I am so angry. This printer has such a high fail rate.  

RE: I am so angry. This printer has such a high fail rate.

Posted by: @tim-m30

Of course, you can continue to believe the printer is going rogue and plunging the nozzle into the part; but seriously, it can't happen unless something in your gcode is telling it to.

Or alternatively, the printer electronics are for some mysterious and supernatural reason playing with your psyche.  Yours would be the first printer to do this.

 

As for you part not being warped? You showed us a photo: that photo shows a very clear warp that I circled (the shadows aren't lying). Also, that warp is exactly where the nozzle was banging on the part (melted areas) before it finally broke loose and was sucked up into the nozzle by the surface tension of melted plastic.

I love internet know-it-alls.  You basically just told me that I'm a liar, when I watched it happen.  OK, whatever. Points for you.

I learned about the warping issue early, because I could hear the print nozzle or the PRINDA clicking on the curled up sections.  There is absolutely no way to completely eliminate some amount of warping on parts like this; the next best alternative is to print them in a different orientation - which I do not, because I am using the finished aesthetic, as is.  The point that I made - ignore me not - is that it WAS NOT this area that failed the part.  There are thin sections facing forward and back, and I mitigated that influence, best I could.

You don't need to reply any further.  Thank you for your help this far.

RE: I am so angry. This printer has such a high fail rate.

Good luck with your new printer. I’m sure everyone who responded here would appreciate a report once you had a chance to test it, to see if the problem is in fact caused by the printer or the model. 

Personally I’ve seen something like what you described maybe once or twice but it didn’t happen again when I printed the part again so I shrugged and wrote it off as a fluke. 

RE: I am so angry. This printer has such a high fail rate.

Posted by: @fuchsr

Good luck with your new printer. I’m sure everyone who responded here would appreciate a report once you had a chance to test it, to see if the problem is in fact caused by the printer or the model. 

Personally I’ve seen something like what you described maybe once or twice but it didn’t happen again when I printed the part again so I shrugged and wrote it off as a fluke. 

Will do.  

My last ditch effort, is to slow the speed down to well under 50% for the final 30% of the print.  That's a half-baked solution, and shouldn't be necessary -  but it has worked on a couple of occasions (but it's far from perfect)

I wish I could relegate this problem to fluke status, but I'm looking at a pile of 5 parts that are headed to the shredder.  All of them have 20+ hours on them.

RE: I am so angry. This printer has such a high fail rate.

Posted by: @mhanson

I'll contact them, but I'm gifting this printer to my son.  To be perfectly honest, it's too much of a tinkerer's toy.  I want a serious piece of equipment, and I don't have time to fool with these types of issues, or to open source my product support.

Well good for your son then! You did pay for Prusa support, so I'd at least give them a go. No matter what your level of disdain for the product is at the moment, I think you can agree that it is possible for many Prusa printers to successfully print without plunging the nozzle into the part mid-print. I would be curious to see what results you get with a simple cube or cylinder that exceeds your 60mm trigger level sliced with another slicer or the result of printing the Prusa-supplied gcode. You have nothing to lose by trying.

In any case, good luck. Happy to suggest more ideas if you're game.

RE: I am so angry. This printer has such a high fail rate.

Just for clarity, the "open source" support is here on the user-user forums. You're stuck with a bunch of us helping each other out on a volunteer basis. You are also entitled to direct manufacturer support from Prusa. The best means of contacting them is via chat after logging into the online store. They receive high marks and are very good at working through problems. With any vendor, you presumably would want to at least give their support a chance before condemning the product outright. Prusa does run a farm of over 500 of these printers producing one of the best-selling 3D printers in the world, so they've got some chops. I hope you can get past your immediate frustration and get the Mk3 working as you expected.

RE: I am so angry. This printer has such a high fail rate.

Since you are gifting the Mk3 to your son, and aren't satisfied with home user class FDM printers, might I suggest this commercial printer? 

https://formlabs.com/3d-printers/form-3l/

Or if fluid printing isn't acceptable, here's a moderately priced FDM:

https://www.raise3d.com/products/pro2-plus-3d-printer/

RE: I am so angry. This printer has such a high fail rate.

Posted by: @tim-m30

Since you are gifting the Mk3 to your son, and aren't satisfied with home user class FDM printers, might I suggest this commercial printer? 

https://formlabs.com/3d-printers/form-3l/

Or if fluid printing isn't acceptable, here's a moderately priced FDM:

https://www.raise3d.com/products/pro2-plus-3d-printer/

 Will check out the FormLab.

I don't do ABS, but the few times that I've needed to, I have a colleague who prints ABS for me with FDM.  So I probably won't do that one.

RE: I am so angry. This printer has such a high fail rate.

Posted by: @mhanson

[...] My last ditch effort, is to slow the speed down to well under 50% for the final 30% of the print.  That's a half-baked solution, and shouldn't be necessary -  but it has worked on a couple of occasions (but it's far from perfect)

Am I correct in understanding that prints do succeed if you slow the speed down? Surely if the nozzle is being driven into the print, reducing speed would not eliminate that problem. The nozzle would just be moved more slowly. It sounds like reducing speed is reducing curling.

In your circumstance, I'd suspect that the reduced speed is giving the freshly extruded filament a bit more time to both adhere to underlying extrusions (critical for overhangs) and cool before the next pass, reducing curling which can snag the nozzle or fan shroud.

I wish I could relegate this problem to fluke status, but I'm looking at a pile of 5 parts that are headed to the shredder.  All of them have 20+ hours on them.

I'd suggest creating a smaller test print, or slicing up your large print for a few test runs before going all-in on 20 hour tests. Can you cut the STL in the slicer to isolate the problem area? Or recreate it in a simpler part?

Re-reading your original post, it sounds as if you are using supports to reduce curling on thin overhangs. That's not really their intended use, though it can be a side-effect. In order for supports to be removable, a gap between the support and supported part is used. Curling can occur above this and the support does not "tack down" the part.

RE: I am so angry. This printer has such a high fail rate.

Does the same happen with the same model but using another filament? This jetblack is nice color but i do not likesometimes  its behave.

RE: I am so angry. This printer has such a high fail rate.

I also experienced the nozzle 'slamming' into the print a few times and dragging over it. It was unable to dislodge the part from the bed because I printed PETG directly onto (a well cleaned) PEI sheet. So the noise was audible through the whole house. Sounded like an air rifle going off. It did that a few times before I realized what went on. Once I watched it closely i could see it happen real time.

End result was a damaged upper X rod and 2 shot bearings on the same rod. They gauged the rod well, so you could see and hear the damage.

In the end, Prusa RMA'd the damaged rod and bearings and I resliced the file and it never occurred again. Why did it happen? I have no idea. I chalked it up to the slicer producing crappy gcode. Your issue should be addressed to Prusa Support. They should be able to help you out, their tech support is really good.