1y ago

Word of warning to those with Prusa MK4 and Satin beds. There is a chance that the auto bed leveler will mess up and destroy your print surface.

I've tried to report the issue to Prusa support but they keeps trying to diagnose it as user error. But at this point I'm at a loss and presume that it's either a firmware issue or a sensor issue on my unit.

Either way im very disappointed.

And before you ask, this is the opposite side

EDIT: I will note that this print sheet is ruined for my use case, since those patterns will be shown on the underside of my prints. But the print surface still works and can be used without issue... if you ignore the gouges that are being detailed into every print.

57 comments

What is going on with your flooring my guy
- Living in a 30 year old apartment for 5 years and no way to do repairs. It was liked this when I moved in.
  $1,500 CAD/Month (current market $2000) Welcome to Halifax, NS!
  
  I'd just shove some wood filler in the gaps to at least have a smooth floor even if it doesn't look great. I feel like I'd stub my toes on that shit all the time.
  
  If it's a floating click together floor...Packing tape.
  Put like 6 layers down long ways on the board with a foot or so sticking up to use as a handle.
  Hold the tape, and kick the tape where it just starts to go up. If done correctly, it will scoot the board along in the direction you kicked. Repeat until gap is now at edge of room, ideally under baseboard and invisible.
  
  Come to Onterrible, 2 houses in my small town are going for 2700++/mo 2 bed 1 bath
- Bed leveling error
- The floorists forgot to enable Linear Advance.
I just had to read up on the MK4 because I don't own one. Apparently this machine uses a load cell on the bed to detect the nozzle touch? That means that to home Z or mesh level the bed, the nozzle has to touch the build surface. This strikes me as a rather bad idea. I can think of tons of situations such as a pointy diamond or ruby nozzle, a very hot nozzle, or a nozzle with hardened crud stuck to it all causing damage to the print sheet, not to mention the potential for damage to the nozzle itself.
Ideally the nozzle should never, ever touch the print surface. For any reason.
There's a purpose behind things like the BL Touch having a soft plastic probe on the end.
- In the cases you describe it should fail by ruining the print, not the build plate though. If there is something between the nozzle and the plate, it will be too far away from it after calibration, not too close.
- Oh I've had my fair share of issues with this. i.e. little specs of the previous print color is stuck on the next print since I missed it during print clean up.
  But if I am honest, for a normal spring steel PEI sheet it's perfect. And I prefer this to the magnetic solution like on the Mini since it lets me use Garolite/G10.
  I've only seen this issue with the satin bed.
- They've stopped using the PINDA probe?
  That was the best auto bed leveling system I'd seen because it stood half a chance of ever working. The biggest problem I would see out of them was, well...the whole carriage/extruder assembly was designed by a rock chewing moron.
  I used to build and maintain the printers for a little company that 3D printed parts for their products back in the beforetimes, so I've had my fair share of Prusas apart. I don't think I could design a worse mechanism if I tried.
  The extruder mechanism was a demented sandwich of parts that don't make sense all made in shiny black plastic so it's hard to see their shapes. You don't build it up from one side to another, you build it up from the inside out. All the wires are supposed to route through a hole in the back of the carriage, then get pinched between the carriage and the extruder body in a couple channels that bend them at sharp right angles. The whole extruder mechanism is a demented sandwich built up from the inside out that doesn't let you easily remove and replace any of the working parts. ANY service to the extruder group, be it a new nozzle, a new fan, a new thermistor, is a complete teardown and rebuild, partially because there are no electrical connectors at that end, all the wires are 16 inches long and run all the way back to the main board. And the PINDA probe mount wasn't a separate bracket that bolts on, it's a feature of the largest, most central piece of plastic and it's attached by a thin little shard of plastic that WILL soften and deform in service.
  In the case of a heavily used printer, say for production or a busy prototyping lab, you can't just have a spare extruder built up ready to bolt on and go. You can't have a hot end built up on the bench ready to swap in. If one needs maintenance or repair, it will take hours, no matter how minor the job.
  It was like working on a Macbook built by BMW. I didn't charge enough for my time.
- Hey, just wanna point out that having a touch sensor built into the nozzle is definitely not unheard of, my printer (Neptune 3 from elegoo) uses the same sensor. It's not the most reliable sensor in the world but it got the job done until I got my BLTouch.
- If you're bed leveling with a heated nozzle, you're not doing it right.
  
  Shouldn't you make your adjustments while the bed and nozzle are at least partially heated, since metal expands when heated? If you adjust z-offset when cold, the nozzle may expand a bit, decreasing the gap. At least that's my understanding, and why most printers I've seen will preheat the bed and nozzle before doing bed leveling
  
  Sure, but that doesn't mean there won't ever be some situation where it'll try to Z home for whatever reason, or even if it's just user forgetfulness, and you poke the PEI sheet with a 215+ degree nozzle. The fact that the mechanism inherently includes that possibility is stupid.
Did they describe the types of user error that could cause this?
- Useing older firmware (was 1 version behind at the time of conversation), and a dirty nozzle which I clean regularly to prevent PETG globs from being deposited in my prints.
  EDIT: The newest markings on the print bed was on the latest firmware.
  
