Propellers too large for shaft? Did not come with any bushings? Is this normal?

snuffy

Member
Hi,

I'm a complete noob, so purchased a handful of props to test from Hobbyking, as I wasn't sure what size I would need.

I'm building the swappable trainer - NTM 26 28 1200KV motor, 3 cell 2200 battery.

Only 2 of the props came with a bushings kit (6x4, 8x4) so I have several props that have an internal diameter too large for the motor shaft. Is this normal not to include bushing adapters? I expected bushings for all the props. Are there bushing kits you can buy with a range of sizes? or should I just scrap what I have and buy props ensuring that they include the adapters?

Cheers,
Tim
 

NewZee

Member
Do the bushings you do have fit in the props that came without bushings? some times you can just swap out bushings, its a pita but works in a pinch! I think the NTM 26 28 has a 3mm shaft which is small some LHS may carry bushings, or I think you can buy them from HK? I don't see a need to toss the props, try and find some bushings.
 

Ron B

Posted a thousand or more times
When looking for props if they don't show the bushing with them then I don't buy them as I have heard that some props don't come with them. I just do this to be on the safe side and if you don't show or say that they come with bushings then you just missed out on a sale.
 

xuzme720

Dedicated foam bender
Mentor
Usually the only props I have gotten with no bushings have a very small hole. So small in fact, that to use them, they need to be drilled out. I'm surprised that yours are that large, but the idea of checking some of your other bushing for fit is a good one.
 

snuffy

Member
So I purchased from Hobbyking:

1x #TP_12x6G/18220 APC style IC Sport propeller 12x6 = $0.99
- Bought this just to see, knew it would be likely too big, 6mm hole diameter, 19.3mm diameter recess on back, and 12.8mm recess on front for a bushing?
1x #OR001-00110A/5512 JXF 10x6 / 254 x 152.5mm Poly Composite propeller = $1.55
- 6mm hole diameter, 9.9mm diameter recess for bush.
1x #074000052/42495 APC Style Propeller 8x4 (2 pc) (UK warehouse) = $2.02
- 6mm hole diameter, 9.8mm diameter recess on front and back for bushing.

(I took the measurements with digital calipers)

The motor I bought I had intended to use with a prop saver, however didn't realise that the prop shaft stuck out of the wrong end of the motor (lesson learned). I therefore had to use the threaded 5mm bolt on shaft and screw down spinner that came with the motor instead.

Vipertech: those are the prop-savers that I bought, but they wouldn't fit the prop saver; the hubs on them are very thick, both in diameter and in depth. The props above seem way beefier (even relative to size) than the 6x4 props that do fit the prop-saver, so think I may inadvertently have purchased some that are made for beefier/higher RPM motors than mine?

Yes, think I'll only buy the ones with the bushing kit in the photo next time.

Thanks for your advice guys.

Tim.
 

snuffy

Member
Hi guys,

I think I have now realised what an electric prop should look like from the images, in particular the smaller diameter hub and bush inserts. I might post a 'how-to choose props' for newbies like me.

Thanks again.
Tim.