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+-- Thread: Q: Keyed Sprocket to non-keyed (/showthread.php?tid=7374807)
Q: Keyed Sprocket to non-keyed - pconroy - 01-17-2024
After years, I'm replacing the dumb Timing Belt Blade Raise mechanism in the Jet table saw. The timing belt and two gears are out. Prepping to be replaced with sprockets and a chain. The second gear was keyed. That's it on the left. The new replacement sprocket is not.
I have no metal working tools. Can I try knocking the key off the shaft, installing the sprocket and screwing the set screw into the old key slot? I'm not sure I've got another choice for today.
The saw isn't a production saw - I cut stuff maybe once a month, if that. I'm wondering if I can try my non-keyed sprocket and just see if it works. Maybe down the line, spend the $15 for a keyed one if this one slips.
Or is this an immediate path to failure?
thanks
RE: Q: Keyed Sprocket to non-keyed - kencombs - 01-17-2024
I wouldn't use the keyway as a place to put the set screw. Might deform the keyway and make if difficult to go back if needed. But, I'd slip the pulley on without the setscrew and drill a dimple into the shaft opposite the keyway. Just a little dimple and use a pointed setscrew.
You can cut a keyway by hand with a hacksaw and files, accurate enough for that use. But it's a lot of work and IMHO not worth it.
RE: Q: Keyed Sprocket to non-keyed - pconroy - 01-17-2024
thanks ken, I should have enuff room to get a file up there and see if I can file a flat spot on the spline for the set screw. If I can find room for a drill, I'll try to make the dimple first.
I've never removed a key, I assume some gentle taps with a punch will knock it out?
RE: Q: Keyed Sprocket to non-keyed - lift mechanic - 01-17-2024
How is the fit to the shaft? If it is a snug fit, you could use Loctite RC/640 Retaining compound. Or use Loctite RC/680 high strength retaining compound. Both have worked well for machinery that I worked on. Still use the set screw, but not in the keyway. You could do as Kencombs said and slightly drill the shaft where the set screw will hit the shaft.
RE: Q: Keyed Sprocket to non-keyed - pconroy - 01-17-2024
Right now, I gave the key a little tappy tap tap and it didn't move.
Ta'marraw, I'm upping the tap level.
RE: Q: Keyed Sprocket to non-keyed - Stwood_ - 01-18-2024
Grab some dykes,side cutters and grab the keyway and push down towards the shaft and pull it out.
Center punch the shaft before trying to drill an indention on a round shaft, which is almost impossible unless the shaft is set up on a drill press table and vise.
RE: Q: Keyed Sprocket to non-keyed - pconroy - 01-20-2024
Got it installed. It was a little of shoe-horning, cussing - but it's working well. So far.
Thanks all