygon tubing (64 Shore A) with countersunk (internal chamfered) ends. They should be injection molded, but the short run manufacturing is too low a volume to justify molding. I put them in the freezer in the kitchen. I manufacture them in batches of 20 at a time. Any more than that and they thaw in the summer and the cut quality is bad.
I enjoyed seeing your dry ice and alcohol machining technique. Thanks!
I had previously considered a small Styrofoam box with dry ice, but the freezer compartment of my fridge is good enough for my needs. If I'm in a hurry, I'll sometimes dunk the parts in ice water to facilitate the heat transfer and machine them a bit wet.
Venezuelan 17 years boy over here. I have a couple of questions that I would like to ask you guys about this topic. This is a cheap alternative to get a cut piece of rubber (That could be worked with a cutter). But... These kind of thing leave a lot of questions about the methodology and the results.
1) What are the best results that you could get using a 3d printer which works with the closest material to rubber? Will it be cheap?.
2) During the process I noticed that the alcohol flow was constant in order to prevent the formation of those sticky ice particles, what about if you use an azotrope solution of alcohol (concentration greater than 98%) in order to use a smaller amount of that substance, just store it in a boil for few minutes and them extract the rubber piece to cut it.
Just one advice... I am learning English and my knowledge wouldn't´t be perfect but the right/best way to pronounce "ALUMINIUM" is the British one :) I like your videos and please keep making such wonderful work. Hope your answer soon.
chavo comprate un cortador lase chino de 100w CO2 y puedes cortar hasta 1/4 de espesor
ben your videos are very informative to us. thanks for your effort. i like your workshop toooo :-)
Ben! revisit this with an ultrasonic knife! just get you one of those transducers that go in ultrasonic cleaners!
Did you have issues with chips getting into the tank or pump? Or did you have a filter or it just wasn't an issue? Thanks for the video :-)
Chips definitely made their way down into the tank. My pickup tube was a few cm up from the bottom, and the chips sunk to the bottom pretty quickly, so I didn't have a problem with clogging at these low flow rates.
Applied Science Gotcha, thanks for the reply.
That is so cool and really simple ! Just freeze the soft material
If I need some rubber material for a simple use with a specific form I cut out with the CNC a form and fill it with silicon. After cooling down you can use it. Works fast and is simple. Of course not for that many uses...
You can do this really easily in a laser cutter, obviously you should choose rubber that is not too toxic to burn.
If you need simple 2D gasket shape, you can just use dragknife with your CNC (see donek tools dragknife + bCNC dragknife software). 3D gaskets can be probably cast using RTV silicone to some machined/3d printed mold.
Try single flute up-cut bit. And the rubber has to be in duromer of no more than 60-65ShA.
wow, great video.
keep up the great work!
Very cool problem solving! The only other method for cutting rubber that I can think of is laser or waterjet (there was definitely some booths cutting foam at IMTS). I suppose these methods can only profile though.
Hey.... lotta fun!
Great video.
Chilling rubber though, liquid Nitrogen. Dangerous and effective. Expensive and Dangerous. Um.. other than that..
It is Dangerous. But it works.
I absolutely LOVE your Ice Vise!!! Talk about cool...
Thanks for posting!!!!!
Mark
Very small bit plus very high speed and you can mill butil and other elastomers warm. You can actually melt and blow the cuts instead of cold cutting. I use a hand mill to shape rubber in various ways when I need oneoffs. Silicone rubber should mill fine too with this method. It's just that the bit must spin really fast and move x/y pretty slow.
I've had good luck recently 3D printing urethane elastomer, I made a gasket-like part on the makerbot at work (also printed some random squeezy toys too). The surface quality would probably be similar, but the dimensional accuracy might be a bit worse. Urethane isn't as suitable for some applications though. You can also laminate laser-cut sheet stock for some geometries.
Have you ever tried cryocommunition of zinc or similar metals?
3D-printed gaskets sounds like an especially good use for 3D printing. With support material, it could be a really effective technique. I had to look up cryocomminution, which is just crushing/grinding? I haven't tried it. Would you use something like a ball mill with ceramic media for the crushing?
Applied Science
a drop hammer is probably easier to build at home, but I think planetary ball mills are used commercially. I think metal media is less likely to shatter in a planetary mill, as long as it is still ductile at the temperature that the charge is brittle at.
Cool. I stayed up all night working on that joke :)
Nice video, thank you. I wonder if a vacuum table would work to hold the part?
Even for a one off I would mill something else to use as a mold for my part. Oogloo (made from more or less equal parts of silicone 1 and cornstarch and coloring) is wonderful stuff and casts very well.
Wow, great job! I wonder how it would work with a pour of liquid nitrogen? I like it because I once managed to turn some miniature rubber parts using a can of blow-off air duster, upside-down, so that the coolant comes out and you can direct the spray onto the work, freezing it long enough to machine. Small stuff only!
I saw that magnetic coupled pumps, that are BLDC driven, in a photo-developer machine. I was called upon to repair one, but it was not the pump, it was the flow sensor. So, if You are in a need for such a pumps, try find some photo film developer machines, there could be a couple of those (for every chem, one pump).
Best regards
Is this still a viable option? I think 3d printing has gotten cheap enough to just print the desired parts in TPU/Nylon
Very interesting. Did you experiment with different cutter speeds?
