PEI Bed Surface

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ray
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Joined: Wed Nov 18, 2015 2:46 am

Re: PEI Bed Surface

Post by ray » Mon Feb 08, 2016 8:22 pm

I understand resetting the Z stop switch, But how do I run offsets?? I am kind of new to this, Thanks Jules

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Jules
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Joined: Wed Jan 21, 2015 1:36 am

Re: PEI Bed Surface

Post by Jules » Mon Feb 08, 2016 8:49 pm

ray wrote:I understand resetting the Z stop switch, But how do I run offsets?? I am kind of new to this, Thanks Jules
No problem! We just published a complete Beginner's Guide yesterday to help newbies out - go take a look at it and see if it explains what we're doing well enough. (You can be the first guinea pig.) :D

The Z-Offset is just a method of fine-tuning the Z-Stop results, and it appears in the Calibrations section in the guide. (Or at that second link that I posted in my reply to your first post.)

Beginner's Guide: viewtopic.php?f=3&t=3342

RJD
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Joined: Tue Feb 23, 2016 3:18 am

Re: PEI Bed Surface

Post by RJD » Fri Apr 08, 2016 3:31 am

I purchased 0.03" PEI sheets on two occasions from Amazon, but both were warped. There are a few complaints about being warped via customer reviews. Are these sheets prone to being warped, or is the source hit and miss? Amazon has a easy return policy, so maybe third time will better.

ErikAkia
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Joined: Wed Apr 09, 2014 8:36 pm

Re: PEI Bed Surface

Post by ErikAkia » Fri Apr 08, 2016 4:16 am

I purchased a 12x24 sheet of the 0.03" http://smile.amazon.com/dp/B0013HJBA4 It was shipped flat in a giant box and was not warped at all. Maybe try a different size?

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Jules
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Re: PEI Bed Surface

Post by Jules » Fri Apr 08, 2016 1:55 pm

RJD wrote:I purchased 0.03" PEI sheets on two occasions from Amazon, but both were warped. There are a few complaints about being warped via customer reviews. Are these sheets prone to being warped, or is the source hit and miss? Amazon has a easy return policy, so maybe third time will better.
Couple of mine were slightly warped....when they were applied with the tape they held just fine. (That tape holds it down very well.) :)

unixadm
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Joined: Tue Mar 29, 2016 5:30 am

Re: PEI Bed Surface

Post by unixadm » Sat Apr 09, 2016 4:02 pm

I've had good luck with PEI on my Makergear M2 Rev E. I bought a Lulzbot PEI sheet for a Lulzbot Taz 5, affixed it to the top of the glass and then used a pair of sharp scissors to trim it to size after it was applied. I then sanded with 3M 2000 and 3000 grit sandpaper. I run around 245 degrees on the extruder for ABS and 105 degrees for the bed surface. I've had very good adhesion with little to no warping on large parts. Popping it off at the end is fairly straight forward after it cools down. I always clean with rubbing alcohol between prints.

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pyronaught
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Re: PEI Bed Surface

Post by pyronaught » Sat Apr 09, 2016 4:39 pm

I had to give up using the PEI surface. The gripping force was just too much of a variable with respect to temperature. I would get different degrees of holding power across the platform too-- with stronger grip at the center and less out towards the edges. So any large square part would peel up at the corners no matter what. For smaller parts that did not warp off the plate, most of the time I would have to remove the plate and put it in the freezer just to get the part off. It just goes from one extreme to the other. This hassle far outweighs the five seconds it takes to squirt some ABS slurry on a kapton bed, and with the kapton/abs you get the same strong hold across the whole plate yet the part comes off easily every time once it cools. Couple that with the fact that the thicker kapton sheets are easier to apply and it just beats PEI hands down.
Experience is what you get when you didn't get what you wanted.

kazolar
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Joined: Wed May 13, 2015 4:39 pm

Re: PEI Bed Surface

Post by kazolar » Tue Apr 26, 2016 10:54 pm

For what it's worth, I've been using PEI (same sheet) on the m2 for over a year, working great. I've been using it on my TypeAMachines S1 pro for since december when I got it, I have made huge prints with it. Using the entirety of the 12x12 S1 build plate. You have to get the level and z-height right and just enough squish, and PLA never warps. PETG also sticks really well. You have to be smarter about bed temp settings, something small in the middle of the bed -- go with 50-55 (PLA/PETG) -- a bit bigger go with 65, full bed go with 70. I have not printed ABS on the S1 in that size, but have done a very large box nearly full build plate (a Raspberry Pi doorbell enclosure) on the M2 in ABS and no warping at all, it shrunk so it was hard to merry the top with the bottom, but both were perfectly flat -- I use 90-100C for ABS depending on print size. I love the stuff so much that I bought a large 24x48 sheet for my new delta which is nearly finished. With smoothieboard auto bed compensation with a 100 point grid I've done a 300mm diameter 500mm height vase with no adhesion issues -- no warping. The delta full build volume is 490mm diameter and 685mm height (which will decrease a few mm when I upgrade from the e3dv6 to volcano)

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zemlin
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Location: Indianapolis, Indiana

Re: PEI Bed Surface

Post by zemlin » Wed Apr 27, 2016 12:38 pm

I run PEI on MIC6 1/4" aluminum. The aluminum spreads the heat around nicely.
I'm thinking about gluing the PEI to the aluminum rather than using the sheet adhesive. Material that tend to warp will pull the PEI sheet along with it - not much - it doesn't break the bond of the adhesive - but I can see a spot in the center of the part where the PEI has been pushed down into the aluminum. The result is the PEI is less than perfectly flat. It's very minor, but I do see variability in the smashocity of the first layer.

PEI melts just above 200C, so the ideal adhesive would be rock solid at 100C, and butter at 175C so I could put the platform in the oven when the PEI needs to be removed.

It looks like CA can go above 250C - and that could be tricky to use over a large surface anyway.
Looks like an epoxy of some sort might fit the bill. Very low viscosity would be good for bonding over a large area. Will have to research this a bit to see if I can find the right adhesive for the job.

kazolar
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Joined: Wed May 13, 2015 4:39 pm

Re: PEI Bed Surface

Post by kazolar » Wed Apr 27, 2016 3:03 pm

When I made my heated bed on the delta, I used Pliobond Contact Adhesive for adhering the silicone heater to the aluminum and then adhering the cork insulator to the other side of the silicone heater. I used #35 as cork is porous. For this application I'd use #25. It is solid after 24-48 hours and achieves full strength bond after 14 days. It is good up to 375F, so going above that will allow you to remove it. Pretty close to PEI melting point, alternatively acetone will dissolve these high temp adhesives, so if you need to remove it, soak it in acetone. The 3M stuff turns into jelly. I don't like using a sheet adhesive, I use 2 inch tape, it allows me to get a good bubble free application, sheet has much less control. If you see it pulling up with the 3M 468 tape, then you didn't get a clean application in the first place. I have applied PEI to my 3 printers and a friend's printer as well, it is solid, nothing pulls it up.

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