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mhackney wrote:I posted my experience on the google delta group and a fellow replied that he has had good experience with http://www.itapestore.com/3mthermalpad5 ... 1foot.aspx

The problem is that I could not find it in 12" squares. You would need 2 pieces of this for our beds.

A pack of 6 of the transfer tape is available on Amazon : http://www.amazon.com/TapeCase-468MP-12 ... 22+x+12%22

That's a different tape but might work given it's temp rating. The other stuff has a high thermal conductivity too. Good deal for 6 though!

mhackney wrote:That's a different tape but might work given it's temp rating. The other stuff has a high thermal conductivity too. Good deal for 6 though!

Do you think that the tape would work better than your silicone solution?

It might be easier to apply and would be ready to use. My only concern is if the adhesive will hold at 100°C or so. At least with silicone, it cures and will not soften at temperature. These materials may well work but I don't have experience with them.

my results with ABS on the .030" PEI + 3M tape are mixed...
good adhesion of print, but a few edge curls of plate full of Kossel mini parts.
BUT, I suspect culprit could be print surface not really being 100C. I could hold my finger on table for 10 sec or so... if it WAS 100 I don't think I could do that. right?
I did not have my IR temp gauge handy to verify.

Could the .030" PEI and the thick 3M adhesive be thermally insulating print??
Also my tape has a few air bubbles, probably not helping either.

I am eager to hear how the .009" stuff works.


I have not had time to try the .003 stuff (from Hyde with adhesive)

Yes, I think 10 seconds would be uncomfortably hot for a finger at 100°C!

PEI is not very thermally conductive and the adhesive probably isn't either. You may need to wait a little longer and measure the temp. Also make sure to clean the PEI with alcohol.

mhackney wrote:It might be easier to apply and would be ready to use. My only concern is if the adhesive will hold at 100°C or so. At least with silicone, it cures and will not soften at temperature. These materials may well work but I don't have experience with them.

3M's data sheet for the 468MP adhesive says maximum operating temperature is 450F. I'm pretty sure that was the same stuff that CS Hyde was laminating the thin PEI films to. I tried pulling a piece off the bed immediately after a print finished while the bed was still hot. There was maybe a small bit of localized lift, but it snapped right back.

bdjohns1 wrote:

mhackney wrote:It might be easier to apply and would be ready to use. My only concern is if the adhesive will hold at 100°C or so. At least with silicone, it cures and will not soften at temperature. These materials may well work but I don't have experience with them.

3M's data sheet for the 468MP adhesive says maximum operating temperature is 450F. I'm pretty sure that was the same stuff that CS Hyde was laminating the thin PEI films to. I tried pulling a piece off the bed immediately after a print finished while the bed was still hot. There was maybe a small bit of localized lift, but it snapped right back.

How hard is it to use the tape and not get the bubbles under the PEI?

I had a few bubbles when I applied the 0.9mm sheet, but I figure that they'd be relatively insignificant versus the thickness of the sheet. I just laid down strips around the perimeter of my glass and across the middle, giving me maybe 40% "infill" with the adhesive. I'll see how it prints over the weekend.

bdjohns1 wrote:I had a few bubbles when I applied the 0.9mm sheet, but I figure that they'd be relatively insignificant versus the thickness of the sheet. I just laid down strips around the perimeter of my glass and across the middle, giving me maybe 40% "infill" with the adhesive. I'll see how it prints over the weekend.

Please let us know what you find out.

Eaglezsoar wrote:

bdjohns1 wrote:I had a few bubbles when I applied the 0.9mm sheet, but I figure that they'd be relatively insignificant versus the thickness of the sheet. I just laid down strips around the perimeter of my glass and across the middle, giving me maybe 40% "infill" with the adhesive. I'll see how it prints over the weekend.

Please let us know what you find out.

So far so good. The sheet I got from AmazonSupply was glossy on both sides. If I try and use the top surface as a mirror, there are a few minor distortions that suggest it's not perfectly flat, but as best I can tell, the distortion isn't practically significant to parts. I'll have to dig out my feeler gauges and see if I can even get a 0.0015" feeler under a straightedge. Much better than the thin film.

The sheet is ~2.3mm thick. The 468MP transfer tape I used is 0.1mm (100 micron) thick, according to 3M. The bubbles I had were fairly small - the bigger problem with the transfer tape (at least in narrow strips) is that it wants to stretch / fold weirdly coming off the roll, so it was hard to get it down perfectly flat, but it compressed well, so I don't think the imperfections I'd have are even that big.

