Solidoodle 2 M3 Z-Axis Nut Holder by brucesdad13

Last crawled date: 2 years, 12 months ago

M3 nut holder for Solidoodle M3 Z-axis rod hack. See http://www.soliforum.com/post/127928/#p127928 for more background on the mod. It didn't appear that anyone had yet posted a Thing for the 3mm nut hugger so I cooked this up based on http://www.thingiverse.com/thing:159671 (amazing thank you!). I projected the geometry and adapted for smaller m3 nut vs 5/16". I only printed the one part. My tolerances were a little tight so I heated an m3 nut with a lighter and pressed it in. I insert two nuts into the hex with hammer or lighter and then cap on either side with a retainer part.
BoM:
18-8 Stainless Steel Fully Threaded Rod, Meets DIN 975, M3-0.5 Thread Size, 1 m Length, Right Hand Threads for $12 (have plenty of rod leftover for next project!
3mmx5mm 16mm Dia 20mm Length Motor Shaft Beam Coupler Coupling Connect for $6.84
2 x M3 nut to insert into hugger
small amount of super glue... perhaps ABS slurry would work
4 x screw and nut to mount ... I used 6-32 screws since I'm drowning in non-metric hardware ;)
The results are superb accuracy. The rod is very bendy and flexible and that's totally fine. Slow down the Z motor and update the steps. According to Prusa calculator and forum the resulting steps 6400 and 3mm speed.
GCode post-mod:
M92 Z6400 # update steps
M203 Z3 # slow down Z
M500 # save to EEPROM
References:
http://www.soliforum.com/topic/2154/fixing-banding-zwobble-with-fine-threaded-zrod/
http://prusaprinters.org/calculator/
http://www.metrication.com/engineering/threads.html (M3 pitch 0.5 for Prusa calculator above)
Changelog:
2016-12-11 - My M3 nuts worked their way out so I've added another part that will hold them in place. One is to be placed above and one below the part with the hex opening. Drill holes to size.. I drilled mine slightly wider for 6-32 screws.