How long should a textured PEI sheet last?
Hold up, why can't I paste into this message box???
I have a i3 mk 3 s+ (3.5 s+?) that I assembled in 2021, and I mostly print PETG with it. After a bout of PLA, I ran into layer adhesion issues, which I thought was weird. I washed the sheet with soap and water and that resolved it. While that was a couple of months ago, it was only a few prints ago. Well, last week I tried to print a sheet of Dummy 13 parts and had poor bed adhesion, though in the days prior I was able to print some small parts I designed fine. The parts were a failure at about layer 3 or 4; there was some kind of crash and I woke up to not much printed.
Today I washed the bed again, and tried both sides. I was trying to print a sheet of my small parts. Poor adhesion on one side and no adhesion on the other. I added some purple glue stick and it's printing fine now.
I know beds are considered consumable, does this mean this one is done? I think I have around 60 days of print time on the printer, but I'm not sure how accurate that is, nor my memory of it.
The other coincidental thing was that a couple of months ago, I refilled my alcohol spray bottle with a different brand than what I had been using. It was an Amazon brand bulk purchase, but was supposed to eb 90% or greater IPA. I use the same brand on other printer beds (Ender 3v2s, Lulzbot, and a different Prusa that I use for only PLA (I think it's a 2.5s?). I suspect this to be an equally likely culprit to a bad bed.
thingiverse.com/allanonmage
Have you been printing abrasives or white/pastel filaments? Mk3's need to have their first layer 'Z' offset re-calibrated from time to time as the nozzle wears.
Cheerio,
RE: How long should a textured PEI sheet last?
To entertain your tangent: I have upgraded it with a few things like a hardened steel nozzle and heat block from Slice Engineering. I have printed some abrasives and some glow in the dark PLA. I recently rezero'd the bed too, that was within the past year or so.
Coming back from the tangent, I'm currently printing on the side with 0 bed adhesion, all I added was the glue stick. So far 1.5 hours in and the prints look good. It's a plate of 48 of my small part, which have only a small surface area on the bed.
thingiverse.com/allanonmage
OK, you have covered the three commonest causes of poor adhesion - though check the bulk IPA purchase, some sold for certain cleaning tasks contain soaps/surfactants that cause problems when they build up.
PEI sheets usually wear visibly, the powder coat get thinner or even abrades off the steel - the smooth sheets lose chunks. It is theoretically possible that excessive wear in one small area might cause a dip where the first layer doesn't get squished enough but I've never heard of it in practice.
I've also encountered problems when the filament itself has been contaminated -- in one case a small person (not so small now) spilled milk (I think) on an open spool and rendered it unusable.
Cheerio,