A one hour shop project

[Don42]

Photos, but not another video of chips being made. This can be read in two minutes.

The scabbard for my HF 10" cordless chain saw kept falling off, leaving the sharp chain exposed to get damaged, do damage or both. So I devised the FSRK: Foremanian Scabbard Retention Kludge, a one-hour project.


I have a coil of 3/16" dia bungee cord (from AxMan surplus) on hand as "handy stuff". The part that may be interesting to some is the method of termination which is far less clunky than that found on commercially available bungees.

I made a hook for one end out of 1/8" steel welding rod for TIG or gas. It grabs the handle of the chain saw. On the other end is a smaller part made of 1/16" stainless TIG rod that could be secured to the scabbard with wire ties.

I made some little ferrules by slicing off short bits of 3/8" OD soft copper tubing and deburring them. I mashed them in a vise to sort of an oval shape to accept the folded over bungee cord. Then I crimped them in this tool from Harbor Freight:


It's a hydraulic crimper, meant for crimping electrical terminals. It comes in a plastic case with die sets for wire sizes 0,2,4,6,7,8,10 and 14. Regular price is $69 but it was a lot less than that on sale some time ago and may be again. Being hydraulic, it doesn't take no for an answer. I used the #0 die set for this job. As can be seen, the cavity in the die is hexagonal. When a round or oval ferrule is squashed in it, the ferrule becomes hexagonal because the die cavities are hexagonal and hydraulic force quietly requires compliance.

That reduces internal area because a hexagon of given distance between corners has less enclosed area than a circle of that diameter. The result, in engineering terminology, is that it squeezes the crap out of whatever is inside that area. The circumferential ferrule material that is thus made surplus is mashed flat on both sides to form ears on the crimp.