temperature, first layer height or both or back to the sink?
Sorry to flood the forum with so many potentially stupid questions, I do hope that there are still people willing to answer them...
After ironing out my PETG problems I now switched to PLA issues (I know should have started the other way round).
Settings: 215/60 degrees first layer 210/60 thereafter. First layer square was just about right with good string adhesion and acceptably smooth surface, 30 micm lower yielded rough surface.
Had one acceptable print with the same settings now three attempts generated failure as in the image. Sheet was not washed but also not touched between prints, just a bit of isopropyl alcohol.
Before I fiddle too much with various parameter, I thought I ask...
Best Answer by --:
The trick with soap and water is the rinse. HOT water, as hot as you can stand without scalding as you rinse (I hold the sheet by the edges, fingers never touching the print surface). And I rinse for minutes because I have a water softener.
Every few months an Acetone wash is needed. But I generally will do a soap and water wash after the acetone has loosened the oxides and been scrubbed around a bit.
That said: the smooth sheet has the best PLA adhesion. The textured sheet, not so good. Many have decided to avoid PLA on the textured sheet, it just has problems sticking.
RE: temperature, first layer height or both or back to the sink?
Detergent and hot water are your best friend, wipe with paper.
PLA may have trouble attaching properly so it is important that your Z level is properly adjusted.
From your picture it looks like the Z level is a little too high.
Bear MK3 with Bondtech extruder
RE: temperature, first layer height or both or back to the sink?
Thanks, maybe I should place the printer next to the sink, giving the sheet a wash every second print is a wee bit tiresome. Is there no better way?
I triple checked the dish washing liquid three times for hidden contents that might leave fatty residue and there is nothing in it that might be causing this.
In the meantime I got three attempts to start properly (frshly washed sheet and smooth sheet) but they failed at about 9 of 18mm build height buy coming off the sheet. I will try to lower the z-height a bit more and use an even wider brim.
RE: temperature, first layer height or both or back to the sink?
The trick with soap and water is the rinse. HOT water, as hot as you can stand without scalding as you rinse (I hold the sheet by the edges, fingers never touching the print surface). And I rinse for minutes because I have a water softener.
Every few months an Acetone wash is needed. But I generally will do a soap and water wash after the acetone has loosened the oxides and been scrubbed around a bit.
That said: the smooth sheet has the best PLA adhesion. The textured sheet, not so good. Many have decided to avoid PLA on the textured sheet, it just has problems sticking.
RE: temperature, first layer height or both or back to the sink?
So many people seem to have issues or just don't know what a good first layer should be. I decided to made a video today showing how to adjust the live Z to get a good first layer. Hope this helps.
https://www.prusaprinters.org/prints/20306-first-layer-calibration
RE: temperature, first layer height or both or back to the sink?
@gkmakeit -- Nice video ... I call the artifacts from being too low "ridges" ... where the nozzle is plowing or scraping the extrusion.
Thanks for posting.
RE: temperature, first layer height or both or back to the sink?
The trick with soap and water is the rinse. HOT water, as hot as you can stand without scalding as you rinse (I hold the sheet by the edges, fingers never touching the print surface). And I rinse for minutes because I have a water softener.
Ah, that might have been part of the problem, will give the HOT rinse a go, so far I have only used cold water. That might have left too much of the detergent on the sheet.
RE: temperature, first layer height or both or back to the sink?
Hot water wash is an as-needed thing. I give mine the treatment maybe once a month.
IPA squirt (never let the towel touch the dispenser) every couple of prints.
Hard to emphasize enough - I really like IPA in a squirt bottle. Towel touching an IPA bottle just transfers grease to the IPA.
And use a decent percentage IPA. 91% minimum. I use 99% (Walgreens).
RE: temperature, first layer height or both or back to the sink?
The first print after the hot wash is just printing and so far it looks ok. The interesting bit will be the one after that as this was were the problems started. Freshly washed sheet printed ok. 100% IPA from spray bottle wipe in between ruined the effect.
And thanks to gk for the video, that confirmed that my first layer is definitely good.
RE: temperature, first layer height or both or back to the sink?
So many people seem to have issues or just don't know what a good first layer should be. I decided to made a video today showing how to adjust the live Z to get a good first layer. Hope this helps.
https://www.prusaprinters.org/prints/20306-first-layer-calibration
First tell the firmware which sheet you have mounted (smooth or textured) the last Z setting you set will be stored by the firmware for that sheet.
You need to repeat this process for each different sheet type you use. The physical thickness of the textured sheet is thinner than the smooth sheet.
Never ever mislead the firmware about which sheet is current. That can dig trenches across the sheet - or print in the air.
Thanks @robert-rmm200
RE: temperature, first layer height or both or back to the sink?
I never use alcohol... it just takes oil from my fingers and deposits it on to the sheet. Unless you use gallons (equal to a water rinse/dilution) or gloves or a towel so large the alcohol never touches your fingers - alcohol will dissolve the oils on your fingers and then wick that oil to the sheet. It is just the simple physics of fluids.
RE: temperature, first layer height or both or back to the sink?
btw the really HOT rinse did the trick, should have read the washing hints properly to begin with.
Thanks guys for your patience!