Ongoing problems printing large surface areas.  

RE: Ongoing problems printing large surface areas.

Would it be possible to upload a project file containing the model and the settings you're trying? Sometimes non-obvious things are much easier to spot that way. Just save your slicer setup out as a project file (3MF format) and zip it to upload it here. FWIW, I have done many near-full bed prints of very similar style using PLA on the Mk3, so the printer is definitely capable of handling this. The tool trays in this pic were all done recently, and I've done larger drawer inserts for my desk.

RE: Ongoing problems printing large surface areas.

Sure thing, here's a zip file that contains both the project file and the STL itself.  For months I printed large objects without any issues.  this started a couple of months ago and now happens quite frequently.  

printfail

RE: Ongoing problems printing large surface areas.

filament absorbing moisture i expect - time to dry it out in the oven or dry box

RE: Ongoing problems printing large surface areas.

@david-a66

I had the issue with a brand new, just opened roll of filament.  

RE: Ongoing problems printing large surface areas.

@david-a66

and I don't really see why wet filament would cause run away problems like that and only on large surface area prints. Stringing issues sure.  And like I said I can print other stuff just fine. The print job I'm currently running uses more of the print bed but it's 3 copies of a medium sized object instead of 1 large object.

RE: Ongoing problems printing large surface areas.

The images look like the very typical crash situation where something is binding and the printer is losing steps.   

There isn't anything else that will really explain the offsets during a print.  Friction is key here: so knowing what the numbers are for the "belt tension" will be especially helpful.  Also, what the power supply voltages are reading (also in the LCD menus).

Post up this info and then ideas may flow.

RE: Ongoing problems printing large surface areas.

@tim-m30

I’ll get that info for you later tonight or tomorrow morning.

RE: Ongoing problems printing large surface areas.

@tim-m30

Belt values.  X:269/Y:290

Power: 24.1/24.1v

RE: Ongoing problems printing large surface areas.

The tension numbers don't have any surprises. X is a bit tight, but not down where I'd expect issues.  But you might power off and slide X and Y back and forth to feel for any sticky or rough spots.   If you do feel ANY stickyness, even one spot, add a drop or two of machine oil on the rods and work it into the bearings until they go away.

Second questions: did you grease the bearings before install?  And, is the printer reporting any crashes? 

Another cause of crashes is cables snagging. Both the extruder cable on the Einsy case and stray cables not dressed below the frame.  Both axes crashes, as your are, is often dry bearings, cables snagging, or less often power issues. 

ps: the larger parts allow the printer to reach the full speed it is capable of; whereas small parts the printer never has the chance to accelerate.

RE: Ongoing problems printing large surface areas.

Did you solve this problem? I have been having exactly the same issue.

I'm not sure if it started at the same time but I am also finding that I usually have to reset the printer between successful prints because as I navigate the SD card it goes nuts and starts making strange noises like it's going to tear itself apart.

I've become suspicious of the recent firmware updates, and am considering an experimental downgrade to 3.7.2, as I know for sure I never saw this before installing that.

RE: Ongoing problems printing large surface areas.

Correction, contemplating downgrade to pre-3.7.2.

I may try 3.7.2 first, but I think I installed 3.8.0 hoping it would fix this.

RE: Ongoing problems printing large surface areas.

I went ahead and ran that experiment; downgraded to 3.7.1, still happens. It does seem to fail in similar spots, which at one point led me to suspect the slicer, but it's not the exact same spot, so maybe some kind of cumulative effect.

When I am present for this to happen, I usually see everything halt for a second, and then the display briefly says "Heating...", even though temps are fine, and then it continues. It seems to continue as if it had kept moving during the pause, causing "runaway" like in the photos posted by kit-s. Often it seems to kind of recover, but these prints eventually turn into a huge mess, so now once I see this, I cancel right away.

In general I've taken to slicing large objects into smaller pieces and gluing them together but that's really getting tiresome.

RE: Ongoing problems printing large surface areas.

Posted by: @kit-s

[...] Basically whenever I have an object with a large surface area everything starts to go wonky after the first layer or 2.  Smaller prints still work fine but anything using around 50% or more of the build area tends to suffer from this problem. It's really getting frustrating as it means about 20% of the things I need to print I simply can't.

@kit-s when you first posted this, I hadn't seen this problem. I since tried a similar print with similar results. Everything is fine until layer 2, then it goes bonkers. There's a GitHub issue open on this problem. For now, try disabling your filament sensor. There will hopefully be a firmware update fixing this in the future. I've been traveling, so have been unable to try disabling the filament sensor.

RE: Ongoing problems printing large surface areas.

Wow. Great. 

This is definitely the problem I've wasted a lot of time and filament on these past few months.

I'm a bit worried because it seems I was right to suspect the firmware, but I *did* just a few hours ago try downgrading to 3.7.2 and it still failed, but I'm going to upgrade back to 3.8.0 immediately and start the same print for the fifth time with the filament sensor disabled, and we'll see how it goes.

RE: Ongoing problems printing large surface areas.

This seems to be working. Just finished a pristine layer 2 on a 160mm circle I've been struggling to print for a while now.

Between this "fix" and 7x7 bed leveling, it may be the cleanest layer 2 I've seen in months.

Thanks for posting, bobstro!

RE: Ongoing problems printing large surface areas.

Posted by: @sam-n4

This seems to be working. Just finished a pristine layer 2 on a 160mm circle I've been struggling to print for a while now.

Between this "fix" and 7x7 bed leveling, it may be the cleanest layer 2 I've seen in months.

Thanks for posting, bobstro!

Hoping to finally get back home and try my prints again. Thanks for the update, glad it worked.