PSA- Propeller testing

[ofiesens2]

Hi all,

So last spring I received an order from Hobby King that sent me counter rotating props instead of the conventional direction. I hopped onto the forums, asked if they would work on my power pack C (The Beef) motor after switching the bullet leads to make it spin the right direction. And the answer I got was "no, you need the motor to spin the same direction of the nut holding the prop on so it doesn't fly off." Well, I was a bit dubious because twin engine planes use 2 props spinning different directions, but the same 2 motors, and there are no prop nuts flying off on all of the twins that I see. So I decided to test it out in my bedroom. Here's a quick video of the result.

https://youtu.be/sfY8WOO2QrU

Needless to say, the nut flew off as I was told it would, and so did the prop. I used a thick blanket to try to catch the nut and prop when they flew off so they wouldn't disappear into the dark recesses of my room. The prop got caught fine, but the nut bounced off the blanket, and I never saw it. I heard it hit the map on my bedroom wall and bounce away, but after an hour of searching it is still gone. So now I'm out of a nut.

So besides that story, how do twin engine planes like the FT Cruiser and Guinea keep their props on if the motors and props are spinning different directions on the left and right of the plane?

TL;DR
Don't use a CW rotating prop on a standard motor with a nut holding it on. You will loose the nut.

Hope you all enjoyed!
--Ethan

 

[ElectriSean]

Use Nylocks.

 

[ofiesens2]

UPDATE- Found the nut!
Also, does lock-tight work instead of Nylocks? I also feel like there should be a more streamlined way of doing this... like motors prebuilt with the screw already spinning the other way.

 

[ElectriSean]

Locktite would work as well (only use the blue!) but it's messy and gums up the threads. Nylocks are clean and reusable, and if you always buy CCW motors, easy to source.

 

[ofiesens2]

Alright, got the nylocks, but what is the best way to put them on? I'll have to use a wrench and there isn't really a good place to hold the motor to keep it still while I twist on the nylock.

 

[mikeporterinmd]

You can't just grab the motor bell? Or it is slipping?

Mike

 

[Snarls]

First make sure you have the correct size. Nylocks can be hard to put on the first time because the threads have to cut through the nylon. If you have one of those rubber jar lid grippers you can use that, otherwise a piece of rubber helps grip the motor bell. Then just take your time and slowly screw the nylock on. Subsequent screwing ons of the nylock should be easier.