PEI bed surface

Folks - I had been following a looong thread on SeeMeCNC about using a sheet of PEI as a bed surface on 3D printers. Everyone kept saying it was a miracle material - people were easily able to print both PLA and ABS, with a heated bed of course, with perfect adesion but easy extraction once the bed cools off enough. No glue, no ABS juice, no treatment whatsoever other than keeping it clean.

Well, I finally tried it out last weekend… Got a 0.040" thick sheet from McMaster-Carr, along with a 12"x12" sheet of 3M 468MP transfer adhesive. Removed the PET from the TAZ’s bed and went to town gluing the PEI down. It definitely takes a bit of careful work to adhere it nice and flat.

I readjusted my bed level and height and… Voila! I’m printing some fairly big parts (the TAZ 4 Z motor mounts, top plates, etc) with perfect adhesion, no warpage. These are long flat parts with sharp corners and I’m using quite a bit of infill to make them stiff. It is a night and day difference to what I went through trying to get ABS to stick to the PET tape, even with ABS juice. I haven’t printed with PLA yet, but from what I’ve read, that will be no trouble at all!

It’s also fairly thick and strong, so it will take quite a lot of effort to mess it up. So far, I’m super happy with this upgrade and whole heartedly recommend it to anyone having trouble with getting their parts to stick!

This has been on my list of upgrades to try for a while now. I’ve just never got around to actually ordering it. About how much did the adhesive and the PEI run you if you don’t mind me asking, and how does the adhesive seem to be holding up to the heat?

Don’t mind at all - I bought the adhesive from Digikey for $5.50 or so, IIRC… That’s for a 12x12" sheet. Most folks have been buying a thinner roll from Amazon as it’s easier to manage - I believe a a 15 yard roll of 1 or 2" adhesive is 6 or 7 bucks from Amazon as well. I actually bought both the sheet and the roll just in case I messed up the 12" square sheet :slight_smile: There were quite a few bubbles, but I used an x-acto knife and made little cuts on each bubble. The plastic is thick enough that any remaining irregularities are unlikely to transfer to the surface, though!

I bought the PEI from McMaster… Again i ordered too much just in case, and bought a 12x24" sheet - I think it was around $35? I think the 12x12" sheet is around $20.

The adhesive is holding up great so far. I’ve printed maybe half a roll of ABS and a bit of PLA, so I don’t want to promise that this will last forever, but some of the guys on the SeeMeCNC forum (particularly Michael Hackney) have printed on the same sheet for weeks of intensive printing, using the same adhesive, so I’m hopeful it’ll hold up :slight_smile:

The bit of PLA I printed was just an hour ago - a fairly large, flat part 4" x 7" roughly. I heated up the bed to 60deg and let her rip, worked great. No lifting, everything stuck perfectly and came off easily once the bed cooled down enough :slight_smile:

Huh, alright, I’ll give this a shot!

Edit, parts on the way. Ended up getting the adhesive from Amazon. SHould all be here in a few days.

This stuff is Magical. Go buy some and do this mod today. Go ahead, I’ll wait.

I got my parts in this weekend and proeeded to install it on the existing glass plate using the adhesive outlined above. It went on in about 10 minutes. I had to trim the plastic square to match the plate a bit, but I was able to do that with a pair of sheet metal shears easily enough. I’ve printed 4 things on it so far, and it all sticks like glue until the bed cools down, then it pops off like nothing. I’ve tried almost all of the alternative bed materials people have proposed so far, and this is by far the best one I’ve tried yet.

Next up I think i’ll get a 3mm aluminum plate and attach a new lulzbot 24v heater to the bottom of the plate to try and save some mass on the Y axis. Definitly no downside so far to this modification, at least for printing with ABS.

Sweet!

Thank you for the updates!

Awesome :slight_smile: glad it’s working well for you! Let us know how things go with the aluminum plate… In my experience, it might be hard to find a plate of aluminum that thin that is and stays as flat as a piece of glass… But it would be a great way to save weight!

I’ve got a piece of 4mm aircraft grade milled aluminum plate on my AO-10x at the moment and it seems to do ok at the smaller size. It’s on a rigid plate bed though. the larger 24v taz nonrigid silicone bed might require something thicker. Will have to try it and see

The .040 PEI is pretty thick. How well does it conduct heat? Do you have to raise the bed temperature any?

Amazon has 12x12 in sheets of 3M 486MP adhesive in 6 packs for a pretty reasonable price.

http://www.amazon.com/gp/product/B007Y7D5NQ

Kenny

I didn’t notice any need to increase the temperature at all. I actually think I could probably lower it quite a bit and it would still stick just fine. This stuff is just that sticky!

I actually bought my sheets from that amazon listing, but they only had one more in stock so I put the digikey listing in there instead.

Is the temp range on the transfer tape sufficient for the bed?

Seems to be holding up quite well so far and doesn’t come loose under heat conditions either. I won’t be able to say 100% personally until i’ve ran it for a few weeks, but it’s within the temperature tolrenace range for the tape so it should.

http://www.digikey.com/product-detail/en/12X12-6-468MP/3M9720-ND/2649265

Says on this spec page that the upper temp is 100F or 38C.

Seems DigiKey is incorrect.

According to the 3M spec sheet:

Temperature/Heat Resistance> : 3M High Performance Acrylic Adhesive 200MP is usable for short periods (minutes, hours) at temperatures up to 400F (204C) and for intermittent longer periods (days, weeks) up to 300F (149C).

Kenny

Well, whatever the actual rating is, it’s holding up pretty well so far.

If that’s the case I’m trying it.

Can it be removed for replacement of the PEI surface? I would hate to apply anything permanent to that expensive bed assembly.

The stuff is pretty sticky. I think it would come off without too many problems, but the PEI probably would not survive the removal process. The glass shouldn’t be adversly affected. You could also probably put a second PEI sheet over a damaged one without issue if necessary.

Alternativly, you could probably hold the PEI sheet down with some sort of edge clamp and not adhere it with adhesive. The PEI itself is slightly brittle and will crack if it flexes too much. Impact doesn’t seem to affect it much at all. I’m guessing it has pretty good compressive strength but not alot of flex. Potentially a thicker sheet could be used as a standalone non adhered unit. It doesn’t seem to be much of an insulator so increasing the thickness of the sheet double or even triple probably would not adversly affect the heated bed operation. You could also use a less sticky grade of adhesive, though you might end up having to replace it due to thermal concerns. That or maybe smaller adhesive strips near the center and edge to not adhere the entire thing down but still keep it from shifting?

Good info. Thanks.

Another place to purchase the PEI sheet…slightly less expensive than the McMaster one. $28.29 with free shipping for a 12"x24" sheet 0.040" thick. I’m putting mine on today :smiley:

http://www.zoro.com/g/Natural%20Grade%20PEI%20Sheet%20Stock%2012"%20x%2024"/00101341/None