Z-axis steppers and bed alignment problems
I've actually solved this, but I think its still a useful question which I don't think is easy to answer with existing questions.
As soon as I'd built my ANET-A8 (Prusa i3 DIY kit), I found I was having problems with the extruder crashing into the bed. Although I thought I'd adjusted the bed leveling OK, the calibration seemed to keep getting messed up.
I tracked this down to two factors. First, I was winding the extruder head up some distance before loading the filament and starting a print. Second, at roughly half-way up the axis, the right-hand thread seemed to be getting stuck (more often when moving up than down).
What wasn't clear (and not mentioned in the building instructions) was what might cause this problem.
@SeanHoulihane There's no such thing as a "clone". The Prusa design is open-source and in my opinion, "Prusa" refers to any number of designs.
So after reading the instructions more carefully, ANET do cover this in their operating instructions under troubleshooting. On closer inspection, I realised that the brass nut following the right hand thread seemed to be out of alignment with the stepper at the bottom. Fiddling with the flexible coupling helped a bit, but what I needed to do was place the assembly at the tight point, slacken the 3 bolts marked
SHCSin the diagram, then tighten them again. I was expecting I might need to open out the holes, or re-make the white (factory printed) part, but this wasn't necessary.
ha! so there is caret nut :) it's good to hear you've solved it (btw: my suspicion about 1. assembling according to instruction was priviledged) ;) and 2. that there is a problem was priviledged too)
I don't think `caret nut` is a real word. It is probably a mistranslation.
@darthpixel - I would wager that `caret` actually means `carriage`, as in _the x-axis carriage_. Mostly because of the phrase in Tom's answer, _which can eventually hang caret_, which probably should be _which can eventually hang [the x-axis] carriage_
where did you find this under troubleshooting, I think Im having the same issue. Can't find what you are refereing to.