Prop adapters spinning off

[DuaneM]

I have 6 Scorpion GAUI motors that have a 17mm x 3mm shiny chromed? shaft and every prop adapter I have just spins off after a few minutes in flight. I tighten these damned things until I break the allen head wrenches I have to use to tighten them (actually broke 3 of them).
I have two types I have used on these motor shafts, one type has the little 2mm allen head stud on opposite sides of each other and a compression type that squeezes the shaft as I tighten the prop.

In my internet searches, I have only found these two types and they always spin off.

Do you know a "fix" or where I could find something better?

I've never replaced a motor shaft, I don't even think it's possible with these motors since I can't even find replacement shafts anywhere. I have been considering filling in the empty space between the shaft and adapter with superglue, but I have no idea if that would just make things worse.

I really hate the idea of throwing these motors away, I really have a hard time throwing anything away!

 

[Jackson]

Are the prop nuts spinning loose? Have you tried Loctite?

 

[DuaneM]

No on the Loctite, I'm worried about getting in down into the windings and it being such permanent attachment. What would happen if I broke off just a part the adapter, leaving the glued on stuff stuck to the shaft. I know I can use heat to soften the Loctite, but what would that do to the insides of the motor?

The prop adapters are spinning off the motor shaft along with the adapter, the little tiny studs and the prop.

 

[DuaneM]

Does a 3.17mm adapter vs a 3mm adapter make much of a difference? The motors have a 3mm shaft and I bought 3.17mm adapters to put on the motors after the factory equipment started to spin off. These spun off a little faster.

Should I just grind a bigger flat spot on the motor shaft and then superglue the crap out of the adapter, then loctite the tiny little super small 2mm studs?

I would hate to have to throw away a perfectly good motor just because I can't find a new shaft to replace the glued up and overly adapted shaft.

 

[DuaneM]

Here's a couple of photos of the crap I'm using:

Original adapters:

The motors:

And the collet type adapters I bought to replace the originals:

 

[Jackson]

The motors have a 3mm shaft and I bought 3.17mm adapters to put on the motors after the factory equipment started to spin off.

Why would you not use the correct size?

All you need is one small drop of blue (medium hold) loctite at the top of the threads. Just keep the Loctite off of the prop hub as it will make it brittle.



You don't need new loctite every time. There are also 5mm Nyloc nuts (check your threads) you can get, but they are a bit a pain to get on when new (at least the ones I have.) I use a little washer with them and some low tech contact cement on the motor shaft to provide a bit of friction for tightening the locking nuts.

 

[DuaneM]

These motors are GAUI and there wasn't a lot of info about them on the internet since they are at least 8 years old. I had to go with one size or the other from measuring the shafts myself. Eyeballing with a metric ruler doesn't show the .17 in the shafts diameter. So I guessed wrong.

I don't have a problem with the threaded part coming loose since I do have the Nyloc nuts installed.

It's the original yellow colored adapters not staying on the shaft. Your ideas with the glue on the shaft will help solve this problem. I'll also try the loctite on the small 2mm studs that tighten (inside the yellow adapters) onto the shafts.

Thank you Jackson!

 

[Jackson]

The medium hold loctite should be in everyone's toolbox.

I have been considering filling in the empty space between the shaft and adapter with superglue,

Too brittle, some glue with a little give makes more sense. I'm also a big fan of Shoe Goo under its various guises.

Good luck.