Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate
 
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Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate  

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Fallon
(@fallon)
Eminent Member
Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

I'm able to get prints & z height properly tuned on my Prusa mk3, now mk3s. Mostly PLA there & all the usual cleaning stuff.

However on the newish Prusa powdercoated plate I'm unable to get any consistent bed adhesion. I'm mostly only trying PETG here. Clean it with 90% isopropyl, wash it with unscented degreasing dishwashing soap, dishwashing soap + a green scotchbright pad. I let it dry on the heated bed for a bit if it got wet.

The smooth sheet generally takes about a -.500 offset. Even after properly re-calibrating when switching plates, I've tried -.400 to -.630 on the textured sheet with all vary from bad to worse. It generally seems like the PETG wants to stick to the nozzle & once that starts it just gets worse most of the time collecting all extruded material. I've got an hardened E3D Nozzle-X these days. But I was having similar issues with a stock brass nozzle last time I tried fighting with the textured sheet last year.

These are some of the best calibrations I've managed to get & they are generally unusable.

Powdercoated bad print Bad adhesion on textured plate

I just tried drying the PETG in the oven at 160f for 4 hours. No luck. I finally went back to the standard build plate with the dried PETG & got a good temperature tower (I manually broke it checking for layer adhesion at the various temps). It's been a while since I messed with PETG & was uncomfortably close to over-adhesion on the bed due to cleaning it with soap, scotch-bright then alcohol. Easy enough to fight that with Windex or not cleaning the bed as much though.

Good temp tower from smooth PEI plate

Any suggestions on what I might be doing wrong? I'm almost to the point of trying glue stick or the like, despite all the official Prusa documentation saying it's not needed or recommended.

 

Veröffentlicht : 29/03/2020 7:08 pm
Fallon
(@fallon)
Eminent Member
Themenstarter answered:
RE: Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

Oh, an I know it's always going to be stringy as PETG. I can deal with a little stringy if I can get a decent first layer to stick. Either live with it & post process with a mini-torch and/or tune my settings a bit.

Veröffentlicht : 29/03/2020 7:10 pm
Doticus
(@doticus)
New Member
RE: Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

I'm having the same issue with PRUSA PETG  and a new textured plate. Cleaning doesn't help. Adjusted live Z and can't get it to stick. 

Veröffentlicht : 10/04/2020 7:36 pm
Peter M
(@peter-m)
Noble Member
RE: Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

3D printer first layer problem | Calibration process

This how it should look like, see movie.

Clean bed 2 or 3 times with dish soap, this is very important, no alcohol needed.

First layer , most users need to go lower if it fails.

Clean nozzle so filament can not stick to it.

This normally not needed, but you if it still fails:(if you need this then your settings are not good)

First layer speed, go slower.

Extrude hotter for the first layer.

PLA sticks not good to the powder coated bed.

Diese r Beitrag wurde geändert Vor 5 years von Peter M
Veröffentlicht : 11/04/2020 7:23 pm
Ron O gefällt das
Doticus
(@doticus)
New Member
RE: Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

I was able to make some progress with prusament petg galaxy black and the textured print sheet.  In my case, the cleaning made only a small difference.  Temperature and live Z value were biggest issues.  My thoughts:

Problems:

1) material has small reflective particles so it is very difficult to see layer quality 

2) the first layer calibration routine in firmware is too short to accurately set the live z value.

3) the fist layer calibration routine runs only at 230C while this filament says to use 250C =/-10C.  I couldn't find any adjustment to this.

4) I had no idea how much difference to expect in the smooth sheet vs textured sheet live z value.  

Solutions:

1) posted elsewhere is a 75mm x 75mm single layer Gcode file from JeffJordan.  This gives you lots of time to adjust the live z.  

2) I edited the file to use the proper temperatures for petG

3) I made a methodical changes of .050 using his method until I found the best value.  In my case, the smooth sheet live z value is -.717 while the final value for the textured sheet was -1.05.  This delta may give you a target to work with.

Afterwards, the adhesion was much better. 

 

 

 

Veröffentlicht : 14/04/2020 3:15 pm
marcus.k6
(@marcus-k6)
New Member
RE: Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

I got the same kind of problem. PETG was ok, but PLA didn't stick.

When I increase bed temperature by 10°C for PLA it worked fine.

Veröffentlicht : 14/04/2020 4:02 pm
Ron O
(@ron-o)
Active Member
RE: Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

@peter-m26

I had tried to calibrate for the textured sheet using Prusa calibration and PLA I got it calibrated but when I tried to print something it would not stick.

I assumed you shouldn't use scotch brite on powder coat, but that's what did the trick for me.  Washed it with Dish Soap and Water using Scotch Brite , then ran your g-code using (two year old) E-Sun PETG with the Live-Z settings I had from before.  Stuck like glue (well, not quite) but it stuck.  Thank You

Peace, Love & Applesauce.

Veröffentlicht : 15/04/2020 3:31 am
Peter in Katy
(@peter-in-katy)
Estimable Member
RE: Unable to get PLA or PETG to stick to a Prusa textured powdercoated plate

The difference in Live-Z for me between smooth and PC sheet is ~0.300mm.  PC has the larger negative number.
You imply that your live-Z is roughly the same.  When I run on the PC sheet without changing it in settings, i can't get anything to stick either.

 

Veröffentlicht : 16/04/2020 1:12 am
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