Polycarbonate build plate…. No bed heat Success!!!
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Hi there,
First of all, big big thanks to Whitewolf for letting us know this… I'm at a really early stage, but so far, this material looks awesome.
Yesterday I sanded one of the sheets I bought (the transparent one) with a 80gr sand paper to start with, and with a 120gr after, it was really easy (I've recorded a video, and I will post it with a timelapse of one print I did last night) and only took around 10 minutes, then I washed it, and gave another try with the 120gr sand paper, whased it again, and cleaned with alcohol.
I tried it with PETG, a material I had problems printing with, even with heated bed (around 70 degrees) and blue painter, as it usually warped in the corners... I had more success with my black Buildtak, although removing the part from Buildtak was a nightmare (I've ruined a sheet of Buildtak trying to remove a failed PETG print). However, with PC the process was really really easy, like magic! It sticks without issues to the surface (I'm having a bit of elephant foot, I still need to adjust the Z offset) and you cannot remove it by hand after the print (really well sticked to the surface) but as Whitewolf suggested, I just removed the surface from the bed, bend it a bit, and... voila! It came off in a second, undamaged! (both, surface and part). I was crying after it xD.
The only problem I'm facing is that, as the surface I bought wasn't manufactured for 3dprinting, the surface is not totally flat (in fact, as per the sensor, is not flat at all), and the bulldog clips are not helping either, although the piezo sensor seems to be doing a really good job detecting the unevenness of the surface and the duet is compensating it. I think the white sheet I bought is more straight, so I will sand it too and give it a try. Not sure if I can use the heated bed to try to make it more straight, my suspect is that I will need more than 100 degrees and that I will do more harm than good.
So far (I just printed a couple of parts, just in PETG, with no heated bed and no warp at all), I'm really happy, this seems to be really promising, and in contrast with the Buildtak, I'm not afraid of ruining it, as A) I can just sand it again, or B) I can flip it over, sand the bottom, and use it again, or C) Is cheaper than Buildtak, so I just can buy another one :D.
Cheers!
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you need to sand the other side and clip it from the other side… sorry i forgot to mention that before.... most PC has a cup... being sure to not have the cup upward is the key to a closly flat surface.
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LOL, I see… I've sanded that side because it was in a bit worse condition, with some scratches, and I thought that "if I ruin it, is not the best side" xD. Funny thing, I did over a small table, without adding anything between the shit and the table, so now the "best" side is full of scratches
(not important at all, after the sand all will be gone...)I will sand the other side then and test again, thanks!
Regards
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sheet* and the table
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If I bought Lexan sheets offered up for use as window panes and whatnot, are you guys saying these typically have a scooped side? Or are you talking about PC from other sources?
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Not sure about window pane grade…. I have seen many varations of PC some costing a lot more. I am sure those versions have better tolerences and are probably machined flat... I am referring to the cheap stuff on amazon and other sources.
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Some of the versions specifically designed for glazing may have UV coatings etc
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Some of the versions specifically designed for glazing may have UV coatings etc
I've got some 100 and 150 grit sand pads for my random orbital sander. I'll experiment with using them to scuff up the surface of the Lexan, clamp it directly onto my build plate (no thermal pads or anything in between) and give this a try. I wonder if any coatings that might be there will be removed by this? Or, barring that, whether they'll make any difference?
I print a lot of PLA, PETG, and more recently I've been experimenting with ASA. I've got a PC/ASA blend I want to try as well, and I've experimented with PCMax and eSun's ePC before as well, and some things like Taulman's alloy 910. I probably won't go back to PCMax until I've got some kind of enclosure. The ePC was too brittle to be of much use to me. The others I'd really like to see if they'll stick to this Lexan.
I've never actuall printed anything without a heated bed. Not sure if that really interests me, to be honest. I not only like how the heat helps things stick, but the difference between heat and no heat helps me remove things since the hold on the build plate reduces as the prints cool down to room temperature and there's that little bit of shrinkage of the filament, breaking the bonds that hold it. Been printing on PEI for many moons now, and I love it. I'm really just curious how this Lexan compares to PEI.
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The problem with heat is depending on the filament you can make things stick so good that you wont be able to get them off.
Things like nylon 910 will benefit from 55c and others like acetal pom…. This really isnt a new idea go read about Fleks3D build plate. heat is not a friend of PC in most situations.
Especially heat above 55c i even got Igus Iglidur filament to weld to the build plate at 60c (i have tested stuff up to 120c and had a couple situations where it was extremely difficult to even sand the old filament off the bed plate.
