Welcome to the SeeMeCNC Community

I'm really impressed with this PEI. Here is my story:

I've been using build-tak which has been a nice material to print on but sometimes the prints get really stuck to it and the removal damages the surface. I went through 2 of those at $25/ea.
I heard about PEI here so I thought I'd give it a go.

I purchased a square on amazon (http://amzn.com/B0013HKZTA) for $17. It came in at 30 mils or .03" thick. I slipped it onto the bed with the clips and tried a print which failed miserably which I expected it to do.
So I looked into taping it down. The stuff to get is called 3M 468MP (http://amzn.com/B007Y7D5NQ). It's heat resistant and holds really well. A bit pricey though, at $23 for 6 sheets. I didn't order that yet , but thats apparently the thing to do. I will order that when my current PEI wears out. I also needed to cut it round somehow.

So I looked around the internet for some PEI that was round with tape already attached. And I found a place that sells it just like that. http://www.cshyde.com It was really thin though.
I asked them to cut me a round and they responded quickly.
The 3 mil. at 11” diameter wa $14.09/ea. The 5 mil. was $25.00/ea.
I took a chance and got the 3 mil. It came in about a week. I pulled the backing off and pressed it onto my freshly cleaned glass and ran a PLA print @ 55º (after resetting Z).

I was amazed! Everything stuck very well. The corners had 0 lifting. The finish was very smooth. I tried pulling the print off right away and it wouldn't budge, so I waited for the plate to cool, and the print popped right off! I've made 8 prints so far of different size and everything has worked like a charm. I'm very pleased. I'll update this post when I try the thicker stuff, but so far, the thin stuff is working just fine.

Yes it is amazing stuff. I have been using it exclusively for over 2 years and after 1400 plus hours I am still on the original .03 sheet.

Thanks for the link to the source of the PEI that you purchased.
Having the adhesive already on the PEI could solve a lot of problems.

I debating between this or an aluminum heat spreader as my first upgrade....

Q, I would do both, and attach the PEI to the heatspreader (Presuming it's flat an unwarped.), which will make your sensed temperatures more accurate to your surface temp.

I agree, PEI is amazing ! I am a late adopter, just upgraded last week with the same sheet from Amazon . Having great results with Abs at 90 degrees. I had been ripping up pieces of glass with Abs juice and couldn't do it any longer. I actually installed the PEI on my chipped up bed and it's working great, the PEI is actually bridging the divots left in the glass bed. No problems so far ..

Agree PEI rules!!! 1.5 years of printing with it and agree with all comments above.

I just received a PEI sheet from http://www.cshyde.com part# 36-10A-3D its 12.2" in diameter, I have not installed it yet.

If am going to use dc42's IR z-probe should I scuff the surface with some 600grit or use as is?

CodonExe wrote:I just received a PEI sheet from http://www.cshyde.com part# 36-10A-3D its 12.2" in diameter, I have not installed it yet.

If am going to use dc42's IR z-probe should I scuff the surface with some 600grit or use as is?

DC42 recomends painting it with barbecue paint first on the underside, then bake it. You can see his process here: https://miscsolutions.wordpress.com/201 ... e-roundup/

Thanks Xenocrates! This particular PEI sheet has the adhesive already applied so there is no way of treating the sheet from the bottom. I may need to just order some without the adhesive.

CodonExe wrote:Thanks Xenocrates! This particular PEI sheet has the adhesive already applied so there is no way of treating the sheet from the bottom. I may need to just order some without the adhesive.

Here's the kludgy fix then. Once you have the PEI installed (And make sure it's on a non-IR reflective surface, such as painted aluminum or polycarbonate), you can adjust the angling of the diodes such that it triggers when the end is on the bed. If you haven't bought the IR probe yet, I'd recommend FSR's, as they don't need adjusting for bed materials, nor do they add mass to the effector or wiring to the harness, and allow you to swap things quickly and easily.

Xenocrates wrote:

CodonExe wrote:Thanks Xenocrates! This particular PEI sheet has the adhesive already applied so there is no way of treating the sheet from the bottom. I may need to just order some without the adhesive.

Here's the kludgy fix then. Once you have the PEI installed (And make sure it's on a non-IR reflective surface, such as painted aluminum or polycarbonate), you can adjust the angling of the diodes such that it triggers when the end is on the bed. If you haven't bought the IR probe yet, I'd recommend FSR's, as they don't need adjusting for bed materials, nor do they add mass to the effector or wiring to the harness, and allow you to swap things quickly and easily.

Oh I see, your changing the trigger level so that it will compensate for the PEI/adhesive thickness.

I only purchased one IR probe and installed it on one of my hotend assemblies, I wanted to see how it worked with the boro-glass and PVA glue before I added it to my whole set.

Will the 3-point FSR's allow me to map my build surface like a z-probe?

CodonExe wrote:

Xenocrates wrote:

CodonExe wrote:Thanks Xenocrates! This particular PEI sheet has the adhesive already applied so there is no way of treating the sheet from the bottom. I may need to just order some without the adhesive.