That's good news. It sounds as though you should be fine to print on it.
Thanks for the tip on the tape, I just ordered a roll of the 1" and hope to have it on Tuesday.
I tried the silicone method but I just made a mess and the PEI did not stick the way I had hoped.
I had a bear of a time getting the silicone off the glass, even razor blade leaves a film behind.

Yeah, I just did the Pixar Luxo Jr. lamp today, no problems printing or getting parts up (made it in white PLA).

I took a straightedge to it, and there's no gap between the tape strips that can let light through. I've got an overall concavity about 0.2mm I need to deal with, but no biggie.

Interesting stuff! Has anyone tried thicker sheets (1/8") and just clipping it to the pcb and not using the glass at all? I have no idea how hard this stuff is as I haven't seen it in person.

xnaron wrote:Interesting stuff! Has anyone tried thicker sheets (1/8") and just clipping it to the pcb and not using the glass at all? I have no idea how hard this stuff is as I haven't seen it in person.

I don't think anyone has tried that because of the cost factor. $40 for a square foot for that thickness which if it works I guess is not that expensive.
That would be an interesting experiment.

Hey all, I decided to try out a sheet of adhesive backed .003" PEI from CS Hyde, http://tinyurl.com/q8wgpb6. It's a 12" x 12" sheet, so I just traced around the borosilicate with a marker and cut it to be slightly smaller than the glass. Sticking it down took 15 minutes or so, peeling it back only an inch at a time and slowly smoothing it down to prevent bubbles. I've only run one test on it so far, but it seems to work just as advertised.

It also left an interesting shiny ripple pattern on the bottom of the print, which some people may not be fond of...it's hard to capture with a picture, so here's a short vid: http://www.youtube.com/watch?v=eiW7gWah ... e=youtu.be

How is this stuff holding up after numerous prints? Still holds just as good as day one? Does it damage fairly easily?

I'm using the thicker .03" material held down with silicone. I've printed hundreds of parts and the PEI looks exactly like it did when I attached it. I am still very pleased with PEI.

So after printing a few more things, I've found that the adhesive backed PEI I'm using doesn't let go the way it's supposed to. I'm printing ABS with the bed at 95C, and even after letting the print sit all night, I still had to pry it off. Might try switching to thicker stuff.

Glacian22 wrote:So after printing a few more things, I've found that the adhesive backed PEI I'm using doesn't let go the way it's supposed to. I'm printing ABS with the bed at 95C, and even after letting the print sit all night, I still had to pry it off. Might try switching to thicker stuff.

Try turning the bed heat down to 85c, it might make a difference.

mhackney wrote:I'm using the thicker .03" material held down with silicone. I've printed hundreds of parts and the PEI looks exactly like it did when I attached it. I am still very pleased with PEI.

Thanks. I am picking up some to try.

ok guys thiss is awesome news..

leads to me to two different thoughts.

1. adhering the PEI to a metal backing seems like a good idea.

OR

2. getting a very thick piece of PEI (in lieu of the glass or any backing)

Thoughts?

I've got connections at a laser-cutting facility (we've cut 1.45" thick steel with less than .080" deviation!), so am thinking about trying a 8.5" disc of .020" thickness (i've got an Orion), to mount PEI to it.

Is this a waste, or useful?

PEI is expensive. You would need a thick piece at $$$. Plus, PEI is not thermally conductive so you would have a hard time keeping it hot. A thin sheet (.03' works well) glued to aluminum would be a great alternative.

However, thin aluminum is NOT going to prevent the inevitable deflection/warping of the hot bed. All PCB type of heated beds warp at temperature.

I just chatted with my buddy who sets this stuff up all the time for laser cutting.

He's saying the thinnest sheet steel should be about .0478" (18 guage), to prevent warping..

He can also do aluminum but it's significantly more pricey to source (and to cut, as it has unpleasant characteristics when being laser cut).


2 questions:

1. what is the diameter of the Max deck?
2. anybody see any possible issues with steel vs alum for a plate?


Considering the cost of thick PEI, it's FAR cheaper (I think) to cut steel disks and adhere thin PEI to them, than to do it with thick PEI. This would also help with the heat issue as well..

If this is of interest, i'll chase down some costs and get it figured out.. I definitely want to do it for myself, but don't want to have to choke up for a whole sheet of 18gauge just for one disk!


on another note, I'm thinking steel that thin is going to warp with heat, so really should be looking more at 10 (.135") or 12 gauge (.104")..


Any thoughts from the collective on this?

I agree that thin steel is going to warp as much as thin aluminum does. Which would warp more is beyond my knowledge level.
I do not see a problem using steel and if I am not mistaken, the transference of heat through steel would be better than aluminum.
I'm not sure why steel is not used more in this application except that most people prefer the looks of aluminum and then there is
the weight differential.