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Do Draft Shields Prevent Warping?
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- Опубликовано: 1 апр 2022
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In today's video we take a look at warping and draft shields. I have known of draft shields for quite some time but was never convinced that they did much. Printing ABS in on an unenclosed printer we will use a thermal camera to see if they are able to maintain heat. We will go over how to set them up in Cura and take a look at the results.
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The best way to stop warping on abs I have found is using gcode to keep the bed from cooling down so fast. I have my bed go from 110 to 80 and hold the temp for a few minutes after the print is done so the bed cools down slower.
That sounds like a good idea could even go down in stages, like a reverse cooling fan spread.
@Aaron Morrow I use simplify3d and can it do using it now that now. I may give it a try.
One note about the thermal camera use - Part of the temp reading of the bed is reflected ir from other objects. The bed temp where the plastic is is not actually hotter. You can see this really well on video when the hot end moves and you can see the bed temp "change" with the movement of the hotend.
I use draft shields for anything that warps or has cracking. So ASA, ABS, Nylon. It works very well and allows me to print functional parts with an open printer. I also feel the print quality is a bit better as it spends some time printing the draft shield, so layers with low cross section area print just as good as the rest of the part. Definitely recommend to always use them for materials that require enclosures. I wouldn't mind seeing someone evaluate draft shields within enclosure...
I am curious what size the prints are where shield is effective enough. Do you have some experience to share regarding this? If so, tnx :)
A little brim has always work for me for ASA or ABS, I don't see the advantage of that shield, particularly when you have to print high pieces.
@@mr.nobody8174 late reply. I have printed abs parts that are 4 inches tall on a bed slinger w draft shield that succeed where they split otherwise.
@@Turbo999be less and more unform cooling. Might make a part that just fails become a part that just succeeds. Maybe I'll grab a thermal camera and do a heads up comparison to see if that's true :)
Working Great here, Open Air Sidewinder X1, BIQU SSS bed working no additives, Draft Sheild, 30s Layer Time, 240 Extruder, 100 Bed, 10mm part and shield spacing, 10% fan (5015 duct), got a really nice voron test cube with Polymaker ABS, THANK YOU FOR THE VIDEOS!
Great vid! I have only used draft shields on "short" parts that tend to lift. I've had better success adding "mouse ears" on those parts but draft shields are my go-to for when "mouse ears" aren't an option.
Daniel, I really loved the Thermal Camera comparison. I suspected it would not be negligible: a couple of months ago I fought a severe ABS warping on one piece and what saved me after hours of frustration was the Draft Shield. PS: I have an enclosed Ender… but the geometry of that part “invited” warping (when the base is much smaller and it widens as it goes up). Love your content.
Really great to see your scientific approach. High quality video!
I have been using a skirt as a draft shield . I have found that i needed it very close to the perimeter of the part to be effective. I still needed to pull all the other measures to get abs to work as well hiwever.
Thanks again!
People question the effectiveness of a draft shield because hot air rises, but this is only true when cold air can flow in to replace it. A draft shield limits the entry of cold air which will cool the parts. The only way in is down past the head and this is normally another hot area. It'd be interesting to try a smoke test to see where the air flows are. (Maybe even a small hole in the plate and pump some smoke up into behind the shield, special raft maybe).
I've been printing ABS in a much colder room (about 12 degrees C today) and without an enclosure I get warping that will rip the item off mid-print, or snap the layers apart, or both. After much tinkering, the three things I did that gave me working prints every time were: 1/ Covering the whole thing in a garbage bag for a makeshift enclosure. 2/ Adding draft shields to my prints. 3/ Leaving the finished print on the fully heated bed for an hour for any internal stresses to dissipate.
Great detective work. I’m always curious how things work and I, too, have never used one before. I'm going to keep it in mind now for the future. Great video!
I have used draft shields on ABS and a tried on PETG. If my PETG is dry it seems to work OK without the draft shield, but it really helped on ABS. It would be interesting to see some tests with different bed temps to see how they impact warping. I remember seeing somewhere that keeping the bed temp and the hot end temp as close as possible would help.
super interesting video! I was wondering how much effect this would have. I think when I have issues with this I'll try to use a printer with an enclosure to get rid of that problem, but always good to know
Yes it definitely works. Living in upstate NY printing in my basement the ambient temp is so much lower and unless I use a draft shield corners curl up
My central air blows right on the machines at 72°F. Doesn't affect the print quality. I do print in PETG most of the time. Honestly, I only get stringing when I do clean time-lapse video because it has to move the print head to the corner and bed out to take the snapshot. If I don't do a clean time-lapse or time-lapse at all it doesn't string because it doesn't have to move the print head out of the way. I would also suggest that you put your printer in the corner of the room. That will give it two walls to block drafts.
drafts shields are great when you can't use cooling fan to give time for the previous layer to cool without having to print slower and alter the flow on that smaller section
Call it nitpicking but wouldn't it make more sense to use a print that *did* warp without a shield to see if it helps or not in practice? Or use a different title, I don't know.
