One of my fixes for knobs with cracked hubs like you're describing is to glue as you've done, then 2-4 lines of CA on the outside along the long axis of the hub, then slip a length of heat-shrink over it all and hit it with the heat gun. The CA on the outside dries almost instantly, but watch out for CA creeping inside the hub. When it's all dry ( you can test with a Q-Tip swab to be sure ), trim the excess HS tubing off the end and good for another couple decades unless some college kid gets a-hold of it.
I was thinking heat shrink tubing, too. Good idea, the CA reinforcement. I shall keep that in mind.
Yup, gluing the hub to the heat-shrink really improves the rigidity of the repair; helps the knob not feel wobbly underhand.
TinkerDwagon Minute: Patching CablesI've used a similar process to repair cables on lawnmowers that have been damaged by careless folding and cracked out to uselessness; often these are unobtanium or if they are available they cost more than the mower is worth, so it's either fix the one you have or cobble a generic one in to sortof work. Okay, okay... I'll admit I've done the same thing on bicycle cables too,
just because I couldn't be arsed to go out to three different stores to find the right one.
Trim off the excess peeled up plastic sheathing, then hand-straighten the damaged area so the cable moves properly if you hold it straight. Clean with alcohol, then coat the entire outside of the cable with hot glue approx 2-3mm thick, covering any bare metal spiral and 50mm-ish down over good sheathing either side of the damaged area. Just make sure you get good coverage and as even layering as possible without going crazy; it doesn't have to be pretty.
Next, cut yourself a piece of heat-shrink with the right ID that that it will easily go over the entire mass but still will shrink down to the cable diameter (finding this balance is key for a good repair), and about 20-25mm longer than the hot-glued area. Uninstall one end of the cable from the mower, put the heat-shrink in place, and then reinstall the end of the cable. Now commit your heat-gun abuse; the hot-glue under the tubing will coalesce into a little bullet-shaped "lump in the cable". While it's all hardening, operate the cable and adjust alignment by hand for free movement, then hold it in place until it's done setting.
I've used this repair on my lawnmower here in the middle of the Tejas summer and it still holds, so pretty sure it'll hold for most applications, unless the damaged portion is right against a hot area of the engine.
Happy Tinkering!mnem
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