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.

 

Posted : 29/03/2020 7:08 pm
Fallon
(@fallon)
Eminent Member
Topic starter 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.

Posted : 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. 

Posted : 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.

This post was modified 4 years ago by Peter M
Posted : 11/04/2020 7:23 pm
Ron O liked
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. 

 

 

 

Posted : 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.

Posted : 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.

Posted : 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.

 

Posted : 16/04/2020 1:12 am
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