Polycarbonate build plate…. No bed heat Success!!!
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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.
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@bot:
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.
He has done many things differently in preperation of his plate and the way he prints. I did a lot of testing before posting this thread… from starting with 120 grit paper on down till i settled on 60 grit and wet sanding.
I tried all kinds of bed temps from 0 all the way up to 120c, i tried all kinds of filaments and different z offsets for every filament.... i even moved hotend temps up and down to see the results.
I can tell you from experience, i had parts that were impossible to remove and needed sanding just to get the filament off. I had parts that removed too easily etc... every variable gave different results.
If he has done things right there should not be more than a little twist of the part or a little tap with a scraper to get the part off (yes i have even removed 200mm single wall vases without breaking the part just by flexing the plate but flexing is usually not required for most parts only about 10% of the time if done right)
If people want to venture off and do things differently then they will experience the same issues i experienced before finding what works and what doesnt.
The point of me sharing the advice and thread was so others could skip past all that and get on with printing.
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Here is my x carriage printed on this very plate with Taulman Guidl!ne (PETG)
One photo i gave a slight angle so you can see the surface, the other is direct on so you can see it is completely flat
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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.
That is the problem, it does deform if bed heat is used, you also get difficult to remove parts if heat is used… the only temp that I have found that can be used is up to 55c but this should only be done if required with a select few filaments.
My rule of thumb is no heat unless i experience warping then ill try a brim if that doesnt work then ill set bed temp up to 55c but i have only had to do this with a select few specialty engineering filaments... so if someone finds themselves having different results then they need to ask themselves what they are doing differently, did they follow my advice to a T or did they venture off the path and do things a little differently
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I'm not trying to do things differently. If I did something in a different way is because I didn't understand it correctly, or because my DIY skills and tools are not the best for the job…
I'm not using heat bed since I'm using PC as build plate, also I'm only having "cupping problems" in the bottom of the parts with PETG, a material I didn't use a lot before (because I had warping problems) and which I'm still struggling with... With PLA I'm not having problems at all, nor for removing, nor for sticking, although is true that I din't find the right point yet, where there is not "elephant foot", I know I'm still squishing PLA a bit.
For PETG I tried different Z offsets, and I had a mix of results, sometimes I wasn't able to remove the part (and I broke it trying to remove it) because I was too close (0'20 offset) to the bed, and sometimes having problems with the circles in the first layer because I was too far (0'25 offset), apart from the fact that I'm having problems with the temperature and flow for this material, but that's another story.
Additionally I have 2 PC sheets, one transparent (at least, it was transparent at the beginning) and another one white. The transparent one is "cupped" (not sure about the word, but you all know what I mean), and with the bulldog clips well positioned, the bed seems really flat, you can press and the sheet won't move down in any point, and the probe says the surface is quite well leveled, however, when I remove the clips, the cup is more visible than at the beginning, and I can see the bottom of the part is "cupped" too when I remove it successfully. The white one is perfectly flat, but as I had a problem when I tried to remove one piece, I couldn't use it until today, when I sanded it again. PETG anyway is a material that makes a lot of force when cooling down, I used blue painter tape and it ripped out the tape from the bed when cooling...
@Whitewolf, I'm sorry if you felt like I'm criticizing you, I'm not, I truly appreciate what you did sharing this with us, and trust me, this is the best surface I've ever used (even if apparently I didn't follow the instructions :P), but you've been using it for a long time meanwhile I'm still learning how to use it, and I just ask to take advantage of your experience, to try not to fail in the same ways you failed in the past, anda I'm just trying to share my experience from a newbie point of view, sharing my failures, my successes, what I did and how, so I can receive advice and others can learn from me, same I'm trying to learn from you and others in this forum.
Regards
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The convex surface I describe is only on LARGE surface area prints – like 200 mm diameter flat circles, or large rectangular areas. Small prints like the ones which you (Whitewolf) show do not exhibit any convex bottom surface. Also, it does sound very similar to what Okercho is describing: the print is flat when adhered to the surface, the surface is flat when clamped (or bonded) to the tooling plate, but when the print is removed, the bottom surface sometimes reveals a convex condition.
At first, I too suspected heat -- perhaps the differential of surface temperature from the middle of the bed to the outer edge causes a differential contraction rate when printing/cooling. However, on printers with different surfaces, but which exhibit less even heating on the heat bed, I do not observe this phenomenon -- only on the printers which I run which have a convex/concave (depending on which way you look at the piece) print surface that has been clamped down do I observe this.