I've been printing with ABS and nylon for a while now. No, draft shields will not prevent warping. I had to change to a hotend that doesn't blow air down on the part, and even then, I still had problems with sharp corners and overhangs curling up into the nozzle.
I've had the same experience.. on small parts, a draft shield can work but for anything larger than 100mm, I've had warping even with a draft shield. Covering the whole printer with a clear trash bag has worked better for me.
I switched back to an older 20mm fan for the hotend, and turned it around to pull air off rather than push air. The 20mm fans have a much higher velocity when compared to the larger 30 and 40mm versions most of us switch to. I use a Dragon v2 (HF Model) for the hotend [a lot more open area than your average e3dv6/clone]. This stopped the odd bit of extra draft i was getting on my ABS parts. Not sure if you can, but id give that a shot to add to your progress.
@@Fukgoogle123 I've actually had good results with a "draw through" setup on the V6 hotends using 5015 centrifugal fan.
@@Adam-ht9jn Good to know! Ill have to experiment sometime and see if there is even a noticeable difference between the hotends when setting them up this way. I know the draw thru isnt the norm, but (like here) it really makes sense at times to do it and see what helps/hinders.
I'm planning to try this when I do some experiments with ASA on an open bed printer. I think "Draft Shield" doesn't really explain what it's actually doing in your tests though. Yes, if there was a draught in the room, it would help shield it from that somewhat, but even in a room with perfectly still air it has another effect - it helps reduce heat loss from the part via infrared re-radiation.
If you imagine yourself being the print job and you look around your field of view 360 degrees in 3d dimensions a large part of what you can "see" is the walls of your room which are "cold" compared to the print bed, so there as a lot of heat loss. As well as direct conduction there is a lot of IR radiation coming from the heated bed and not much from the upper 180 degree field of view to the part which is mostly your room.
The printed draft shield forms a wall around the part which is at a much higher temperature than your room walls - the printed wall is heated both from conduction directly from the bed, (which probably won't go very high due to the thinness of the wall) but also from IR radiation from the bed surface radiating to the wall at an angle, warming the wall. The wall then re-radiates this heat back at the part to some degree.
Increasing the spacing between the part and the draft shield should actually increase this effect somewhat as you would be increasing the bed surface area between the part and the draft shield which is able to heat the inside of the shield with direct IR radiation. So don't make the gap between the part and the shield too narrow. Of course the outside of the shield is also being heated by IR radiation from the outer parts of the bed and due to it being thin this heat will be conducted through, so the larger the bed relative the print job the better.
This is all similar to what happens to a car parked on a driveway on a winter night - if the sky is clear the IR "temperature" of the night sky is extremely low so there is a lot of heat loss from the car depending on how much of the sky is visible to the car, causing the windows to ice up and go below ambient air temperature. But a cloudy sky raises the IR "temperature" of the sky dramatically and dramatically reduces the heat loss from the car even for the same air temperature resulting in the windows probably not icing up.
I print in an enclosure so it's controlled temp. but still need a draft shield for most things I print because of the size, usually over 4" on any direction. For enclosures, we also practice putting slots in to reduce the tension a line puts on the lines underneath it, if the customer allows it! Helps significantly.
As a European, I'm glad 3d printing is about almost exclusive metric values. Therefore I had to lookup what "the mid seventies" was in Celsius ;)
Thanks for this, but if you mix temperature scales, could you please explain what that is in both scales? I guess most of you Fahrenheit junkies are getting used to Celsius through 3d printing or science in general. The rest of the wold still uses Celsius ;)
great video bud, i have had some issues with PETG warping on me so i might try this. thanks for what you do!!!
Yeah for low profile prints in ABS I do use draft shields and I also made a video about them some years ago, they do help a lot and keep the heat inside
thanks for the info. i've had abs hanging around for several years not being used because i hadn't built a chamber. decided to test the shield and after figuring out the z offset for abs it's printing great.
I print ABS with the same Z as PLA and it's never been a problem. Prusa MK3S+ by the way.
I did not know this was a thing. I have a spool of ABS, but I've never tried printing anything with it yet. I'm going to give this a go and see what happens. Thx!
I use a skirt that runs up just 3 layers tall as a psuedo draft shield. What it solves for me is that I print in a finished room in a garage and it does get cold enough for snow, ice and sometimes things you don't expect to freeze. While the room is kept 65F to 70F, opening and closing the door blast a breeze right across the print bed. I have had that cause sharp corners to lift off the bed right in front of my eyes, doesn't happen with the psuedo draft shield.
