First layer Hell - MK3 now FUBAR  

Re: First layer Hell - MK3 now FUBAR

Have you heated it up and checked to see if your nozzle is loose? Mine was coming loose and caused all kinds of strange issues.

Re: First layer Hell - MK3 now FUBAR

First those ripped ones look as your live Z is too negative. Also are all those rectangles printed on the same part of the bed. If not there may be a bed levelling issue.

Regards,
Martin

Re: First layer Hell - MK3 now FUBAR

@alien.m2, will check that out. Thanks for the tip.

@martin.w15, They were all printed in the centre. There's been a definite deterioration, and all the ways I sorted things out before no longer work.

I installed Octoprint, and the mesh levelling plugin, but have no idea if this is a problem, or what to do about it (see pic). I thought that the calibration figured this all out, and adjusted itself accordingly?

If I lift the Z, to prevent the ripping, the extrusions are all too loose, the PLA lifts and 'blobs', and perpendicular corners get dragged out of shape, and lift up.

Lower the Z to make them tighter, and get the ripping. I can't win (but I used to)... 🙁

Re: First layer Hell - MK3 now FUBAR

Looking at that it might be a levelling issue. Print a rectangle on the left side of the be only and try adjusting the live Z to get it correct there. If you can I bet if you then printed a rectangle on the right with no changes in settings it would not stick to the bed. Also check the bed temperature on the right. It might not be heating.

Regards,
Martin

Re: First layer Hell - MK3 now FUBAR

@martin.w15

Thank you for the further advice.

I did as you said, and moved the rectangle over to the top left. Z adjusted to .750.

It's 'close, but no cigar' (see pic). On the left you can see the extrusions not quite tight enough, the bottom left of the perimeter lifted, and over to the right, well... ?

So I went again, deliberately changing nothing. Bed was wiped with 99% isopropyl alcohol, and nozzle checked.

Next attempt was an epic fail (see pic). Same Z setting, .750, and as I said no other changes at all. This was, btw, probably about the 30th attempt, not kidding. It was bad enough when I had to watch a 5 or 6 minute first layer fail 3/4 way in, for 6 or 7 times in a row, but now it's SNAFU, period... 🙁

Here's my pain. The damn thing won't even fail in the same manner twice in a row, so I have no repeatable starting point from which to debug!

That's an 80mm x 30mm rectangle, 1mm thick (if you let it complete), sliced in the latest Slic3r (1.40.0), using default settings, which have worked fine with that white PLA up until now, and I have the latest firmware (3.2.1-576). I've used different material, it's all the same. I've tweaked the temperatures up and down, to no avail.

If it was a matter of 'up the Z', or 'lower the Z', as I used to (even though that was a complete pain, as it had to be done each and every print), then I'd work with it, but it's now gone gone gone... 😥

All the tips and tricks I thought I'd picked up in four weeks of owning this thing, and which used to get me a working print, no longer do anything. As I said, it won't even fail in the same manner two times in a row. As such, what can anybody do? I've read more than a few people complaining about a similar deterioration after [n] weeks. What on Earth could it be down to?

Bed is heating, btw, but have no instrumentation to get an accurate temperature.

It's no longer fit for purpose, sadly, after three weeks of great prints. Nothing now works, no matter how I try, and if support don't give me a definitive solution, it's going back to them, but out of a cannon... 😥

Re: First layer Hell - MK3 now FUBAR

Its PLA so it should stick to a cold bed. One way of testing if its uneven heating causing your levelling problems is to try a print with the bed turned off. Try printing a rectangle anywhere on the bed with the bed temperature set to 0. If it prints or fails evenly then the heatbed heater that the problem.

Regards,
Martin

Re: First layer Hell - MK3 now FUBAR

If you repeat the same print and get different results then I wonder if your PInDA probe is faulty. Inconsistent reading from pinda might confuse the printer where is the bed. Btw, as Martin said, those waves and broken prints is because nozzle is too close to bed. Would help to confirm that pinda is healthy.

