I'm hoping an 8mm clip can be opened to 10mm and that 8mm doesn't mean the max it can be opened. Otherwise I just bought the wrong size.

This is what I ordered.

 

I'm hoping an 8mm clip can be opened to 10mm and that 8mm doesn't mean the max it can be opened. Otherwise I just bought the wrong size.

This is what I ordered.

It may be marginal.

This is the note from the description:

• NOTE - Please ensure the inner diameter of clips you'll purchase is less than your hose outer diameter(about 1 mm).

 

Think I have to cancel that order and get the 9mm clip. Thanks.

 

Crazy glue or epoxy would do the job.

Been there, done that, no, it did not last!!That was the identical blower design, but on a clothes dryer. The glue will only last a few hours.

 

Been there, done that, no, it did not last!!That was the identical blower design, but on a clothes dryer. The glue will only last a few hours.

Interesting. Was it cyanoacrylate ("crazy glue") or epoxy that failed? The heat and humidity of a clothes dryer probably didn't help.

 

I'm sure you have thought of this, but you may just be able to purchase a replacement fan and motor assembly that fit in the fan housing? I did a search on Amazon "Replacement Bathroom Fan Motors" and got a boat load of different types and sizes. There was even one with a cage blower style and all were not that expensive. Just a thought... Also, I found this that I think is what you are looking for however I think the price is way more than the fan, but...
https://www.allvikingparts.com/PC010007_Knob_Spring_p/pc010007.htm
Good luck...
PS. I did a Google search for "Spring Clip for plastic knobs" and you can find a ton of what you're looking for and not as costly as that link above. Even the same part.

 

Check McMaster-Carr (mcmaster.com), search for "retaining clips". There are many styles and sizes available. "Retaining Springs" could also yield solutions.

 

Are you talking about the kind of "coil spring thing" that goes around the outside of the plastic? I think I know what you mean, as I've seen such things on certain plastic knobs and other similarly attached things (like the fan you show).

But I honestly don't know if you can buy such a thing (at least in small quantities)? About the only thing I can think of that would possibly match or work, would be a very short length "extension" spring (as opposed to a compression spring), with the right inside diameter to fit around the plastic.

Actually, you'd probably want the inside diameter of the spring to be just under the diameter needed; maybe 0.1 or 0.05 mm smaller (?) - to provide a bit more "grip" and to prevent the spring from falling off as you installed it. It would take some experimentation.

You might need to buy a longer spring of such nature, then cut a smaller section from it for your purpose...

 

Strangely, I can't find an example of the kind of spring retainer that I am thinking about; I can only hope I've described it well enough as to what I'm thinking about. Maybe if I have something in my shop, I can go out and take a picture of it.

That said, I did find many examples of this kind of plastic fan being held on by what others have suggested, particularly the tabbed retaining spring clip thing - so yeah, I'd try that first. It's a simple and quick fix, that'll probably work well. It may not be what was originally used, but I think it'd definitely work, after having seen your pictures, and new fans that use them.

Though I wouldn't get too concerned about "overheating" - shaded pole motors I've found, when stalled, just sit there, and get a bit warm, but never so hot as to cause a fire; they're basically a simplistic spinning transformer, with the primary being the outer "C-coil" of the motor, and the secondary being the rotor. The heating, I would imagine, is caused by the "shaded" part, which is just a single turn of "wire" wrapped around one leg of the coil to induce a lag in the AC waveform to make the motor start to spin - which acts as a "shorted secondary" in effect (and causes it to heat up a bit).

If you removed that single turn (virtually impossible in most of these motors), and plugged it in - the motor would just sit there, until you gave the shaft a "spin"; then it would start running, much like an AC induction motor without a starting cap. The neat thing is, just like that non-capped motor, is that you could get it to spin in either direction (in theory, if you could wrap a second single turn coil on the other pole of the motor, and then arranged a switch to short one or the other - you could have a reversible shaded-pole motor - which is probably how the switch in overhead ceiling fans work, but I'm not sure).

But if you trust things better to have a means to allow the motor to spin and not be stalled, go with your gut; ultimately, it's best to repair the motor to work as closely as possible to what the manufacturer intended.

 

Ok - I did find something in my shop - this is on a tuning knob from an old clock-radio. So you can see it's just a short length of extension spring, around four "tabs" that fit around the shaft. In your case, there's only two, and the tabs seem to be made much thicker (which would make sense, given the torque and mass involved). So your spring would need to be stronger accordingly. I do think that the "tabbed spring" hose clamp idea would be best, and I also doubt - as you do - that the tabs would add any extra mass to cause vibration; today, manufacturers seem to be using the same kind of clamps, as I mentioned before, for such squirrel-cage fan mounting, and unless they designed the plastic part to have extra mass in some fashion to balance things, I doubt that it caused them much worry, either, as none of them ground-off the tabs of the spring...

 

Interesting. Was it cyanoacrylate ("crazy glue") or epoxy that failed? The heat and humidity of a clothes dryer probably didn't help.

It was an adhesive made for ABS plastic. And all that it had to do was harden while sticking to the blower wheel material. BUT that was a much more powerful motor, probably 1/4 HP. And the original was just a "push on" install. Certainly a "design for assembly" optimization. The original did outlast the warranty by a few years.
The replacement part had more material in that section.

 

I'm sure you have thought of this, but you may just be able to purchase a replacement fan and motor assembly that fit in the fan housing

Not sure if I mentioned this before but this is a fan owned by my client. He's already bought the new motor, but the fan has lost the clip

I found this that I think is what you are looking for however I think the price is way more than the fan

Yeah, close but no cigar. I haven't seen a clip like that in decades. SEVERAL decades. Well, maybe not "Several" but many decades.

OK, today I received the 8mm clips I ordered from Amazon. DANG the spring has a lot of tension. It will hold confidently. Had to order a bag of 10 of them. Now I have 9 left for who knows what project might come along.

Now all I have to do is return the fan to the motor and hang it in the box.

Problem solved. Thanks for all the input.

 

Ok - I did find something in my shop - this is on a tuning knob from an old clock-radio.

Yeah, I've seen that sort as well. But no - not what I was looking for.

Good news is the problem is solved. But thanks for your efforts. MUCH appreciated.

 

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.
View attachment 349219 View attachment 349220

This is what you really need: it will result in better balance and less vibration https://www.amazon.co.uk/sparefixd-Pressure-Spring-Stoves-142600002/dp/B08GKN9RLX

 

Yes, it would. But: It's done. We're not talking about 5KRPM. Probably 1700 RPM, whatever shade pole motors run at. The amount of dust that collects on the fan blades will be more of a problem than the clip will be. But thank you for the suggestion.

 

Plus:

 

I would think any unbalance cause by your spring clip would be negligible compared to the mass of the blower and its likely intrinsic imbalance.

 

FINAL UPDATE:
The fan has been married to the motor. Bench testing of the motor with the fan revealed a slight vibration WITHOUT the clip. WITH the clip the vibration seemed to disappear. It would seem that the clip offset whatever imbalance there may have been in the plastic fan. The customer commented it seems quieter than before. Happy customer. Happy Handyman (me).

Far as I'm concerned, this thread is done.

 

It would seem that the clip offset whatever imbalance there may have been in the plastic fan

Could be the the imbalance was due to the fan not being exactly centered on the shaft, and the clip firmly centered it.

 

"Perfect Balance" is expensive, while "quit close" is not so expensive. So probably, exactly as "C" stated, the clip holding the fan centered was exactly what was needed.