6:40 You should have printed a draft shield for your draft shield.
I've been trying to make some prints with asa and these draft shields seem to work decently, now I gotta find why the damn filament doesn't stick to the plate.
A draft shield seems like something of a no-brainer when you need to keep the temperature of the part even and high. My printer is in a separate larger enclosure, but not so small that it will manage to heat the space meaningfully - some 5 degrees over ambient perhaps. But with draft shields, I think I'll give some ASA parts a whirl.
I would like to see the flir used to show an enclosure doors open vs shut or some way to compare open air to enclosure to draft shield.
It is called an ooze shield in Simplify3d and I found it to just create more failure points as shown in your video where it could itself warp off the bed and then could collide with the extruder! It will also waste time, money and material! I just throw a plastic bag over my printer and turn up the bed heat a bit to create an ad hoc heat chamber!
How about a reusable draft shield. Could be an accordion sleeve, thin tpu or even tinfoil with a stings tied to z bar that rises as z goes up:) or thin legs that go up and over z wide enough to avoid X interference.
the new prusa xl has an addon for that iirc.
just put a clear trash bag over the printer.. much cheaper and easier.
Did you test with it using a wider / flat part that tends to curl up during printing? We print a lot with ASA on open frame printers but its a draft-free 75 degree room at all times. The parts are about 1 inch wide and 3 inches tall. They are engineering-grade parts for an industrial application that see real world use. We have never had to replace any of them in 3 years.
funny, I almost exclusively print in ABS and even with about the cheapest available printer atm and no enclosure.. a 110°C start temp for the bed (1-3layers usually) and then dropping to 105°C at first than 100°C maybe; depending on the height and print time and successfully so I need to point out. The only time I experience warping is when I carelessly forgot to keep my glassbed perfectly clean (the silver ABS [BASF] somehow leaves a waxy residue after a print.. and that doesn't stick well so a quick IPA wipe before each print and I'm good. (and when IPA is out a good soap and water wash)
But true I usually print up to 15°C above the filament manufacturers recommendation (currently @250 for a recommendation of 225-245°C.. so yeah just 5 over atm)
and don't use draft shields at all (tried once, no difference in result.. saved time removing it from then on)
Oh I almost told a lie.... I can't print too well on that cheap i3 clone if the footprint is too big (say above 120mm in X and/or Y) since my bed isn't heating up very evenly (I did mention it's cheap, right?) I get a deviation of around 10°C from the center to the edges, so on those parts I actually tend to add a draft shield again, but just to help the bed keep the temp uniform more easily.
And sometimes that doesn't even help. I just found out about the tight enclosure (from 2015 doh!) whilst reading about the ribbed vault infill since I didn't like the cura implementation too much for some reason ... long story short.. IceSL was installed a few moments ago.. giving that tight encloure draft shield a test soon.
Wondering if they will help with nylon.....
Perhaps it's possible for a draft shield to be set to have foot holes to help against elephants foot?
I think testing with the FLIR is much much more visable if you do an object which has a bigger opening in the object itself
Very interesting I didn’t know you could do that thank you for sharing
How well would a simple cardboard shield around the printer, open on top, work to do the same thing?
I printed abs in my Ender 6 without a top on it and it usually works but the fumes are terrible
great share. thanks
Great video! I looked at draft shield but I on print ABS in an enclosure. Now for the tough question. What causes that fat layer at about 15mm? I get those once in a while but have no idea where to start looking to cure the problem.
Do you have cooling fan changes around that area?
I believe it is due to the warping/temperature fluctuating. Since it was much more noticeable on the square I printed without a draft shield the only thing I can think of is that part of the model is cooling causing the part to warp. With the second part not having any changes but that draft shield to help keep heat more even the bulge is almost completely gone.
When you get that issue is it with ABS specifically?
@@ModBotArmy It doesn’t happen very often, it’s just irritating when it does. Doesn’t appear to be height specific and I’ve had it happen with all filaments. Since I’ve been doing most of my printing on the Voron 2.4 I don’t remember it happening. Mostly on the Ender3v2. I just assumed it was something binding in the Z axis. When I saw it on your print I just thought I’d ask. Could be a fat section of filament I guess.
@@woodwaker1 Nope. No cooling fan changes.
just build an enclosure if you Print with materials that warp , thats what i did for my abs
I didn't know ABS warped. I print it at 235-250° with the bed at 110° door closed and the hatch on and closes. 20% cooling and circulation fans off.
How do you del with the carcinogens and toxins getting released when printing with ABS and PETG without enclosures and inside your home?
Stupid question. Do you have the nozle fan (s) on or off?
Thanks
The side-by-side thermal comparison is misleading as FLIR cameras display a range of temp and there is no way that your part is as warm as the nozzle.
