Correctly mounting prop to motor shaft

[Horty]

I recently bought a smaller motor for a delta wing and it didn't come with a prop collett. Instead the end is threaded and it came with a nut that fits the threading. The props that I got came with prop adapters but none of them fit it perfectly and therefore the prop is slightly off center. Am I missing something here? How am I supposed to center the prop on the shaft without a collett? All of the other motors I have came with a collett and I found an adapter that fits pretty close and then the collett takes up the slack when I tighten it down. The colletts for the other motors don't fit this motor b/c the shaft diameter is too small. Any suggestions?

Is there a key to ordering props based on the prop shaft diameter? I don't think I have seen that as a metric before.

 

[BenMadrigal]

its possible yet uncommon in metric. if it's not just convert, it takes seconds

 

[iwlf]

Your prop should have been supplied with a series of graduated rings that fit in the recess at the back of the prop hub. One of the rings is correct for your threaded prop shaft and should center on the shaft when installed.

 

[grandpa55]

I have same problem. I am just getting back into the hobby and am finishing a nice bulsa plane I got years ago. It came with motor and ESC, I had to get servo's, battery and prop.

The props I ordered came with two spacers that insert into prop to give a snug fit on prop shaft of motor. Unfortunately, neither give a snug fit and even the smallest gives a wobble.

Do I return the props (I ordered spares) or can I get the correct spacers for the props separately?

 

[Gazoo]

Some of my motor/prop combinations have the same issue. I glue in the smallest adapter ring into the prop and then drill it to the proper size. If you don't glue it in, it will spin when drilled. Find the bit that fits into the undrilled hole and then use the next size up. Then the next size up and continue doing this until the hole is the correct size.

 

[grandpa55]

Thanks for the quick response Gazoo.

The spacer (or bushing) fits into the prop OK. The problem is that even the smallest bushing is too loose on the motor shaft. So it's not a matter of drilling out the center to get it to fit (it's already too loose on the shaft) it needs a smaller bushing to hug the shaft.

(From memory I think the smaller bushing size was 0.186, and the motor shaft is 0.13... The smallest hole is too big for the shaft).

Can these bushings be bought separately?
Is there a difference in shaft size for slow flyers than other models?
I've seen pics of some props that come with 6 bushings, mine only came with 2. Difference in quality and manufacturer?

I've been reading about prop converters and other devices.
Some threads about putting tape, plumbers tape etc on the shaft to build it up. Anyone recommend this?
Getting way too complicated just to get a prop on a motor!

 

[Gazoo]

If the motor kv is not too high and it isn't super powerful, you may want to use a prop saver instead of mounting with a nut or collet.

I like to use them on B-pack or similar setups. Most have steps in them for multiple prop hole sizes. I picked mine up here.