Mini in a box for two years... Here's what I had to do to get it working again!

Hi All!

About two years ago, I moved and packed up my mini. It stayed in the box until last weekend, when I got the itch to build again!

Unfortunately, getting it up and running was not as straighforward as I would have liked.

I ran into a few problems that I solved (after a lot of frustration) I figured I’d post here about them in case someone else runs into them.

The first was that my firmware was so old that it wasn’t reporting to be the correct printer, which would disconnect it from CURA. To solve this, I had to go into the settings and allow the unsafe option. This was pretty scary, and the tooltip didn’t call out that this might be required if your printer is sifnificantly out of date.

The second was that the printer wouldn’t auto level. It would go down to the washer quickly then back up an wipe. All the info I found said my tip was dirty. I did a ton to clean it. I checked resistances, trigger states etc. Everything checked out. Then I ran it again and realized I wasn’t convinced that the tip was ever making contact with the washer. It was getting REALLY close, but never actually hitting. I confirmed this by putting something conductive where the nozzle would come down, and sure enough, it continued on to the slow approach… before missing the fast approach on the next washer.

I dug into the source code and found that there is a minimum value that it will check (-2 I think). Likely this is a new limit, since I never had this problem before. As best I can figure, my mini is actually a bit taller than spec. I manally figured out that I would hit the washer at about -2.5, below the sofrware limit. I ended up solving this by adding a G92 Z159 (set absolute Z value to 159mm) after the home (G28) and before the leveling (G29). Typically this is assumed to be 158 but my mini is too tall!

Finally, I could get past all of the bed leveling. woo. Unfortunately, I found that nothing was coming out of the extruder. I read a ton of suggestions (cleaning it, too close to bed, etc) however I was able to extrude manually, it just wouldn’t extrude while printing. In fact the extruder motor wouldn’t even move! I finally tracked this down to the fact that, in messing with settings tring to debug the previous issues, I had changed the GCODE flavor to Bits From Byes. Not sure exactly what the difference is, but using that flavor on a mini makes the nozzle move around like its printing but not move the extruder. Putting this on reprap fixed it.

Finally last night (after 3 nights of hacking), I managed to get a rocktapus printed! Excited to be up and running again!

Hope one of these solutions helps some poor soul avoid spending so long on all this!