TowerPro 5330 Pulling Itself Apart?

[EVTodd]

Ok, I think I may finally have a problem with my cheap outrunner.

Last night I decided to take it apart to clean it and make sure everything is holding up. Bearings are all fine, magnets are still fine, but I noticed something strange. It appeared that the can was pulling itself closer to the front of the motor. Then I noticed this:

It looks like the steel and aluminum parts of the can are starting to separate. Thinking about it, I assume they're just a press fit to each other and there's really not much holding them together.

If it moved it's strange that the magnets are still in place. It almost makes me think that gap has been there since the motor was new but I can tell for sure that the space between the can and the front of the motor is much smaller now (almost touching).

Can anyone else with a TowerPro 5330 check their motor and let me know if they have that gap?

If it's going bad I can't bitch too much. I'm right around 1300 miles with it. Kinda cracks me up though. I was feeling all smug that I never had the magnets move. :lol:

 

[liveforphysics]

I would set it in a cooler with some dry-ice (because the aluminum will contract much more than the steel), then take it out, slather some loc-tite red in the gap, and pinch together in a vise. Then perhaps heating it a bit to make sure the glue is soft so it doesn't crack under the impact of a hammer/punch, and make a few little center-punch taps right on the edge of the steel ring to give it a little mechanical bite to accompany it's chemical bond.

Then go see if you can get another 1,300miles for your efforts.

 

[EVTodd]

I would set it in a cooler with some dry-ice (because the aluminum will contract much more than the steel), then take it out, slather some loc-tite red in the gap, and pinch together in a vise. Then perhaps heating it a bit to make sure the glue is soft so it doesn't crack under the impact of a hammer/punch, and make a few little center-punch taps right on the edge of the steel ring to give it a little mechanical bite to accompany it's chemical bond.

Then go see if you can get another 1,300miles for your efforts.

That's a great idea! I'll have to give it a shot.

It's so strange though. I'm really surprised the magnets didn't move with the can. I just don't get it. I keep looking at it thinking I'm missing something.

 

[EVTodd]

I just noticed Drifter's post about the can on his motor unscrewing itself. Does anyone know if the can on this 5330 is screwed on to the aluminum end piece?

I guess that's possible. Maybe all the epoxy was loose from the steel which allowed the end to unscrew. Only thing is... The motor is spinning clockwise. Hmmmm.

 

[Jeremy Harris]

Both my 5330s have the can tight up against the alloy top flange. As far as I can see, the can is just bonded to the alloy, with the magnets bonded into milled slots in the alloy top piece holding the thing together against the torque loads.

Both my motors had magnets come loose - I'd say that the original bonding everywhere on the motor was pretty suspect.

Jeremy

 

[EVTodd]

Thanks Jeremy,

I was afraid of that. It really does look like the end is just pressed and bonded. I think I'm going to space the motor out a bit, slather a bunch more epoxy on the magnets and see how long it holds. The separation seems to be a slow process so far so maybe with enough epoxy I'll get a few hundred more miles out of it.

I still don't get why the magnets didn't move with it. They're still tight in the milled slots. How in the heck would the can move without taken the magnets with it?

 

[Hillhater]

You may want to look at the way Turnigy have secured the end bell on the 63mm motors using small screws through the casing into the end bell flange ( + epoxy ..i hope !)
Its not the perfect solution, but it would be an improvement.
you could easily do a similar mod , but be careful not to drill into a magnet !

 

[EVTodd]

You may want to look at the way Turnigy have secured the end bell on the 63mm motors using small screws through the casing into the end bell flange ( + epoxy ..i hope !)
you could easily do a similar mod , but be careful not to drill into a magnet !

I was actually thinking about that too. There really isn't much room at all though. I think I'll just see how long it lasts as-is (with more epoxy) and get a Turnigy when it dies. I was actually pretty impressed with the quality of the Turnigy I got for my gf's bike.

 

[drifter]

Have you tried to unscrew the can. My Turnigy motor has a left hand thread, which would screw the motor together when used for turning a propeller, not sure which way your motor is turning.

 

[EVTodd]

Have you tried to unscrew the can. My Turnigy motor has a left hand thread, which would screw the motor together when used for turning a propeller, not sure which way your motor is turning.

I haven't tried it. I actually epoxied up the motor again before I even thought about it.

My motor is spinning clockwise so that could be an issue if it's a left hand thread. I'll keep an eye on it. If (when) it moves again I'll see if it has threads on it.

I may have to consider putting my motors on the other side to avoid that problem in the future.