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Polycarbonate print platform

Posted: Sun Nov 11, 2012 1:40 am
by pleppik
I've been experimenting with a variety of platform materials recently. I plan to write up what I've learned soon, but in the meanwhile...One material I've had really good results with is polycarbonate sheet (aka Lexan). The adhesion is good, it doesn't warp, and removal is relatively easy.

Has anyone else tried this?

Re: Polycarbonate print platform

Posted: Sun Nov 11, 2012 2:41 am
by doraemon
I think at work we tried a platform of acrylic (or maybe polycarb) that worked poorly, but it may have been the ESD coating on it that caused the adhesion problems. I was going to try styrene, but haven't had time to figure out a good way to hold it flat to a support layer. My initial trial using CA to bond it to glass worked a bit too well; I no longer can remove it from the glass w/o risking shattering it. :(

Re: Polycarbonate print platform

Posted: Sun Nov 11, 2012 3:28 am
by roller
Pleppik, was that on a Mini (low temp) or regular Up (higher temp)?

Re: Polycarbonate print platform

Posted: Sun Nov 11, 2012 4:11 am
by pleppik
This was on an Up Plus, so the platform is at 100C, not the 50C of a mini. If you try it on a Mini, I'd be interested to know the results.

I have also been experimenting with acrylic (Plexiglass). Acrylic adheres well, but 100C is above the temperature where acrylic starts to deform, so acrylic platforms were single use at 100C (they warp too much to be usable a second time). Polycarbonate has a heat deflection temperature well above 100C, so warping has not been a problem. Acrylic might be a suitable platform on a Mini.

Re: Polycarbonate print platform

Posted: Sun Nov 11, 2012 10:46 am
by eyUP
I've successfully printed on cold Acrylic in the past. After a few models however, it's not always possible to remove the model/raft cleanly so you end up having to replace the sheet.

Re: Polycarbonate print platform

Posted: Sun Nov 11, 2012 11:10 am
by mr6k
I also tried an experiment using hot setting laminating sheets, the type used to sandwich paper sheets to protect them. I just held one sheet to the platform (UP Plus) with kapton tape around the edge, the upper part of the sheet was the internal laminate that goes clear when laminated. ABS stuck to it pretty well and what's more you can see the temperature gradient across the platform on the sheet as the heat makes the laminate go clear. Of course it does not go cloudy again, once used. Model separates quite well but I think it may have pulled the thin laminate surface with it. I only tried it once as the laminate sheet is thin and not robust enough to hold very flat.

cheers

Peter

Re: Polycarbonate print platform

Posted: Sun Nov 11, 2012 3:07 pm
by roller
I'll try it our on the mini when I get a change - I have a fair bit of polycarb lying around the I use on the CNC.

Re: Polycarbonate print platform

Posted: Tue Nov 20, 2012 6:54 pm
by Fred
What thickness of polycarbonate did you find worked well? I'm about to order some on eBay and wasn't sure whether to go thicker to reduce warping of the sheet or thinner to let the heat through.

Re: Polycarbonate print platform

Posted: Tue Nov 20, 2012 8:32 pm
by ahd71
I was inspired and did a quick test with 5mm polycarbonate (also known as PC, makrolon etc) on the Up! Mini.

The adhesion was excellent for that small part, in fact so good that I had problems removing the part, even after the PC was cooled down. It would probably have been easier if it was a larger print so I could have used the force of bending the polycarbonat slightly.

Printing was done "raftles" (my first attempt ever) and only with a small testcylinder (diameter 10mm and height 10mm) in ABS.

I calibrated the print height to ~0.2mm below nozzle, but forgot to lower the platform while preheating the nozzle before print so I got a tiny hole in the PC due to melting. I fixed the PC with some temporary "oversized clamps" (the ones that came with the mini was not big enough for existing platform + 5mm) which limited the practicle build area. I have to find some other method of fixing it onto the heated platform. The PC was completely new and unexposed to fingerprints etc, so it will be interesting to see variations after that it has been used more.

Conclusion: Will definitly try more with some larger prints eventually.

Re: Polycarbonate print platform

Posted: Tue Nov 20, 2012 9:42 pm
by roller
It's worth being careful with heating polycarb as it's one of the plastics that will readily give off a lot of nasties if heated sufficiently - I think including hydrogen cyanide which is why it doesn't get laser cut. Should be ok on your Mini hotbed which is relatively cool but when you accidentally crash your head into it I'd clear all the air in that room.