Being from Alaska, I can say there are simpler setups. Lol
Nice work, thank you.
I am just curious how you decide where to go next from video to video. Is each topic part of a larger project you have going on at the moment or just maybe messing around with all your awesome equipment?
I remembered my father told me how he used liquid nitrogen to cool down a cylindrical silicon rubber and then grind it to level the surface.
Very interesting, I would like to try it myself. Dry ice seems like a rather cheap and effective way to cool ethanol. However, obtaining a pump capable of reliably pumping this very cold ethanol seems like a more complicated problem. Do you have any advice regarding that? I have no idea what to look for or where to look for it...
Very informative! Thanks!
Great video! Reminds me of a discussion on HKPro.com about cutting a variety of polymers to make replacement recoil buffers for an old pistol called the HK4. The guy making them has been using a CNC laser cutter (not sure, would this work on rubber?) and finds that with some polymers (polyurethane, for example) the material removed turns into a very sticky, greasy mess than is very difficult to remove. Somebody suggested freezing the PU first. Do you have any experience relevant to this?
Very cool. I wonder if 3d printing might be a better way to go.
How did you filter the rubber bits out of the alcohol? Did you use a screen filter or something else?
Hi, love your videos. However have you tried a very high flow rate of coolant at the milling tip (contact area between tip and material) that would cool off any excess heat generated at the origin. This should make the material harder at that point and make it better for milling. I might be wrong but it sounds logical. Thanks
Do you think a vacuum hold with a special setup to divert alcohol away from the pump would work?
You say thats alcohol used to keep the cold temp? In my experience alcohol and many other liquids change rubber almost instantly. It becomes very hard to clean and reuse rubber seals for marijuana devices due to this. I noticed the rubber you have there has that all too familiar whiteish look to it that alcohol causes. Might want to try a different liquid.
I was thinking of dunking a solid rubber stopper in liquid nitrogen and then trying to quickly drill a hole in it. I wonder if that will work.
It seems that energy of vibrating cutting tool helps ice to melt and dusolve in alcohol, so rubber unstick that fast.
Like a [Bridgeport] BOSS! ;-)
They even do that to bore tunnels through ground with high groundwater level I think.
Shouldn't it help to put a peltier element undes the workpiece? Maybe it would even keep the ice in place longer.
Is there some kind of additive, which would make melted PE flow more
easily, so it can be casted without use of press? I've found "diy
machinable wax", which is PE dissolved in melted parrafine. You can
easily cast it to blocks and machine. But it's still 80% wax. I wonder
if this could be done 80% PE with some additive, so we don't loose the
performance, but still can just heat the waste plastic and pour it without
need for mechanic compression. That way i would be able to cast recycled
plastic blocks for machining final parts rather than wax prototypes.
This would be awesome for making rubber seals that are no longer available for my antique car.
Hello Aplied Science, would you say that making a cryogenic freezer is within a home gamer's reach?
Interesting experiment! It looks like it is easier to machine a form out of aluminium and fill it with silicone or rubber under pressure instead. Even if I need one prototype - aluminium form method maybe even faster. Plus you can heat the form for vulcanization, make few copies using different materials ...
What will be interesting is to try machining metals such as aluminium (like 6061) when it is cold to see if you get better surface finish. One would need to consider the expansion of metal when it heats back however.
What if you take materials like ferrite cores and heat them up till they white and drop them into some salt solution chilled to -100C what properties can you get? What if you do same with two spinning copper cylinders at -100 and then squeeze white hot iron wire between them - will it form amorphous strip?
What about using laser cutting perhaps combined with this cooling technique?
Hey! I need to supply liquid nitrogen instead of the super chilled alcohol, which pump is this which you are using? and where i can buy them? It would be a great help for me. Thanks in advance
SOOOO Coooool ! ! (no pun intended !)
Awesome!
total genious!
Would it be accurate to say that even below 0C, ice dissolves in liquid alcohol?
I like to stamp out rubber parts with my press for nice clean cuts. think of a cookie cutter. You can form a die from sheet metal and use a shop press.
Would double back tape hold it down?
Liquid nitrogen would prolly do the same thing. I think the trick for that would be to keep the material in the tank in a basket until it was ready to be loaded into a semi precision holding device. I'd try it at high rpm for light layer rapid rpm and feedrate cuts.
perhaps you could make a cold plate by drilling coolant passages through a block of Al and then drill small holes to make a vacuum holddown.
Will it works with liquid nitrogen?
"normally there pretty difficult to produce" Not really, if your company has access to a newer Objet/Stratasys machine. you can just use a FLX973 cartridge. Though i will admit SLA printing is not exactly cost effective.
What type of alcohol do you recommend for this setup?
Nice info, very usefull , do you use 2 or 4 flutes in the end mill?
battleminion Two-flute endmills are good for deep slotting on manual mills -- plunge down into the material, then move in one direction to make a slot. A four-flute endmill is more bulky and will prevent chips from being cleared from the slot, as well as jamming against the wall of the freshly-cut slot. Many CNC toolpaths are designed to minimize slotting by using a helical plunge path, and expanding perimeter cuts. There are also three-flute endmills, which provide a compromise between slotting capabilities and cutting speed.
Oh thanks, I will try to make some test if i find a old chiller for freazing the alcohol Thanks
Why not use heat to cut out a gasket?