HELP?: preventing collar from slipping

[blacknwhite]

Hi, this is my first post. I've collected 8 windup grammophones since I was a kid, one 78 jukebox, and over 6,000 78's. Hope someone can help me.

Any ideas on how I can prevent the collar of the speed-adjustment lever from slipping on the shaft?

This is for a circa 1945-47 grammophone. I usually don't even look at ones from this era, but this one's in showroom condition, the only one I've seen looking & sounding this good, and totally quiet motor. Gonna clean it up, enjoy test-playing it, then pass it along on the 'bay, to help make this hobby pay for itself.





The speed adjustment lever had obviously been slipping when I got it: The lever was all the way on "Slow", but it was running about 90 RPM. I re-calibrated, but I don't know how to prevent it from slipping again. The tensioning spring that provides friction on the speed control shaft is quite tight, so it requires good torque to turn it.

I've seen this problem on many other earlier models too. Ideally, I wish I had a spiked thin steel strip, with spikes on both sides, to put between the collar and shaft before tightening, to dig into the metal to prevent slipping, like a lock-washer.

Ideas on how to prevent slipping? It currently DOESN'T slip. Maybe it's fine, but I want to be more sure. I already THOROUGHLY degreased. I considered a folded piece of sandpaper, but realized it'd just rip the granules off the paper, and let grit into the motor. If I had a big fancy metal-rated high-speed drill, I'd drill and install a pin. Wish I had some fancy tool to score both metal surfaces, like fine interlocking "teeth"... Other ideas?

Thanks,
- Bob

[Brad]

Hi, this is my first post. I've collected 8 windup grammophones since I was a kid, one 78 jukebox, and over 6,000 78's. Hope someone can help me.

Welcome to the forum Bob,

By this point in time, you (like the rest of us) are beyond help

One idea would be to try a little locktite before you tightened the lever onto the shaft. The shaft may be too smooth to get a good purchase, but it may just add enough to solve your problem.

Brad

[Brad]

I just had another thought. How about placing a pin, or small screw next to the shaft where the sleeve opens up to the tabs that hold the tightening screw. This should create a situation, if you used a screw, that the treads of the screw would dig into the shaft and the sleeve achieving the "lockwasher" scenario you described.

Hopefully my crude description makes sense.

[blacknwhite]

I just had another thought. How about placing a pin, or small screw next to the shaft where the sleeve opens up to the tabs that hold the tightening screw. This should create a situation, if you used a screw, that the treads of the screw would dig into the shaft and the sleeve achieving the "lockwasher" scenario you described.

Hopefully my crude description makes sense.

It sure does, thanks for the ideas!

I'll have to order some locktite, it's been recommended before. Sounds like the perfect cross between rubber cement & the old brittle superglue.

Tried idea #2, but there wasn't enough surface area in contact then, so it slipped more.

I did pack fresh grease into the tensioning spring of the speed control shaft, and work it in, so it's actually not quite as hard to turn now. Then re-de-greased the shaft & collar, and scored the shaft along its length with a dremmel bit, and the same for the inside of the collar with a round file; then just brushed them clean, and got it real tight. Seems to work real smoothly now.

Thanks,
- Bob