Re: First layer Hell - MK3 now FUBAR

How did you create those test squares? I realized that it's possible to generate gcode with slicer settings that will defeat any hardware adjustments I've made. If you haven't already, try the pre-generated test gcode files from the Life Adjust thread. Using those will ensure any problems aren't being compounded by slicer settings. If you get those to work (usually speed, Live Z and extrusion settings), then focus on your slicer settings. Try adjusting speeds down with the knob on the front as well.

Good luck with it.

Re: First layer Hell - MK3 now FUBAR

These things can occur if the pinda probe cuts at different temperatures.Generally the best way to carter this issue is to use manual temperature calibration.

First let us know your ambient temperature,and did you print these rectangles at some intervals or one after other.

Second do you have temperature calibration on or off.

Third try once again by putting a M860 S35 before mesh bed leveling in the startup g code.

Re: First layer Hell - MK3 now FUBAR

Thanks for the replies, everybody, I appreciate it. If only support were so quick to address my concerns (72 hours and waiting as I write)... 😥

@gaston.d3, Yes, customer service *was* going to send a new PINDA, on that basis, but that offer seems to have vanished into the ether as they prioritise getting new kits out of the door over the people whose money they now have. Sad, but true.

In some ways I hope it is the PINDA, because then I'd have a cause, but have no idea how to prove that irrefutably...

@bobstro, I use Fusion 360 for my modelling, so that was a simple rectangle, extruded 1mm, exported as a .stl file, loaded into Slic3r, then selecting the default Prusa PLA profile to export the gcode. That profile has been fine for a range of materials, with hardly a tweak needed.

I was physically moving the SD card from computer to printer, but then put Octoprint on a Raspberry Pi, which has advantages and disadvantages, the main downside being cancelling a print being a PITA from Octoprint.

Results were the same, even though Octoprint appears to send some of its 'own' gcode. My understanding of gcode is poor at the moment, but it appears it will have to improve...

@sorav.g Thanks. We seem to keep coming back to the PINDA as a potential problem. Support suggested manual calibration, and I looked at an article, but found it ambiguous, i.e. it gives some commands to use, which I can send from the terminal in Octoprint, but then it's not made clear whether to replace the entire block of gcode in the Slic3r settings with the example code, or where to insert it if it's not to be replaced whole. The Slic3r gcode sends a lot more commands than the manual calibration starting example. I shall now go back, RTFM, and try to understand it properly.

Temperature calibration was off, is now on. I'm writing this before today's 'session' - will see if that makes a difference.

Ambient temperature varies around 23- 27C in the room where the printer is, according to when we have the heating on or the windows open. A potential thing to look at? Would it make that much difference?

Rectangles were printed one after the other.

I will insert the M860 S35 command today, as I try and resolve these things, and while I'm waiting for Prusa to finally get around to answering a customer...

Thanks again for the pointers, everybody. I shall be more methodical when trying these tips, so I can narrow it down to one thing or another, and report back.

Re: First layer Hell - MK3 now FUBAR

https://github.com/prusa3d/Prusa-Firmware/wiki/Manual-temperature-calibration&hl=en-I N"> https://googleweblight.com/i?u=https://github.com/prusa3d/Prusa-Firmware/wiki/Manual-temperature-calibration&hl=en-IN

I hope it will help you.

Re: First layer Hell - MK3 now FUBAR

https://googleweblight.com/i?u=https :// ... n&hl=en-IN

I hope it will help you.

Many thanks Sorav!

Re: First layer Hell - MK3 now FUBAR

Update:

Prusa Research have indicated that the pattern may be caused by a faulty RAMBo board, so they're sending a new one, a replacement PINDA (just in case it's that), and a replacement steel sheet (which is fantastic of them), so after my moaning about them, they have indeed made me look foolish with an act of totally excellent customer support.

I shall report back, for any interested parties, when the parts arrive, and hereby publicly apologise to Prusa Research for any negative things I may have said about them, which were borne out of frustration, and which they have proved unfounded with an unexpected response which was above and beyond anything I expected.

