Ever wonder how they manage those strong recoil springs in lawnmower starters?
Me neither. If spring breaks, buy new cartridge for a coupla bux rather than messing with it.
But today the windup spring in my cheap new air hose reel made a BRAPPPPP noise and then quit working. Somethin' had come unstuck. The hose reel works like a window shade -- pull to feed, release slowly to latch, and so on. It broke like a windowshade mechanism as well -- I'd heard that sound before.
Took the reel apart. There is one humongous clock spring in that sucker, makes a recoil starter look like a small clockspring by comparison. It's about 3/4" wide, fairly thick (easily .030 by eyeball measure) and there is lots of it. The drum it lives in is over 4" ID. Sure enough, the fixed end wasn't. The outer hook bend in the spring had partially straightened out which makes me suspect manufacturing defect because the much smaller right-angle tab on the inside end was fine.
Got that fixed no problem, hung the hook on it's substantial peg and commenced to try to rewind it small enough to get a closed band around it that had surrounded it before but got away. I thought for a while the band might be a radial containment so as not to stress the plastic drum -- but after fighting that unruly bad-attitude recalcitrant incorrigable sonofabitch it suddenly donged on me what that band was for. They probably wind the spring up between two discs in some kinda machine or fixture and then band it while it's wound and captive. The partially-wound band-contained spring is then a docile hockeypuck that can be easily handled during assembly.
I could wind the spring OK up to a point. Then it decided if I made it wind rotationally further when it didn't wanna it'd sproing on me axially, screw me if I couldn't take a joke. It was like a gunnysack fulla raccoons. I really didn't wanna make an axial containment jig to rewind this devil, but was seriously considering it when I discovered that if I moved the center way off to one side then it was much easer to keep the rest of it from sproinging axially. It's one of those jobs that needs 3 or 4 hands. After a couple of tries with only minor loss of skin and blood I got it wound enough and OD reduced enough that I could slip the restraining band back over the outside. Voiley, it was then tame as could be. The rest of the reassembly was uneventful and it works great now -- much better than it did originally. Sucks that airhose in like a kid eating spaghetti, THOOP!
Another home shop trick y'all probably know about: save metric screws! Whenever I scrap something like a computer, printer, scanner, etc I spend a little time cannibalizing for goodies: supermagnets out of disc drives, little DC motors, opto sensors, ball bearings if any -- and metric screws. My little stash of metric screws comes in very handy at times like today. As usual, a couple of the screws got away from me to be rediscovered another day when looking for something else. No problem, dipped into the scrounge jar, selected a couple that fit, completed reassembly with no problem and no aggrivation.
I still have a can of metric bolts from wrenchin' on cars, though I don't do that much anymore and don't miss it a bit.