Also the PC plate begins to warp above 55c
My rule of thumb really is no heat until i come across a filament that shows signs of warping then i use a brim or add 55c heat
The trickiest filaments have been acetal pom and the taulman nylon series but they are doable with 55c
Also when you say lexan are you talking clear lexan? if you look at my posts a few up where i show the photo of the Fleks3d build plate... i can tell you from experience that clear does not stick as well as the black on such a large range of filaments... Fleks3d is a commercial build plate from clear lexan and inwas never getting the results that i am from black PC
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read posts like these: https://www.duet3d.com/forum/thread.php?pid=18708#p18708
also read about Fleks3d build plate for part removal the key is not heat, it really isnt needed
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Hi there!
After several prints I must say I'm still impressed with PC, it's the best print surface I've used so far, although is not perfect of course… here a few impressions and a question:
- PLA and PETG (so far, the materials I've printed with) sticks perfectly... sometimes it sticks too much.
- The Z Offset is really important and depends on the material you're printing with... for PLA I need to setup a 0.1 offset, for PETG I'm still testing, but 0'25 seems to be OK. If you're closed to the bed, you won't be able to unstick the part without breaking it...
- I have a white and a transparent PC sheet, the white one seems to be more flat than the transparent one, and sticks more too... I will need to sand it a bit more probably.
- Usually bending the sheet is enough to unstick the part... it starts to "crack" a bit, and then you can remove it. The problem here is that if the part is too small or too thin, the part will bend with the bed, and it's harder to remove.
And now the question for @Whitewolf:
After you told me about the "cup", I've been using the bulldog clips and the surface is really flat as per the probe, however, I've observed that even though the parts are not warped from the bed, the base of the part seems to be bended... and I'm thinking the problem is that even with the clips, the plastic bend the surface with cooling down, so the part is a bit bended, similarly when you've warp problems... did you observed this? Any advice?Cheers!
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Instead of sanding, would matte (or frosted or satin) finish PC work ?
For example:
https://www.amazon.com/gp/product/B00II1QY9Y/ref=s9_dcacsd_dcoop_bw_c_x_1_w -
Hi there!
After several prints I must say I'm still impressed with PC, it's the best print surface I've used so far, although is not perfect of course… here a few impressions and a question:
- PLA and PETG (so far, the materials I've printed with) sticks perfectly... sometimes it sticks too much.
- The Z Offset is really important and depends on the material you're printing with... for PLA I need to setup a 0.1 offset, for PETG I'm still testing, but 0'25 seems to be OK. If you're closed to the bed, you won't be able to unstick the part without breaking it...
- I have a white and a transparent PC sheet, the white one seems to be more flat than the transparent one, and sticks more too... I will need to sand it a bit more probably.
- Usually bending the sheet is enough to unstick the part... it starts to "crack" a bit, and then you can remove it. The problem here is that if the part is too small or too thin, the part will bend with the bed, and it's harder to remove.
And now the question for @Whitewolf:
After you told me about the "cup", I've been using the bulldog clips and the surface is really flat as per the probe, however, I've observed that even though the parts are not warped from the bed, the base of the part seems to be bended... and I'm thinking the problem is that even with the clips, the plastic bend the surface with cooling down, so the part is a bit bended, similarly when you've warp problems... did you observed this? Any advice?Cheers!
I do not use PC, but PEI as a build surface, which has the "cup" and is secured with a clamp to keep it flat, and have experienced the same thing – the bottom of very large prints will "cup" in the same way that the build surface would if released from the clamps.
I wonder if there is a way to get pieces of plastic that "cup" to be more flat by relieving the internal stresses that causes the warping? Maybe heating the pieces in an oven at controlled temperatures, while held between two precision flat plates?
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This is why these surfaces are generally bonded with 3M 468 adhesive to the aluminium/glass substrate. Otherwise they warp too.
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This is why these surfaces are generally bonded with 3M 468 adhesive to the aluminium/glass substrate. Otherwise they warp too.
Only problem with that is you would need a mic6 plate underneath to be effective.
Also it would remove one of the key elements that make working with PC build plates easy and that is the ability to remove plates and flex to pop the part off and you would end up with some situations where parts were very difficult to remove
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The phenomenon we are taking about isn't due to the build surface warping – it seems to be due to internal stresses of the build plate, when held flat, being transferred to the print. The prints are flat on the build plate, and the build plate is flat, but upon removal, the bottom of the print becomes convex, to a similar degree to the curve of the buildplate, if the buildplate wasn't being held flat -- I don't think adhesive under the plastic is going to alleviate this situation.
Also, keep in mind, I'm talking about thick pieces of PC or PEI, 3mm minimum in thickness.
