Notifiche
Cancella tutti

Prints lifting from textured bed  

  RSS
Tanner
(@tanner)
Active Member
Prints lifting from textured bed

Hi everyone,

First-time post here. While I haven't printed in a few months, today I've gone back to it only to find that going back to the original settings in SlicrPE hasn't fixed the issue I've been experiencing since before I took a break from printing.

I have the textures spring-steel sheet on my machine and the rest of the machine (i3 Mk3) has been left as is since I got it (build and shipped to Canada from Prusa, not a kit). My main issue is that my prints lift off the bed, ultimately getting pushed around and cause the rest of the print to fail. This happens with Prusament PLA, Hatchbox PLA, and Makerbot PLA. Originally my Z-height was bumped up so I had reset back to -0.855 and that helped. But by the time it has completed 2-5mm (regardless of layer height), it has pushed a part of the print off the bed and it fails. I've gone back to the sample g-codes that came with the printer and they fail as well. The printer worked like a charm for the first 4-6 months and then this issue started happening and no matter how many settings I tweak - whether its extruder temp, bed temp, bed speed, retraction speed, etc etc), it's like the print and the nozzle get caught on each other and ruin the print.

I'm assuming I don't have to use stick glue with the textured sheet, but is there anything I'm missing? Is -0.855 too close to the print bed for the nozzle?

Any help would be great as I have an urgent project to print required over the next week.

Thanks,
Tanner

Postato : 27/03/2019 11:54 pm
JBinFL
(@jbinfl)
Reputable Member
Re: Prints lifting from textured bed

A first step is to ask, have you cleaned your bed with a dish soap wash and rinse?

Washing the sheet in the sink with dawn dish soap and water and not touching it except by the edges is the initial point for adhesion issues... The second post in this thread has a very good summary for instructions on that. https://shop.prusa3d.com/forum/assembly-and-first-prints-troubleshooting-f62/flow-and-or-bed-adhesion-problems-t28606.html

Then, what does your first layer look like? Pictures would be helpful to assist to see your first layer. The life z adjust thread will provide good info in the first four pages that will show you what a first layer should look like. https://shop.prusa3d.com/forum/assembly-and-first-prints-troubleshooting-f62/life-adjust-z-my-way-t2981.html

Since it was a factory assembled printer with prior good prints, the assumption that it is related to a mechanical problem is less likely but possible. Finally, drafts and temperature issues can cause adhesion issues, but the dawn dish soap wash is the first step, then a good live z layer is next.

Strange women, laying in ponds, distributing swords, is hardly a basis for a system of governance!

Postato : 28/03/2019 3:19 am
Tanner
(@tanner)
Active Member
Topic starter answered:
Re: Prints lifting from textured bed

I have not washed it with dish soap. I had wiped it with a 99.9% isopropyl alcohol wipe but the problems had started prior to that wipe. I've tried wiping the sheet a number of times since then as well. One thing I've noticed about many of these adhesion issue threads is none of them discuss the powder-coated textured sheet.

Nevertheless, the first thing I did this morning was wash it with warm to hot water, dish soap, and made absolutely sure I would not touch the print area. I went back to the manual as well in looking for adhesion issues and Live Z tweaking and re-learned that the Prusa logo in the samples was a good print for tweaking the Z-level. I brought the nozzle even closer, from -0.855 to -0.925 and that seems to have helped. Image 1 is from the Prusa logo at -0.925, Image 2 shows the failed print brim at -0.855. I know the second image of the crappy brim is hard to see but up close, there is a noticible difference. So far its fared better than anything I've printed since ~October-ish. Image 3 shows the side by side of the bottoms. Left is the Prusa logo, right is the fail print from last night before the original post.

Postato : 28/03/2019 1:05 pm
RH_Dreambox
(@rh_dreambox)
Prominent Member
Re: Prints lifting from textured bed

On picture number 2 you can see that the Z level is still slightly too high.
There should not be any slots on your first layer, so lower the Z-level a bit, for example to -0.940.
The surface should be glossy and smooth. If the surface becomes dull and uneven then the Z level is too low.

Bear MK3 with Bondtech extruder

Postato : 28/03/2019 3:12 pm
bobstro
(@bobstro)
Illustrious Member
Re: Prints lifting from textured bed

The on-board Live-Z calibration routine can be a bit difficult to interpret. I recommend Jeff Jordan's excellent "Life Adjust" routine. It is much easier to use and understand.

I recommend starting high (less negative) and working your way down (more negative). Initially, lines may not adhere at all. Keep going lower in large increments (0.10mm) until lines start to stick. Go lower in smaller increments (0.02mm) until you get good, even 1st layer lines with no gaps between extrusions.

When you've got your Live-Z setting adjusted properly, you should not be able to move single-line extrusions with a gentle poke. They should adhere enough to require a bit of a push to pop off.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Postato : 28/03/2019 3:41 pm
Tanner
(@tanner)
Active Member
Topic starter answered:
Re: Prints lifting from textured bed

Thanks for the answers. I'll look into reducing the Z-level a bit more and do another prusa logo print in doing so.

Postato : 28/03/2019 5:55 pm
JBinFL
(@jbinfl)
Reputable Member
Re: Prints lifting from textured bed

Tanner:

Right on! glad you are getting it sorted. Bobstro's post has a link to his website in it and he has produced and accumulated invaluable info - bookmark it - it saved me from a lot of issues and has reference info that is top notch and easy to understand (like some other high post count posters on this site).

