PEI on the Robo heated Bed

Materials needed:

12" x 12" x .030" sheet of PEI (link is to Amazon.com listing)

Some 1" x 5yd Transfer Tape (link is to Amazon.com listing) You can use other tape sizes, but make sure it is actually this type of tape.

Razor blade for trimming the sheet

Some kind of flat tool for pressing air bubbles out of the seal between the tape and the PEI sheet.

Now, once you have all of the materials, trim one side of the PEI so that it is 10" x 12". This is so that the panel will fit on the actual width of the glass bed. I used my old Robo glass bed that had chipped apart as a guide for the razor blade I used to do this and basically scored the panel until I was almost through it, then snapped the excess off.

Remove the protective film from the side you want to put the tape on.

Next, carefully line the panel with the transfer tape, leaving small gaps between each strip so that the occasional extra adhesive on the roll doesn't bunch up (and so that the tape can "flow" expand as the bed heats it, according to some posts about this process on various Reprap forums).



You'll see some air bubbles in this photo, I smoothed those out before taking the sheet and applying it to the Robo's bed.



I was off center a little bit as I set the panel on my bed, but not so far off as to make it a problem for the bed travel.

Fair warning, as soon as the transfer tape makes contact with the glass, it sticks. Make absolutely sure you're closely lined up before allowing it to touch the glass.

I was lucky and didn't fuck this up too badly, but this would have been hilariously bad if I'd dropped the panel and it was crooked.

Here's another angle.



The discolored streaks are the wrinkles/imperfections in the tape.

I'll post some pics after I fix the thermistor issues I'm currently having with the nozzles showing some 1st layer, mid print and finished print progress using this, but the test/failed print I ran last night in ABS didn't curl up at all (I just didn't take a picture for this post because it was 3 hours into a 18 hour print and I'd rather that particular thing be finished when I take a picture of it).

Anyway, for other process guides and more information on why I did this, check out the Reprap article on PEI being used on 3d printers here:

http://reprap.org/wiki/PEI_build_surface

 

A pic while I'm trying to narrow down an issue (not the thermistors, using the stud thermistors now and all readouts are working fine--just can't maintain temps at the nozzles).

 

Literally the only fans running are the hotend fans. The Part fans do not function right now (mounted, but not wired in at the RAMPS end, ends are just hanging in space in the bottom of the Robo until I decide I want to print in PLA again and finish wiring that up).

I guess I'll redo the heater cartridges, I bought a few spares the last time I got bad ones from E3D.

 

The spares I bought are also 40w. We'll see.

 

Is your Z axis skipping steps?

 

Not that I've noticed.

I did have a random "solid infill every X layers" setting on the XT print I did for the CES thing, if you're talking about the darker lines on it.

 

That's what my prints looked like when my ramps cooling fan died and my z stepper was overheating

 

I can feel the ramps fan pulling air into the case when I put my hand under the Robo's main body (checked that the other day when we were talking about whether that fan had to be plugged in a certain way), so I don't think that's an issue unless it's not pulling the amount of air it should.

 

Hmm ok just an idea. If it continues you may want to tune your z stepper current

 

So using this PEI bed means I wouldn't have to use any bonding agents like glue for adhesion?

 

Seems like it.

We'll see how it does as I test materials.

XT printed pretty well, but adhered so hard that prying it off the bed ruined the base layer (actual PEI unharmed though). You can see pics in the CES thread.

ABS test ran last night and I'll post results when I check on it when I get home from work.

 

Bunch of "adhering too well to the bed" pics.

 

strong bond eh?

 

Damn near fused to it.

Going to google what the bed temps should be for various materials on PEI. Didn't occur to me to verify first but I've been sick, so the bit about not operating machinery on drugs probably applies.

 

Another test print running.

 

Mind if I ask if there's been any update on this? I just saw a demo of PEI the other day, and loved it, but didn't get a chance to ask any questions. Is it still working? The piece I was given warped up the first time I tried it with binder clips (guess I'll try the tape next); unless have you seen it pull away from the table even with the tape applied? Did you have to modify the start height at all?

 

1) Updates are coming up sometime over the next week or so between things at work and a catastrophic electronics failure on my Robo that was recently fixed.

2) The PEI itself works great with the tape I linked in the OP. No pulling away from the bed of any kind. Still need to work out correct bed temperatures to use to hold the print while it's printing but not hold on so hard that the print comes apart during removal.

3) No modification to the start height at all if you're talking about offsets, since the printer uses the hotend tip to find the bed. I did modify the 1st layer height to be 100% in my slicer and it was helping with the print removal issue before the other issues cropped up.

Again, I'll post an update some time over the next week or so, but I think some other folks have talked about using PEI in the shoutbox (any pictures they'd be willing to post would be great).

 

you can change the the start print offset in print parameters (though on MatterControl I'd have to tinker a bit, I've been using Simplify3D to generate code for too long now), even when it uses the tip to find the bed. I've read (hersey at this point) that setting the start print a little higher makes it somewhat easier to get the print off. I'm debating picking up an 1/8" piece, to minimize the heat flex I'm getting now (I don't want to use tape, but if I gotta I gotta), and giving the ability to pull the piece off and flex it then to pop the print. My concern there is heat transfer; if enough heat would get throuth the bed and sheet (the .040" sheet I have got plenty hot, but I dunno how tripling the thickness would work).