***UPDATED***
Added a whole mess of photos to help with assembly
updated the spring for a little more oomph
The goal was to only use stuff I already had.
BOM:
The lever is some 10mm carbon tube i had from and abandoned project cut to 200mm. A 10mm linear rail should also work but may be too heavy.
2x 200mm 2020 for the frame
PLA for all the printed parts, except the grippies, which are TPU
A couple m5 screws for the feat, though I'm not sure its needed and one for the “snug arm”
A bunch of shorty m3 screws and heat sets
M3 and m5 hammer head nuts
1 m5 nut
200mm mgn7 linear rail
2x 608 bearings
1x 3x2mm nylon space - could probably print this - goes between tie rod and iron mount
M2 bolts to attach iron mount to rail
Zip ties
Soldering iron like this one
Some sort of corner bracing between 2020's
Short tapping screws for linear rail to backer- m2 bolts may work but I haven't tried - may have to make holes bigger.
Super glue for feet grippies. Use sparingly as it squeezes out and glues your fingers to the print. Ask me how I know
I have included the step file so can be remixed. I would suggest using a brim with the spring printed on its side.
The arm mount is intended to be adjustable up and down as well as the tie rod mount on the arm. This changes throw and leverage as needed.
608 bearings are a press fit. I cracked the mount in the picture so the clearance has been increased slightly, but the crack also doesn't seem to affect it.
The smaller end of the axle bulged a bit so also clearanced larger, but didn't want to go too much so may nee so sand a bit.
Included kind of an exploded view to help with assembly. Doesn't show bots, nuts, or hammerhead nuts, but I think it should be easy to figure out.
Cable clips are a tight fit. I spread them a hair with a flathead before installing
Edit: this would definitely benefit from a heavier base. Printing the feet with 0 infill and filling with sand or just mounting to the bench or a big piece of wood are my thoughts. Would love some feedback.
UPDATE 4/6
Added an mgn9c compatible soldering iron clamp arm thingy. I don't have that rail so it is un tested.
The author marked this model as their own original creation.