G

Re: First layer Hell - MK3 now FUBAR

Update:

Prusa Research have indicated that the pattern may be caused by a faulty RAMBo board, so they're sending a new one, a replacement PINDA (just in case it's that), and a replacement steel sheet (which is fantastic of them), so after my moaning about them, they have indeed made me look foolish with an act of totally excellent customer support.

I shall report back, for any interested parties, when the parts arrive, and hereby publicly apologise to Prusa Research for any negative things I may have said about them, which were borne out of frustration, and which they have proved unfounded with an unexpected response which was above and beyond anything I expected.

G

That's good of them and I'm glad you have some things to try.

One more idea I want to throw out there: I've sometimes seen that tearing pattern when you're printing a little too fast. The plastic is sort of gooey as it extrudes, and if the print head is moving too fast it can pull and tear the thread before it cools.

As an experiment, try slowing your print speed way down (maybe by half) and see if that helps. If it works, you can increase the speed in increments to find the right balance between quality and speed.

Re: First layer Hell - MK3 now FUBAR

@peter.122, you're right.

When the problems first cropped up, I started playing with the 'tune' settings on the front panel. You are correct, in that slowing down the first layer *did* make a big difference.

80% saw an improvement, 70% even better. At one stage, I had the nozzle temp up to 225 (for the generic PLA I was using, not Prusa PLA), bed temp down to 55 (after somebody said the bed was too hot for another poster's picture), fan at 50, and speed at 70%.

This got me a good first layer, but only after several tries, but I could live with it. I adjusted the Slic3r settings accordingly, and saw a marked improvement. In the end, everything deteriorated to the point where nothing worked, and I ended up posting on here.

The 'wave' pattern was suspicious to me when it appeared from nowhere, looking like some kind of 'oscillation', sourced from the electronics?

I'm glad the company agree. The filament sensor has never worked from the beginning, even though they've sent three. The wiring was checked, and the headers and pins, so I thought the RAMBo board (einsy? I get confused...) must have had a dodgy chip/header/whatever.

This wasn't a deal breaker, as the filament sensor was a nice thing to have, but I could work without one. Perhaps that was indicative of something amiss on the board?

Fingers crossed that the replacement parts do the trick. I shall install them all *very* carefully, but then I took great care building the kit in the first place, and was pleasantly surprised when (apart from the filament sensor error) it all worked with no adjustments needed on the belts/rods/axes.

If it does turn out to be the board, I have no idea how it would 'fade' after a month of sitting in the same place, in a comfortable room, but mine is not to reason why...

I can certainly live with a really slow first layer, no problems at all, as the rest is always very good / excellent, 99% of the time.

I feel guilty about moaning at tech support / customer service, and got a little self-centred about it all, which was uncool. It was all borne out of frustration that this excellent machine was 'fading away' from me, and they must deal with *lots* of people every day, so I need to be a little more patient.

Thanks again for the advice. I'll gladly accept a 1% speed first layer if it works... 😉

Re: First layer Hell - MK3 now FUBAR

@giulio

As your parts are on their way.
In the meantime,I suggest you to please do manual calibration and first let me know you results after putting a M860 S35 command before bed leveling G28 .

I am pretty sure it's pinda temperature effect.

Re: First layer Hell - MK3 now FUBAR

@sorav.g

Thank you for the tip.

I've been so downhearted about the experience, I put the MK3 in the spare room until the parts arrive, as I'd spent far too many hours trying everything suggested to me.

I *did* try the M860 S35 command, and I initially thought there was a marked improvement, but then part of the now improved first layer lifted up, the nozzle caught on it, and ruined it all over... 😕

The parts coming include a replacement PINDA so, although I totally agree with you about trying the current one with the gcode 'wait' command (which, to repeat myself, DID improve things), I'm going to replace bits one by one to try and narrow down the exact issue, when they arrive.

Be sure that I will absolutely try the manual calibration again, if the replacements do not solve the problem.

Thanks again for the input !

G