Re: Polycarbonate print platform

Posted: Tue Nov 20, 2012 9:45 pm
by ahd71
Good point!
(And in my case it was just a little point where the nozzle was close so it didn't kill me fortunatly)

Re: Polycarbonate print platform

Posted: Wed Nov 21, 2012 11:45 pm
by pleppik
Fred wrote:What thickness of polycarbonate did you find worked well? I'm about to order some on eBay and wasn't sure whether to go thicker to reduce warping of the sheet or thinner to let the heat through.
I used the 2mm polycarbonate sheet which is commonly available at home improvement stores. It seems to be a good thickness, as it is flexible enough to bend to get the print off, but does not flex under normal printing.

Warping has not been a problem at all, and I've used the same sheet for dozens of models. It's just as flat as when I started, just dirtier and scratched.

I would not be concerned about burning the polycarbonate under these conditions--your nozzle should not get hot enough to melt the polycarbonate, much less burn or scorch it. On the occasions when my nozzle has crashed into the polycarbonate, it has scratched (not melted) the plate.

Re: Polycarbonate print platform

Posted: Fri Nov 30, 2012 4:46 pm
by Fred
I just tried printing on polycarbonate and seemed to get a good result from the wall thickness test model (flat and about 7cm square) with no lift. A little flexing of the polycarbonate and it popped right off. A little trickier to remove the bit where the printer "wipes its nose" before printing. I also got a little melt when testing the nozzle height as the printer seems to sit in one place and pump out filament. Not sure it's supposed to do that.

I'm also going to try kapton on glass. One tip is not to confuse these two substrates! Cleaning your polycarbonate with acetone melts it slightly and gives it a scuffed finish.

Re: Polycarbonate print platform

Posted: Sat Dec 01, 2012 2:04 am
by pleppik
Fred wrote:I just tried printing on polycarbonate and seemed to get a good result from the wall thickness test model (flat and about 7cm square) with no lift. A little flexing of the polycarbonate and it popped right off. A little trickier to remove the bit where the printer "wipes its nose" before printing. I also got a little melt when testing the nozzle height as the printer seems to sit in one place and pump out filament. Not sure it's supposed to do that.

I'm also going to try kapton on glass. One tip is not to confuse these two substrates! Cleaning your polycarbonate with acetone melts it slightly and gives it a scuffed finish.
I've found that a single-edge razor blade scraper works really well to pop off any stubborn corners and scrape off any sticky bits of raft material. It will scratch the sheet, but the scratches don't seem to cause a problem (I've probably done 75-100 prints on a single sheet; it's getting really beat up but still works great).

For cleaning, I've just been wiping with a damp paper towel then drying.

Re: Polycarbonate print platform

Posted: Sat Dec 01, 2012 12:26 pm
by pp3dp.nl
I have had success with PC for a while now, too. We had a batch made on a CNC for us and we sell/give them with Ups. We designed one especially for the Mini so that the nozzle doesn't touch the metal bracket (so the sides of the PC plate that slide in are thinner). But they also fit the Plus and I always use them now. Models come off relatively easy and you can flex it, too. Grooves in the PC make adhesion better.

Re: Polycarbonate print platform

Posted: Sat Dec 01, 2012 12:55 pm
by ahd71
Hi pp3dp.nl,

Do you have a picture or drawing of the board you made for the mini that you could post here? If you dont consider it intellectual property for your business of course!

Br ahd71

Re: Polycarbonate print platform

Posted: Sat Dec 01, 2012 2:19 pm
by pp3dp.nl
Hello,

I made some pictures, check them below.
PC1.jpg

PC2Mini.jpg
PC3Plus.jpg
We made these sheets to sell them for the Up but of course anyone can make these if they want to. Polycarbonate is tough so I think it will last long, occassionally I wil take the pliers and remove all the small bits in between and sand it down a little with some sandpaper. I have tried cleaning it with acetone but the next models sticked too well and the remnants were hard to remove.

Re: Polycarbonate print platform

Posted: Sat Dec 01, 2012 2:53 pm
by ahd71
Excellent! Thank you very much for taking the pictures and telling me/us more. I will definitly try more with PC.

BR/ahd71

Re: Polycarbonate print platform

Posted: Fri Dec 07, 2012 1:14 am
by pleppik
Just an update....after probably 100-200 prints, my polycarbonate platform got sufficiently scratched that the plastic would no longer adhere.

So this is definitely a consumable item. On the other hand, I got a 12x24 sheet of Lexan from Home Depot for $14, enough to make 8 platforms. That's probably a year's supply.

Re: Polycarbonate print platform

Posted: Fri Dec 07, 2012 6:47 am
by scubamatt41
Please allow me to share my printing findings on PMMA at my "PMMA print board" topic post

http://pp3dp.com/forum/viewtopic.php?f= ... 84&start=0

Thanks roller!