PEI Bed Surface

[Jules]

It's pretty hard to keep a large surface area print stuck down when it gets out to the edges of the bed - the heat is not as great there and PLA does tend to curl up sometimes, especially if it is thin. You might be able to try a couple of tricks to make it stick better.

One that i like to use is to squash the first layer just a little bit more....add a negative -.02 mm to your Z-Offset. Sometimes that is enough to keep it stuck down. Slow down the first layer, maybe up the bed temp about 5 degrees.

A second trick is to print a wide (10-15 outlines) 2 layer brim. (Not a raft.) The brim should be attached to the print, and it's usually pretty quick to remove, but it really helps to stabilize the edges.

[Vandal968]

My PEI has finally stopped adhering well. I've probably gotten about 150 parts off of it before it started messing up prints. I'm in a hurry (big tradeshow next week), so I just wiped the bed with glue stick and kept going, but when I get a chance, I'll try sanding the surface with extra fine paper to bring it back as others have done.

cheers,
c

[pyronaught]

It's pretty hard to keep a large surface area print stuck down when it gets out to the edges of the bed - the heat is not as great there and PLA does tend to curl up sometimes, especially if it is thin. You might be able to try a couple of tricks to make it stick better.

One that i like to use is to squash the first layer just a little bit more....add a negative -.02 mm to your Z-Offset. Sometimes that is enough to keep it stuck down. Slow down the first layer, maybe up the bed temp about 5 degrees.

A second trick is to print a wide (10-15 outlines) 2 layer brim. (Not a raft.) The brim should be attached to the print, and it's usually pretty quick to remove, but it really helps to stabilize the edges.

I would just use kapton+abs slurry before doing anything that would just cause more work. That method will hold anything down no matter how close to the edge you get. It has already proven capable of holding these large warp-prone sorting screens down no problem. I'm just giving PEI a fair chance to prove itself better if possible. Squashing the first layers is not an option, that creates thin edges around holes that undersizes their diameter, which is a bad thing when you are using the holes to sort to a specific diameter. You also get a thin flange around every bottom edge of the entire part when doing that. For the sorting screens I have to use a very exact Z-stop that does not flatten the first layer at all.]]

[Jules]

It's pretty hard to keep a large surface area print stuck down when it gets out to the edges of the bed - the heat is not as great there and PLA does tend to curl up sometimes, especially if it is thin. You might be able to try a couple of tricks to make it stick better.

One that i like to use is to squash the first layer just a little bit more....add a negative -.02 mm to your Z-Offset. Sometimes that is enough to keep it stuck down. Slow down the first layer, maybe up the bed temp about 5 degrees.

A second trick is to print a wide (10-15 outlines) 2 layer brim. (Not a raft.) The brim should be attached to the print, and it's usually pretty quick to remove, but it really helps to stabilize the edges.

I would just use kapton+abs slurry before doing anything that would just cause more work. That method will hold anything down no matter how close to the edge you get. It has already proven capable of holding these large warp-prone sorting screens down no problem. I'm just giving PEI a fair chance to prove itself better if possible. Squashing the first layers is not an option, that creates thin edges around holes that undersizes their diameter, which is a bad thing when you are using the holes to sort to a specific diameter. You also get a thin flange around every bottom edge of the entire part when doing that. For the sorting screens I have to use a very exact Z-stop that does not flatten the first layer at all.]]

Pull out your calipers and take a look at .02 mm. It is undetectable, i promise. But something that small can actually make a difference in how things stick at the far edges.

I just hate to see you having to mess with a slurry when the PEI sheet should be quite capable of holding on to whatever you are printing without the bother. You might just still need to fiddle with your settings a little bit until you hit that sweet spot. Looks like you're pretty close.

And if all else fails, I'm pretty sure you can just use a glue adhesive on the PEI sheet. I've never had to, but it's an option. (Don't know about ABS slurry though, that might damage it. I'm thinking gluestick or hairspray if you must.)

[pyronaught]

Having to revert to hairspray or gluestick on PEI would defeat the whole purpose of using it and would be a step backwards from ABS slurry. ABS slurry is cheap, goes on super fast, doesn't leave residue on the machine, creates a very thin layer that doesn't leave anything on the part, gives consistent results every time and has a super strong hold. It's a lot easier to get setup with than PEI too.

[Jules]

Having to revert to hairspray or gluestick on PEI would defeat the whole purpose of using it and would be a step backwards from ABS slurry. ABS slurry is cheap, goes on super fast, doesn't leave residue on the machine, creates a very thin layer that doesn't leave anything on the part, gives consistent results every time and has a super strong hold. It's a lot easier to get setup with than PEI too.

As long as you're happy with it.....

[creativedex]

i am going to cut up my 1/4" peice of scrap 2300 pei this weekend...i think i can make two build plates out of it. I plan to use it like i do my mic6 or the zebra plate and clamp it right on the anodized aluminium.

it is a bit thicker then 1/4" maybe closer to .275 there is a rough side and a smooth side...and is very stiff. it is thick enough that i am a little worried how it will conduct heat... see how it goes.

innkeeper, you and I must have found the same source! been printing on mine for a couple weeks... ive tried sanding it to several grits and have settled on 2000 on one side and 220 (until the paper feels smooth) on the other... the plate does warp a bit which makes me think thinner is better because its difficult to correct but after heating it up to 110 and flipping it over and doing the same it seems to have stabilized it a bit... on the rough side with formfutura petg it sticks pretty well but thin parts will still warp a bit but with glue stick it worked really well... too well on large surface area parts. Have not tried ABS yet... tpu needs to be on the smooth side! for some reason it sticks so well that if its not smooth it pull tiny bits of the pei off that can show up in future prints, in short the first layer sticks better to the pei then it does to itself! seriously even purging the extruder of tpu from 8 inches up will stick to the bed! also ive found that when using tape on the pei it sticks better then on glass (previously my biggest issue with tape was it not sticking to the glass) biggest draw back of the thick sheet is that it warps and dont like to be held down well. My first thoughts were that the glass in the pei would make it more stiff but it doesnt appear that there is actual glass fibers or twill in the sheet so my guess is that its very short stranded or powdered, though it does transmit the heat well! not sure it was worth the huge cost and hours of labor to get working but it works better then tape. i do like the fact that i can sand it down more if needed after difficult to remove prints leave marks

[innkeeper]

innkeeper, you and I must have found the same source!

lol most likely...

i cut mine this weekend and have been working on the warping....so i haven't even got to print on it yet,... the warping is pretty significant. heated it up to 100, and flipped it after a bit, and still warped the other way..
i need to let it sit for a bit see if it stabilizes..i am thinking it is not a better solution over a thin piece laminated on glass or some other substrate as was my hope.

[ray]

Hello

I added PEI that is 0.06 in thickness to my build plate. Using the Simplify3D software I then went to Bed leveling wizard to lower the Z axis the thickness of the PEI and the level looks perfect. Here is when the problems start, when I go to print, the Z axis seems to go back to the default settings and hits the build plate....... Can someone please help??? Thanks in advance,,,,

[Jules]

You need to re-set the Z-stop, and then run a few Z-Offset calibrations. (The level shouldn't really change, but the gap sure does when you apply PEI.)

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