Dr Joe's Unchain the Cracken No. 25

grabcad

A chain cracking mechanism that has it all. Cracks #25 Chain (standard and heavy).No added tools required. Printed on Fuse1+ in Nylon11 CFIncludes a lot of metal bits inside (core pins, shaft keys, bearings, 10:1 Versaplanetary gearset, screws, dowels). Not cheap but the performance is amazing (in my opinion).Geneva mechanism counts turns but also provides "hard stop" to keep you from breaking the mechanism by cranking the wrong way (after a 10:1 gearset, cranking the wrong way against a "hard stop" seems a lot like pushing pins out of #25H chain -- only the crack you'll hear is the plastic housing giving way). Has an (almost) fool proof set of doors that make it difficult to have out of position chain before you Unchain the Cracken. Print in place rotating knob on the crank. Feels so nice when you crank. Presses 2 pins out at once so as long as you position a chain such that the pins are over the plates (not the links) you don't make chain sections with dangling plates (so annoying to be making a chain section and you have to finish the work of some lazy person before you that left the plates just dangling away).Unchain the Cracken No. 25 BOM https://docs.google.com/spreadsheets/d/1Il2cCkk7ygPh2SExZtbnfJfYzDaypg4br8M6J0n4pFY/edit#gid=0