  The firmware they supplied with the printer?
If this was during an auto level, it's my humble opinion that this is a manufacturer's defect in the machine that caused the damage. There should be proper coding to ensure that any increase in sensor pressure by (delta p) halt that machine and that there should be a pressure offset in the sensor such that a loss of signal or anomalous zero reading or lack of reading is done prior to levelling to ensure that a sensor failure has not occurred. My XL freaks out if a fan isn't spinning at the right speed, so they clearly know that a nominal operational check before the print starts is proper engineering design.
Of course you won't get anywhere. Unfortunately, a lot of 3D print failures really are user error so I suspect that's their default response and it takes them a good deal of proof to push them of that mark.
- I 100% agree, however I went Prusa for their replacement parts and long term support of said parts. Rather than their quality which outside of the bed levels on uneven surfaces has been good.
  
  Oh, I didn’t mean to come off as dissing Prusa in general. I ponied up for an XL and it’s night-and-day better than any previous printer I’ve owned.
Oof that's rough. I have marks on mine from bad 1st layer offset from the first time or so I used the sheet on my mk3s, but they're more just lightly shiny rather than gouges. Definitely show up on the print but it's fine otherwise, and honestly the spots aren't the worst.
What happened when that was going on? My experience with the voron tap a dirty nozzle would make the 1st layer offset too large and move away from the bed, not crash it.
- Exactly as you said. I call it gouging since material is being removed. But the marks aren't deep and the print surface is completely usable. Don't have a better word for it than gouging.
  As for what I was doing? Restarting a print I had to stop part way last night since the filament jammed. I looked away for a second then heard knocking from the printer and was welcomed to this beautiful new mark on my print sheet.
  
  Wow that sucks even more, I had thought there would be a bunch of crash protections built into their firmware, prusa usually has pretty decent support so sorry you're dealing with that.
I'm sorry to hear they aren't taking this seriously. I have to use a gluestick on all of my prints with my PEI sheet on my Mk4 and I've really been excited to try the Satin sheet as I've heard it's an excellent workhorse sheet for the Mk4. I'm just waiting until I need to order some prusament so I can bundle the satin sheet as prusa shipping costs to the US are steep. Hoping there is a firmware fix for this before I proceed.
- Print sheet works, cosmetically it doesn't. I sell my prints, and having odd lines is not something I want to sell. I'm just disappointed since there was nothing I can do except watch and kill it as fast as I can.
- I caution you to not put too much stock into OPs anecdotal experience. This is not a problem other people are having and is certainly not a firmware issue. I can say for certain that it has never happened for me.
- Stuff sticks to my pei sheet TOO well. Clean it well... Soap and water with a new clean soft sponge. Get all the glue off and any other gunk and oil. Wipe it dry with a clean towel. Lightly rub it down with isopropyl alcohol. When dry, print on it with nothing on the sheet. I can go like 20 big prints before I have to clean it again.
  
  Yeah I've done all the things. Things don't stick to mine. 1st layer issues. Gluestick works great. Others have reported this issue. I see no disadvantages to the satin sheet. Ive heard nothing but happiness with it. Seems like it should be the default from everything I've heard.
Now do it like 5 or 6 more times on the rest of the bed and now it's textured for extra adhesion.
So this problem is intermittent? Eep. If you're lucky enough to be able to capture a video of the full home and print start when the problem occurs then that might help; but that might be difficult.
- At this point it's not like even if I did capture it, I'd get a new print sheet. I've just switch to G10/Garolite. Had good results with it before, but switch to Satin since I wanted a print bed for both PLA and PETG that didn't destroy the Print Bed.
  
  Are you turning off the magnetic ABL, or using it through the garolite?
Dem Barney toes
Are you sure the surface is damaged, and not just some material stuck on the sheet? Looks to me just a very thin layer of material on the sheet.
- Oh I wish it was. I was even printing in clear. But sadly no it's permanent.
  
  I had a similar thing happen to my smooth PEI sheet. Forgot to change sheet profile before printing and printer made some noises during printing. At first thought that the sheet is damaged, but after several days noticed that the sheet is actually fine. The noise was the extruder skipping because there wasn't enough room for the material to go anywhere, and the lines on the sheet were just a very thin transparent layer of the material. Difficult to say from the images, but the lines seem to have the texturing intact? That implies the sheet is fine. The thin lines are difficult to remove without damaging the surface, especially because you have textured sheet, so you can't use any solvent like acetone.
I upgraded my school's MK3s to MK3.9s, and while it hasn't gouged in the actual printing area, it has left a deep mark where it first extrudes a line of filament, on all of my sheets.
My problem is kind of the opposite, I feel it doesn't give it enough squish, and I'm having a lot of adhesion issues. There is also a new cold draft in the space however, so can't yet pinpoint the issue to this.
New Lemmy Post: Word of warning to those with Prusa MK4 and Satin beds. There is a chance that the auto bed leveler will mess up and destroy your print surface. (https://lemmy.world/post/12609000)
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