MINDA Z offset issue  

RE: MINDA Z offset issue

Update: Prusa had my Mini for just over 2 weeks. All they did was lubricate the bearings, tighten the belts, and flash the firmware with version 4.2.0. I performed a first layer calibration when I got it back, making sure to leave it at the value they set it to and I didn't have to adjust it. I performed a second first layer calibration and it was perfect. It appears the z-offset problem is resolved but I will definitely keep an eye on it. The frustrating thing is that they didn't find a clear cause. The only thing I can think of was that firmware version 4.2.0 fixed it. I shipped the printer back to them on 8/3/2020 and version 4.2.0 came out on 8/5/2020. 

What's more frustrating is that my smooth PEI sheet is badly scarred from this problem and they won't replace because they said it still has one usable side and I could have prevented it if I was watching the first layer. Obviously, I was watching the first layer but I shouldn't have to adjust the z-offset before each print and it's unclear if the nozzle is too close until it literally hits the print bed during the initial wipe. They also found a connector damaged on the buddy board which they claim happened due to my inadequate packaging. It's not easy to ship a printer, fully assembled as per their request. It's a connecter that is not yet used and isn't destroyed. Besides, it will cost me over $100 to replace the buddy board. 

Basically, I received this printer 9 weeks ago and am now able to use it as intended, hopefully. On top of that, I have a damaged smooth PEI coated sheet and a connector on the buddy board for some future hardware that I am responsible for replacing despite them being a consequence of a flaw in their machine. I thought they would at least replace the smooth PEI coated sheet.

I just filled out the printer review that was sent to my email and I made sure to give them my honest feedback. Oh I almost forgot, the back right foam foot that gets installed on the back right corner of the extruded steel frame was deformed when I got the printer back. As soon as I placed in on the table the printer tipped toward the unsupported corner of the electronics box. A design flaw that is easily remedied with a 3 mm thick piece of foam. So made sure to give them that feedback as well.

RE: MINDA Z offset issue

Prusa is generally excellent with support, with the exception of the removable print surfaces. I had a textured sheet that (after waiting 14 months for it to arrive) would not adhere with any filament. On contact, support immediately blurted out that the sheets are a consumable. I suspect this is an internal policy. While I understand it to some extent (lots of people screw up their sheets through carelessness) it was disappointing. The good news is that sheets are relatively inexpensive and you do need to plan on eventual replacement. Look into 3rd party options now that they're becoming available. I like BuildTak's PEI sheets myself.

RE: MINDA Z offset issue

@bobstro

I know it's not that expensive and that I could have prevented it if I were more vigilant. I still think this printer is amazing but I obviously have a bad taste in my mouth over this experience. I think it produces beautiful prints and I even think it performs better than my Mk3S. But, my Mk3S has given me little to no trouble in the almost 2 years I've owned it. If I didn't already own a Prusa and I were a brand new customer, especially to 3D printing in general, then this would be an even more disheartening experience. I have faith that Prusa will polish this printer to a higher standard and I want to help them do it. I actually enjoyed troubleshooting because it forced me to learn a lot about this printer in short amount of time. I'm a tinkerer at heart so I enjoy learning the ins and outs of tech. It's most likely why I was drawn to 3D printing in the first place. 

RE: MINDA Z offset issue

I'm having issues with this here too. firmware is 4.2.1 - seems that MBL doesn't compensate like you said, and i'm constantly running first layer calibrations between prints, sometimes multiple times. it's infuriating.

so should i downgrade to 4.2.0 or contact support or... uh... whine and wait for Prusa to offer a real fix?

RE: MINDA Z offset issue

@arklan-uthoslin

Don't downgrade to 4.2.0, there is common issue with BSOD which gets patched in 4.2.1. But maybe possibly try factory reset? It helped few people with their weird issues, though probably not with Z offset.

RE: MINDA Z offset issue

@crawlerin

well, thanks for that at least. 

RE: MINDA Z offset issue

@crawlerin

I'm on 4.2.0 and it's more consistent print-to-print, I'm a bit paranoid of upgrading since it's actually working a bit better now.

RE: MINDA Z offset issue

I have the same issue and its very frustrating. My Ender3 with a BLTouch never has this issue, very frustrating considering the price I paid for a mini printer. 

RE: MINDA Z offset issue

@sometimesforever

Welcome to the club, I just had an offset of .160mm in between prints. 

Would've lost the print if it weren't for my quick intervention.

And yes, I have the probe at 2mm high over the center of the bed and let the temperature stabilize by preheating for awhile.