Holographic Sheet
I bought a holographic sheet from Amazon and have had a few successful prints and many failed prints. I've noticed a couple of things....
Normally, I print on textured sheets. I'd say well over 95% of my printing has been PETG on the textured sheet, a small amount on a satin sheet, and an even smaller amount has been PLA. No matter what material I'm printing, or which of those two sheets I've printed on, I minimize my touching of the TOP surface of the sheet. I'll touch the bottom of the sheet with greasy fingers, just not the top. I've likely gone through more than a hundred rolls of filament in the last few years.
This has worked very well for me. If I ever have adhesion issues, I take it to the sink, wash it in hot water with a bit of spray detergent, scrub with a paper towel, and all my problems are solved. I moved into a house for a year and NEVER washed my print sheet while there. I've successfully gone over a year without washing my textured sheet and had NO adhesion issues.
Now for this stupid holographic sheet. I've had a dozen failed prints and two successful prints on this thing. I think I'm currently printing my third success. All three successes happened immediately after I washed it as described above. Yesterday, after my second successful print, I popped off the parts without touching the sheet at all, and started another print. Filament wouldn't stick.
Is this coincidence? Or is this a "trick" to using holographic sheets?
Also, I've noticed the mesh bed leveling sounds different. The Z axis makes a different sound when the PINDA is performing the mesh leveling. I occasionally hear this different sound when leveling with the prusa sheets in some spots, but it seems like the holographic sheet consistently makes this alternate sound. The sheet is flimsier, so is the PINDA just not reliably able to detect the sheet? If I can't get a good mesh leveling, this can easily explain why I'm having adhesion issues, but it still seems odd that washing the sheet immediately before printing helps.
RE: Holographic Sheet
Have you saved a new sheet profile for this holographic sheet with a new Z offset?
RE: Holographic Sheet
Yes, I did, and I also calibrated it by printing out a thin layer and adjusting the axis until my calipers measured it at 0.21mm (shooting for 0.2mm). The layer lines almost have disappeared on the first layer with it. I'm just perplexed about why stuff won't stick unless I print right after washing it. It'll take quite a few more attempts to know if washing it is actually fixing it or if it is just coincidence. I also suspect that the PINDA just can't reliably see the sheet.
If it is an issue with PINDA detection, I could probably do mesh leveling over and over in Octoprint and see how much it varies each time. I might do that this weekend.
RE: Holographic Sheet
I've never used a holographic sheet but I clean my sheets with isopropyl alcohol and a microfiber cloth between prints. If that doesn't work then you could try gluestick. If you put it on properly I think the holographic image should still be on your parts. The gluestick works for quite a few prints before it needs redone.
Other then that you could experiment with different first layer temps for the bed and hotend.
RE: Holographic Sheet
If it requires a glue stick, I'd rather send it back I think. But I didn't consider different temperatures. I'll add that to my list of variables that I may play with this weekend.
Etched holographs are ultrafine textures at light wavelength scale, the slightest surface contamination or filament residue will block them. Expect to clean the sheet after every print and I would advise a final rinse with distilled water, do not scrub.
Cheerio,