I tried to recreate historical rolling nut trigger mechanism for crossbows in a way that will make it reasonably accurate, but also printable and good for toy crossbows.
Use nails glued in, or metal screws, for axes and stop-pin limiting rotation. Forces shouldn't be too big but I don't want to trust plastic with that. I know different diameters are not optimal from the bill of materials perspective, but that should be like ten cents in any big hardware store that sells them by weight, so I figured I don't care at this stage.
Tolerances are intentionally very loose, but plastic washers are cheap, and hand cut cardboard ones should do just fine if needed. Use Teflon washers if you are feeling fancy. Scratching layer lines would be worse and I absolutely do not want this to require any kind of sanding, or fancy printing rules like only this orientation and layer height. Nope, this one is supposed to be stupidly easy to use by lazy people.
This is a work in progress. I'll upload progress after test prints, but at this iteration I'm convinced it should work using ABS-like resin.
Note, I post it under CC Attribution Non-Commercial Share-alike license, and I understand my wishes are not legally binding, but this thing is meant to be used only for purposes of education, and toy building. Other uses, especially for real crossbows, would be against my will. Please don't do it, even if it's legal.
I used tinkercad.com and photos of historical crossbows for references. Hope you'll find this useful.
Category: EngineeringThe author marked this model as their own original creation. Imported from Thingiverse.