Here's the kludgy fix then. Once you have the PEI installed (And make sure it's on a non-IR reflective surface, such as painted aluminum or polycarbonate), you can adjust the angling of the diodes such that it triggers when the end is on the bed. If you haven't bought the IR probe yet, I'd recommend FSR's, as they don't need adjusting for bed materials, nor do they add mass to the effector or wiring to the harness, and allow you to swap things quickly and easily.

Oh I see, your changing the trigger level so that it will compensate for the PEI/adhesive thickness.

I only purchased one IR probe and installed it on one of my hotend assemblies, I wanted to see how it worked with the boro-glass and PVA glue before I added it to my whole set.

Will the 3-point FSR's allow me to map my build surface like a z-probe?

Yes they do. They act pretty much precisely like a Z probe, due to the JohnSL board. There are some points where it isn't perfectly even, but that can be compensated for with the H values on the individual points, and you don't have even the minimal offset from the probe not being the nozzle. It's really quite clever.

for some reason my ABS doesn't seem to want to stick really well to the abs... I keep trying to print a part with some chamfers pointing down toward the bed and it keeps curling/lifting. It's a large piece.. but I can't get it to print. In fact, my results are worse with the pei than they were with abs glue...

Do y'all think it just impossible to print with the chamfers pointing down? The calibration pattern prints pretty nicely...

I got a a 5mill pei sheet from chyde...

How long have you had the PEI? I find that for large ABS prints it is basically essential that I sand the sheet with 600 grit sandpaper beforehand to make the sheet completely smooth but matte. It gives the surface a grippy feel to it. Give that a shot, and make sure you are erring on the side of too low rather than too high for the first layer.

Chamfers on the bottom face are really tough with the materials that contract more. There's extra material, further out, just above the surface and trying to pull the overhang up and in. Heated chambers help a lot. I've also had some luck running an extrusion width or two down at an angle to brace the face in critical areas (kind of like the mickey-mouse ears people put on parts to give a larger, rounded, adhesive surface further out on the part, but for parts with chamfers on the lower face), then snipping and filing the extraneous material off.

yea, I just read about sanding the pei... I didn't know you were supposed to do that... mine is very smooth.

Also, do you think increasing the bed temp to 100c will help? I heard the extrusion temp should be as low as possible, so I lowered it to 215c but I've still got some warping...I'm insid pie of a heated enclosure already

increasing the bed temp to 100c and lowering the z hight .05mm solved the warping/sticking issue. It takes about 38 minutes to reach 100c though :-/. I was trying for 110c but the rostock's heatbed isn't capable of that.... when I get the duet I'll probably go 24v for the heatbed... had to do the same thing with my Prussa.

I wouldn't recommend the stuff from chyme... I think it is just a bit too thin and with the adhesive when you scrape the build plate it bunches up cause it's thin and flexible and tears...

Think I might get the 12x12 1/8th sheet on Amazon...

Has anyone else had issues with 3M 468MP not keeping the bed attached after a while?

Mine has been on there 6 months, mostly printing ABS at 105 degrees, and now when I print a larger item it pulls the PEI sheet off the heat spreader. You can see where it's attached as well, it has a different pattern where it's stuck down firmly.

I've got some more sheets of 468 but was wondering if anyone else had this issue? Perhaps some small bulldog clips around the outside might help?

I put the heat spreader under the glass and then used the 468 to adhear the PEI to the glass. I have had no issues with lifting of the PEI off the glass and am still in my original PEI sheet 18 months later.

Thanks for that 3D-Print. Maybe I didn't do a very good job the first time. Or maybe it was due to doing a lot of printing. Who knows.

Anyway I peeled the PEI off, cleaned the plate and PEI with acetone and a scraper, then stuck the PEI back down with another sheet of 468. I've got some bulldog clips around the outside now. That will have to keep it down you'd think!

I kind of have to recant my opinion about the stuff from chyde not being any good... I think a bad calibration and cold bed resulted in lifting in some places and too low of a hot end at some parts... I got that fixed now and aside from the tears made by the bad calibration it appears to be working good... A lot easier that abs glue... I was able to print something 1/2" wide(3/4 of that was support material) by 6" long x 10" tall and it didn't come off the bed....

Here is my update: the 3 mil is a tad thin. I slowly wore it down. The damage was mostly with the scraper while removing prints. It slowly lifted the PEI from the bed, and made a bubble that was jabbed, which then tore. It had a good run, but it's time to go big time now. I purchased 5 squares of 12" square 364 adhesive (https://amzn.com/B01HP2CEG8) for $15 and applied it to my 30 mil thick PEI square sheet. Then I lay the glass on it and drew the circle. Then used a pair of stamping scissors to cut the round.
I cleaned the adhesive from the bed using turpentine and a putty knife. It took several pour and scrape cycles to get it off, but I was able to remove it. Once the bed was clean, I peeled the tape from the PEI and put it down smooth, from one side to the other. No bubbles. I'll report back how it prints!

I still haven't jumped on the PEI bandwagon, yet! I was about to last year but I came across BuildTak. It works, but it sticks too well. You end up spending a lot of time waiting for it to cool and scraping it off. Recently, all the scraping caused the center to bubble and lift. Now, it's ripped and I need to remove and replace. Guess I'll try PEI.