PEI Bed Surface

[kazolar]

I've never needed ABS juice. Just normally have to adjust tbe z to squish more than PLA or PETG it works fine at 95, I've done a box nearly the size of the bed on the M2 with no lifting, also out of hatchbox abs (white). I've never went about 95c. The point with PEI is that you should not need any juice or other mess...move your z a hair closer, sometimes a 1-2 layer, 4 outline is good to use with big abs parts. Thats what James Bruton normally does, and he prints a tone of abs

[pyronaught]

I gave PEI another chance and decided to switch all machines over to this. I just got tired of kapton bubbles and wiping the slurry, and PLA doesn't stick to kapton as well as it does PEI. The nice thing is you can switch between all different kinds of filament on PEI without having to clean the plate. With ABS slurry on kapton, it takes quite a bit of acetone washing to get all the slurry off when moving to PLA. Part of my PEI adhesion problem was also due to not having a clean surface. After I started wiping it with alcohol each time I got much better results.

I'm curious how people are trimming the excess around the edges on this stuff. This is one hell of a touch material to cut! I have a system that works good, but it requires using a metal sheer that most people probably don't have so I'm curious how others are doing this. Even with the sheer and its 30" long lever it takes a good bit of force to get a cut going. I sheer it to within 1/8" of the glass and then belt sand the final excess to get a perfect edge.

[Jules]

I use a plastic cutting knife. (you score it by dragging the bottom point across the plastic, and snap it off.)

https://www.amazon.com/Hyde-Tools-45730 ... ting+knife

It's also handy for getting that first corner pried up, if you are careful with it.

[pyronaught]

Ah. I think I must have done my first PEI plate that score-and-snap way and just forgot about it. I can't imagine cutting it any other way other than the big sheer I'm now using.

[zemlin]

I cut mine on a table saw. It isn't an exact match for the MIC6 plate, but it's close. I've thought about cleaning up the edge with flush trimming bit in a router.
https://www.zoro.com/bosch-router-bit-c ... lsrc=aw.ds

[pyronaught]

The nice thing about cleaning up the edge on a belt sander is that it doesn't matter if you hit the glass. The glass will actually sand and spark a little, but you're not going to crack it with a sander. A router bit coming into contact with the glass would likely not end well.

[Jules]

Chuckle! Sandpaper. Plain old 1000 grit sandpaper. Cleans it up in under ten minutes. (It takes longer than that for me to pull out the machinery to do it for me.)

[pyronaught]

1000 grit? I think you are talking about sanding the surface. I hand sand using 1200 grit for that too. In the previous message I'm referring to sanding the edge after trimming the excess PEI. I have a benchtop sander with a belt surface that is as long as the glass edge, so I can sand the entire edge at once. I did score-and-snap on my first plate, but I seem to recall it wasn't very easy and there's always that risk the crack is going to wander outside the scored line when you break it. Shearing it was much easier, although still surprising how much that material resists being cut. As a build surface I bet it never wears out, but I suppose the glue layer underneath is what eventually loses its grip. I hope it lasts a long time though, as I bet trying to remove the glue is very difficult and you probably wind up scrapping the PEI surface in the process.

[Jules]

Nope - I use a 1000 grit to just clean up the very edge, which tends to be a bit sharp, and the corners. (I get a nice clean break with the plastic cutter - it doesn't require heavy material removal.)

But you can always start coarse and go finer if you get a spot that didn't break cleanly. (That did happen on the first one - wasn't sure how to use the cutter.)

[ajmadison]

Not sure who exactly recommended using a high grit number sandpaper, but wanted to thank that person, and provide some positive feedback. In an act of desperation, i had shot some hairspray on my zebra plate, and the surface lost all adhesion, esp. for PLA. Thought I'd ruined it. I took some 600 grit paper to it, and though it felt as smooth, if not smoother than before, I did a test print, and PLA stuck to it as good, if not better than before. So sanding the PEI works. Thanks all around.