The Prusa logo is a good idea for first layer calibration, but you have to cancel the print after the first layer so as not to waste filament... The referenced life z thread also contains example first layer cal squares, as does Bobstro's site and if you search my prior posts by clicking user posts in my username I posted an some too. They are STLs and customizable, so you can create Gcodes for whatever filament temperature etc you need...

My perspective is that it seems that after the first few prints, a buildup of contaminants appears on the sheet which requires soap and water to wash off before you can continue successful printing. Dawn and water with a clean paper towel is the first step with adhesion issues. Make sure to dry with a clean dry paper towel and do an alcohol or windex (for PETG) wipe and you should be good to continue.

Edit: All I print on are PC sheets and the above info works for all of them.


Thanks for the answers. I'll look into reducing the Z-level a bit more and do another prusa logo print in doing so.

Strange women, laying in ponds, distributing swords, is hardly a basis for a system of governance!

Postato : 28/03/2019 11:31 pm
Tanner
(@tanner)
Active Member
Topic starter answered:
Re: Prints lifting from textured bed

I must say, I regret not posting my issues sooner. While I did let the print finish the logo, I've decided to keep the Z-level at -0.935.

Moving forward I'll be sure to stress the importance of not touching the build area to my co-workers (and myself), continue wiping the area with the alcohol wipe every once in a while and same for the warm water/soap wash.

On the side note of drafts and temperature, I work in an office environment and keep the printer at my desk. To help keep drafts down, I've repurposed a mail tray as a wall to help block drafts from people walking by. The office temperature doesn't fluctuate too much either and I try to keep printing to a minimum between 9a to 5p unless its for a project. Hopefully in the future I can get a proper enclosure built for it though.

Thanks again everyone for your help!

Postato : 29/03/2019 12:25 pm
Forest Laflamme
(@forest-laflamme)
New Member
RE: Prints lifting from textured bed

Just a note on water usage..  The " https://blog.prusaprinters.org/how-to-print-on-a-powder-coated-sheet/ " web page states never to use water on TEXTURED sheets : 

"Also, the powder-coated sheet is not waterproof. When exposed to high humidity, it corrodes and loses its properties. Therefore, do not clean the sheet with water. It is possible to do that only if you have truly tried everything mentioned and your objects still don’t stick to the surface. It could mean that you have sugar-based compounds on your sheet that can’t be dissolved with IPA."

 

I'd use water and bit of soap as an absolute last resort IF I suspect contamination from a sugar-based compound..

Postato : 09/09/2019 8:21 pm
Dave Avery
(@dave-avery)
Honorable Member
RE: Prints lifting from textured bed

if you have printed PLA you will have sugar-based compounds....

water wash if really fine as long as you dry the sheet with clean paper towels and then heat it for a final dry ( using the heat bed )

the "rust" risk is if you were to wash it , not dry it and leave it off the printer to air dry

Postato : 09/09/2019 9:08 pm
Forest Laflamme
(@forest-laflamme)
New Member
RE: Prints lifting from textured bed

Because you print PLA doesn't mean it will stick there and contaminate the sheet, this would be a very rare issue 😉

 

Postato : 09/09/2019 9:38 pm
JBinFL
(@jbinfl)
Reputable Member
RE: Prints lifting from textured bed

Washing the PC sheets with dish soap and rinsing in water is not something that will hurt the PC sheet if done with caution, infrequently, and dried afterwords.  I have read the blog post and think that is a precaution by Prusa given the numbers of sheets out in the wild and the murphy's law effect given that they cannot control how the user washes the sheets.  That blog post was in June of this year, as was the user manual.  Prior versions from 2018 and before actually said to wash the sheets...

The sheets are powder coated which is an impermeable coating that they apply to car bumpers and outdoor furniture and such so the lack of waterproofing claims are in my view overblown.  Now, Acetone does seem to damage the PC sheets so never use acetone on them. 

I have and use 5 powder coated sheets for over a year and have washed every one without ill effects and so have many others.  The key is to use the water judiciously, by having it running from the tap to just to rinse the dish soap (which is the real cleaner) off  like washing an expensive kitchen knife after use and to dry it afterwords. Don't let the sheet sit in a pan of water or put it in the dishwasher or anything for God's sake!

I even wash the sheets when switching between PETG which I use Windex on and PLA which I use IPA on in order to remove it.  If it was not washed, I am not sure how the IPA would remove the windex and PLA would never stick.

Bottom line, if you cannot get PLA to stick, scrub the sheet with a piece of clean, white, ( no dyes ) paper towel (wet) and with a bit of plain Dawn or Palmolive dish soap (no additives or weird scents or moisturizers or anything) on both sides and handle only on the edges.  Rinse under a running sink to get the soap off, and dry with 2 or 3 clean dry white paper towels on both sides and put on the heatbed and wipe with another piece of paper towel with either 91% IPA for PLA, or windex for PETG, and heat up and print.  you will not have problems.

Strange women, laying in ponds, distributing swords, is hardly a basis for a system of governance!

Postato : 13/09/2019 12:24 am
rmm200
(@rmm200)
Noble Member
RE: Prints lifting from textured bed

If you have time - and can afford it - get a PEI sheet also. It will cause you far less grief with PLA.

Save the PC sheet for PETG, and use it for PLA if you want the textured bottom. And expect to use brims - often.

Note: Keep PETG away from your PEI sheet. It sticks too well.

Postato : 13/09/2019 12:38 am
Condividi: