Attach Prop to Motor Output Shaft?? (maybe stupid Q)

[dosco]

I'm considering building a small, simple, electric-powered aircraft to build my RC flying skills.

Not ever having built an electric RC plane (or car or boat) ... and recalling toying with electric motors when I was a kid (I'm 51 now).

How does one affix a prop to the motor's output shaft?

There aren't any key slots or flats, so I'm confused. Am hoping someone with experience will set me straight.

Best-
Dave

[ffkiwi]

There are a variety of adapters on the market allowing you to fit a propeller to an electric motor shaft-anything from about 2mm up to about 6mm motor shaft size. The very smallest motors-with 1mm dia shafts or slightly larger generally have props that simply push on, as a tight friction fit.

The purpose built prop adapters essentially come in two basic types-those which use a set screw to lock them on the motor shaft, and those which use a tapered collet along with a collar which screws down to tighten the collet-think of a drill chuck style of operation. These types in turn may have the prop itself retained by a prop screw, by a nut, or by a spinner nut-the first option obviously having a female thread  on the prop side of the adaptor, the latter two a male thread.

You might still have to obtain some prop bushings or alternatively drill out your chosen prop hub to get a good fit on the adaptor, depending on the prop end dimensions...

Do a search on 'prop adapter' on Ebay or elsewhere and you will throw up a range of options. If you have a lathe, the set screw retention types are easy enough to make-the collet types require significantly more work to make your own...

 ChrisM
 'ffkiwi'

[Starduster]

Hi Dosco - i've got a bunch of collets in my box. If you can let me know the diameter (and length) of the shaft, I might have one.

[dosco]

So here's what I bought (and arrived the other day) ... a 10g brushless outrunner motor 1811 2000KV. It arrived in a mailing pouch and no instructions or data sheets.

In addition to "how do I attach a prop" I'm also not clear on the supplied hardware. There is a little widget with gudgeon screws, and also a spinner. There is an o-ring that's sizeable, not sure what that's for. Finally, there is nothing about the wiring, and all are black colored. Yes, I need an ESC (will be ordering that soon).

Below is a pic from the Amazon page. I spent maybe 10 minutes on google trying to find tech data ... no joy.

Best-
Dave

Attach Prop to Motor Output Shaft?? (maybe stupid Q)

[VictorY]

The spinner looking thing is a prop adapter that clamps on to the motor shaft when you assemble it with a prop, slide the assembly down over the motor shaft and tighten the spinner/nut by sliding an allen wrench or piece of stiff wire through the hole drilled in it and twisting.

The other adapter is a soft mount prop adapter, or prop saver. Slide the adapter over the motor shaft, aligning one of the two bolts with the flat spot on the shaft and tightening it. Then tighten the other bolt to complete adapter installation. To mount the prop, you will probably have to ream the prop until it is a press fit on the adapter, then stretch the o-ring from one bolt to the other across the front of the prop hub to mount the prop. It seems like it would just come flying off but it is a very good design if the prop fits tightly on the adapter, and saves a lot of props on smaller planes that have no landing gear.

[Kevin M]

The ESC should come with sockets already fitted to its 3 leads that connect to the motor, and also there should be supplied 3 matching plugs for you to solder to your motor wires. Normally they supply some suitable heat-shrink tubing as well. Plug the three motor wires into the ESC sockets any way you like, then power up the motor. If it rotates in the wrong direction, unplug any two of the motor wires and swap them over.

[dosco]

VictorY:
Thank you for explaining that ... super helpful!

Kevin M:
Any tips on sizing the ESC? I haven't pulled the trigger on a purchase yet, as I'm not clear on which one to buy.

Best-
Dave

[VictorY]

To determine which ESC is best, you need to know what voltage you plan on running and about how many watts or amps you will be drawing with the prop you are using.

[Kevin M]

Dosco,

It depends quite a lot on the prop you are going to use, if you could provide a few more details of the model, its size and projected mass, and what prop pitch & diameter you plan to use, it would give a clearer idea of what would be a suitable ESC amperage.