Left side has the nozzle in shot, therefore it’s the warmest (whitest) area of the screen whereas the right side does not and therefore shows the base of the print as the warmest (whitest) area of the shot.
You will need to maintain the same camera angle for an accurate comparison.
What would you recommend for a first time 3d printer?
Good video, maybe a 4 sided painters tape wall would work, folding 3” tape in half with 1/4” of edges tape secured upright to bed.
It’s gonna be hard to put .2mm of tape on every time the z hood. Lol
I've had much success with ABS + Brim + Draft shield on an open Ender 3 V2. I've upgraded the bed with a textured powder coated PEI and I use no adhesives at all.
And I've managed to print a lot of ABS, mostly without any warping and sometimes with just minor warping on corners. I recommend the shield for ABS for anyone who hasn't built/bought an enclosure
Thank you, very nice video!
Great video as always
Great to see the temp. gradient influence on the print
Thanks for sharing your growing knowledge with all of us 🙂
It was a fun experiment and nice to see that it can actually influence the temperature around your part. Thanks for watching :)
Good video. :) Haven't used draft shields before, but it's interesting.
I tried the draft shield and it warped lol, so I turned it off and I just stuck with a brim.
Interesting.. going to have to look at this
Definitely worth taking a look at. I think at least knowing of the tools in the slicer is super useful even if they are not needed all the time.
great video, thanks! draft shields would appear to be rather inefficient without a lid as most of the warmth would move up.
so, fitting a thin plate around the hotend that serves as a moving lid combined with a draft shield should be a different story. Anybody tried that?
Sounds good. I will try that in the next days
nice work. I am not familiar with Flir but did you use the same temperature scale for both cases? my infrared camera does not fix the scale and thus can't compare based on color only.
He did mention that he fixed the scale. Weird that an IR camera wouldn't allow that, something I'll have to keep in mind if I need to get one!
Thr temperature scale should have been set to fixed 30-130°C to better show the changes in part temperature
I believe my thinking behind having the wider range was that it would be able to see the filament coming from the hotend. In this case you are probably right since the primary focus was on the part temp that would have been within the lower range.
does this help with non heated beds?
Great work 😀
The bed should always be below glass transition temperature to ensure rigidity of the base layer
Looks like the glass transition in most TDS I am seeing is 105. The bed didnt climb above 100C. It was set to 100C but I doubt it actually reached that on the top surface especially with it being open.
I printed my Voron 2.4 parts in ABS, ASA and, hardest of all, Polycarbonate on my Prusa MK2.5. I found draft shields definitely helped and the PC would not have been possible without using them. Of course, it means you need to print each part individually but, as I was waiting weeks for all the bits to arrive from China, I had the time to print them carefully.
Still the best 3D printing content on your channel - thanks mate.
Thank you very much :)
Draft shields used to be all the rage back when folks could only print tiny things realistically and nobody had a legitimate reason to stick their printers into enclosures, the cons of overheating electronics/motors and thermal runaway etc, just made all that a very poor idea back then, now it's fairly mainstream. Hence I find it funny you mention draft shields being uncommon, it's one of those. "what's old is new" moments. Also very curious they are under 'experimental' also if you've seen the filament printers that can print upside down, the draft shield works even better on those because the heat rises up into the part and stays at the base.
I wish you would stream on twitch again
I made 12 and still end up at Colonia 12x a year.
I would really like to know what kind of a pegboard is there in the background... 🤔🤓
It is Skadis from Ikea :)
@@ModBotArmy the color misled me 😅 Thanks 😊
for very small parts... yes... but anything larger... usually do not have much of an effect in preventing warping....
Repeat the test with an object that is long and flat and I think you will have different results.
You should switch to using only Celsius only. It’s confusing when you say 70 ambient and your heat cam says 40. It’s easy to switch, just hit the c button on your thermostat and phone weather app and never look back 😃
I think a draft shield would be better on a duel extruder. Use a cheap easy bed adhesive pla for the shield.
not really... the time needed to switch between the nozzles or materials are simply not worth it. also PLA will lose some of the adhesion when the bed is warmer than 60C so if you print ABS and PLA at the same time, you will experience issues with the bed adhesion issues with PLA.
If you use a draft shield, I'd suggest printing upside-down (I mean the whole printer). Heat rises and the shield will keep it in.
The first 30 seconds of your video is pretty weird I thought "either this channel is for complete beginners or he completely takes his audience for beginners" then when you go on it's clear the content is quality.
Don't take your audience like if they don't know fdm if your content is more advanced
I try to be as inclusive as possible which is tough to juggle. Many that do watch my channel are beginners as well so I try to sort of lead into it by breaking some of it down. If I don’t include that I end up getting questions in the comments. I am always working on refining my content and style and appreciate the feedback.
Use petg. Much better than ABS in all ways
"Without further ado" Oh dear.
No can do ❤️