Remember the days of TV's where they had knobs for changing channels and tuning into drifting stations? On the back side of the knobs, on the plastic that fit tight onto the tuner shaft there was a spring clip, round, that held the plastic tight to the shaft. What is that clip called? I need to find one. I have a bathroom exhaust fan that the squirrel cage keeps slipping off.

 

Looks like ø10mm by 8mm length

 

How about a split-shaft collar (example).

 

Starlock push on fastener. You need the shaft diameter.

 

Spring hose clamp, constant tension hose clamp, spring band clamp.

 

I think I know what you are talking about, a C shaped clip in spring steel that into slots on the knob and grabs a slot in the shaft. No idea what it is called.

Found it C-clip.

eBay

But that will not work, the shaft and knob must be slotted for it.

 

An off-cut of 10mm ID tube might work?

 

There are various kinds of hose clamps that might work. The slots in the fan shaft seem to be designed for that.

 

What is missing from the request is a view of the shaft that shows the portion of the connection that couples shaft torque to the fan blade assembly. In some cases the motor shaft has a flatted section that is intended to lock with a flat area in the plastic blade part, which is hidden from view by the scale held over the opening.
Without seeing the shape of the shaft hat the blade is supposed to clamp on to, how can we guess at the correct choice???

The clamp shown by Mike in post #5 looks like a good guess.

 

Fit the squirrel cage on to the motor shaft then take a photo so that we can see what you’ve got to work with.

 

View attachment 349236

Spring hose clamp, constant tension hose clamp, spring band clamp.

This is what I'm looking for. Thanks

I think I know what you are talking about, a C shaped clip

Those I know. It's supposed to clip into a slot on the motor shaft. There is no such slot.

What is missing from the request is a view of the shaft that shows the portion of the connection that couples shaft torque to the fan blade assembly.

Yeah, I know. I don't have the motor in my possession. It's on my client's work bench. He doesn't know how to solve the problem. If I had a picture of the shaft I'd have shared it.

In some cases the motor shaft has a flatted section

Yes, it does have a flat. But the fan does not. The ID of the fan is circular, no flat. But it is a tight fit now. The clamp is insurance that the fan won't move around on the motor.

This is an exhaust fan mounted in the ceiling in a bathroom. If the fan should drift and jam up then the motor (in the ceiling can overheat) it could present a fire hazard. Doing it right is critical. I can't say this is "Right" but it's better than without the clamp.

how can we guess at the correct choice???

Again, you're right. But MikeA has identified the clamp I'm looking for.

Fit the squirrel cage on to the motor shaft then take a photo so that we can see what you’ve got to work with.

I would have except I don't have the motor in my possession.

 

And just placed an order for 10 of the spring clamps. Only need one but - - - . And I haven't had a need for anything like this since I was a teen messing with TV's (1970's)

 

Crazy glue or epoxy would do the job.

 

Crazy glue or epoxy would do the job.

Yeah, but - - - what about when it comes time to replace the motor (again)?

 

And just placed an order for 10 of the spring clamps.

Those clamps aren't circularly uniform, so you may need a bit of counterbalnce weight added judiciouly, or careful angular orientation, to prevent vibration.

 

to prevent vibration.

Yeah, I'm considering that. But the fan speed is not very high. And given the mass is close to the center line there should be minimal imbalance. If bench testing shows too much vibration I can always grind the tabs off once the fan has been mounted to the shaft.

The clamps are close to what I want. Ideally they wouldn't have any tabs at all. And it's possible the clamp could be installed before the fan is mounted on the shaft "without tabs". Press fit the fan to the shaft. Should run pretty smoothly.

 

The plastic at rest shows about 10mm. I ordered 8mm clamps. Hopefully it's not too tight to get on the fan or to press the fan onto the shaft. If not - I'll order either 9mm or 10mm.

 

FYI: The motor mounts from below the fan (as oriented in the pictures)

 

FYI: The motor mounts from below the fan (as oriented in the pictures)

Does the retaining clip go on the front face of the fan (accessible) or between the fan and the motor (inaccessible).
I think if it is the latter, you will have difficulty getting the fan on to the shaft with a press fit.

I think weight imbalance will not be a problem.

 

The motor pushes through from the far side.

Side note: The motor is a shade pole motor.