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Hi there!
After several prints I must say I'm still impressed with PC, it's the best print surface I've used so far, although is not perfect of course… here a few impressions and a question:
- PLA and PETG (so far, the materials I've printed with) sticks perfectly... sometimes it sticks too much.
- The Z Offset is really important and depends on the material you're printing with... for PLA I need to setup a 0.1 offset, for PETG I'm still testing, but 0'25 seems to be OK. If you're closed to the bed, you won't be able to unstick the part without breaking it...
- I have a white and a transparent PC sheet, the white one seems to be more flat than the transparent one, and sticks more too... I will need to sand it a bit more probably.
- Usually bending the sheet is enough to unstick the part... it starts to "crack" a bit, and then you can remove it. The problem here is that if the part is too small or too thin, the part will bend with the bed, and it's harder to remove.
And now the question for @Whitewolf:
After you told me about the "cup", I've been using the bulldog clips and the surface is really flat as per the probe, however, I've observed that even though the parts are not warped from the bed, the base of the part seems to be bended... and I'm thinking the problem is that even with the clips, the plastic bend the surface with cooling down, so the part is a bit bended, similarly when you've warp problems... did you observed this? Any advice?Cheers!
Are you using heat with your bed? The majority of parts should easily pop off if no bed heat is used and it is properly sanded… I see many people doing things differently, different grit sand papers etc adding bed heat etc and then wondering why their results vary. I didnt start with 60 grit... i chose it because it worked better than others
You are sanding differently, you are squishing, are you running bed heat too? Honestly this works flawlessly for me, time and time again... it is not until you introduce these other elements that things tend not to work.
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@bot:
Hi there!
After several prints I must say I'm still impressed with PC, it's the best print surface I've used so far, although is not perfect of course… here a few impressions and a question:
- PLA and PETG (so far, the materials I've printed with) sticks perfectly... sometimes it sticks too much.
- The Z Offset is really important and depends on the material you're printing with... for PLA I need to setup a 0.1 offset, for PETG I'm still testing, but 0'25 seems to be OK. If you're closed to the bed, you won't be able to unstick the part without breaking it...
- I have a white and a transparent PC sheet, the white one seems to be more flat than the transparent one, and sticks more too... I will need to sand it a bit more probably.
- Usually bending the sheet is enough to unstick the part... it starts to "crack" a bit, and then you can remove it. The problem here is that if the part is too small or too thin, the part will bend with the bed, and it's harder to remove.
And now the question for @Whitewolf:
After you told me about the "cup", I've been using the bulldog clips and the surface is really flat as per the probe, however, I've observed that even though the parts are not warped from the bed, the base of the part seems to be bended... and I'm thinking the problem is that even with the clips, the plastic bend the surface with cooling down, so the part is a bit bended, similarly when you've warp problems... did you observed this? Any advice?Cheers!
I do not use PC, but PEI as a build surface, which has the "cup" and is secured with a clamp to keep it flat, and have experienced the same thing – the bottom of very large prints will "cup" in the same way that the build surface would if released from the clamps.
I wonder if there is a way to get pieces of plastic that "cup" to be more flat by relieving the internal stresses that causes the warping? Maybe heating the pieces in an oven at controlled temperatures, while held between two precision flat plates?
Honestly i think bed heat is the issue here, most people run PEI with a heated bed.
I have printed objects as large as 80mil vase bottoms without any cupping…. but then again i do not use a heated bed and I am not having to squish anything to get first layer adhesion.... with the exception of a couple specialty filaments like Igus Iglidur, Nylon and Acetal POM. with those i either run a large brim with no bed heat or 55c bed heat with no brim but only on those specialty filaments, i have not had issues with 0 bed heat with any of the others that i have tested
I also always print at the low end of temps... if these guys are running PLA for instance at 215 then they are going to get a whole different set of issues.
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Heat was definitely my theory, as well. If Okercho responds positively that he was using bed heat, then I will consider that the primary suspected culprit.
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This is why these surfaces are generally bonded with 3M 468 adhesive to the aluminium/glass substrate. Otherwise they warp too.
Only problem with that is you would need a mic6 plate underneath to be effective.
Also it would remove one of the key elements that make working with PC build plates easy and that is the ability to remove plates and flex to pop the part off and you would end up with some situations where parts were very difficult to remove
My current printbite surface is bonded to a machined tooling plate. Or I'd use glass.
I've had a sample of 3mm thick PEI which deformed as the bed heated up.
I haven't seen the effect you are describing in prints myself so a I apologise if I assumed this was the PC deforming under heating.
