pusher props

[Dillzio]

Hi all. As I consider the purchase of my next plane, i find myself asking a few questions regarding pusher props, i was hoping you guys might be able to help me out.

If you have a rear-mounted engine that traditionally requires a pusher prop, which basically has the blades on the prop twisted in the opposite direction.

Is it essential to use a pusher prop in these applications, or is it OK to use a normal prop, mounted backwards with the engine spinning in the opposite direction to normal? I've thought about it, and by mounting the prop backwards and spinning it backwards it's still doing exactly the same motion as it normally would, only at the back of the aircraft.

The only complication I can see is that instead of the prop-nut tightening itself under power, it would try to loosen itself, so it would probably require double-nutting or using threadlock.

-cheers

[killioughtta]

I never buy push props. I use the method you described. I've never had any issues with nuts loosening up in over a year flying pushers. The only issue would be if you were to use a brushed motor. As you know, the brushes are aligned to run clockwise so, if you reverse the rotation, you might damage the motor or cut its lifespan very short.

One thing to consider with this new plane is prop savers. It will save you so many headaches and you don't need to worry about loose nuts.... however dirty that may sound.

[flydiver]

Pusher props are for twins running > reverse on 1 motor to counteract torque.

Pusher planes (jets, deltas) > mount the prop 'normally' numbers facing forward and turning normal direction.

DO NOT use the brake unless you like to break props unless it has complete ground clearance on landing.

With that weanie little motor a well mounted prop saver is OK. I've been running a 200W Funjet (400W now) with a collet adapter and belly landing it for over 2 years and only broken prop. I use ~100W as a no more prop saver limit.

[killioughtta]

My main concern with not using a prop saver on such a small motor is bending the shaft. Props are $1.50 and 20 seconds to replace. Shafts are $1.50 and 30 minutes (if you're good/depending on the motor )to replace. I still haven't found a 5mm prop saver for the Turnigy and Alpha motors' 5mm prop adapters. I'm not using them on my pushers but I MUST have a saver on the Towerpro bell motor on the Super Cub!

Changing that shaft is still the most dreaded task I've yet to experience in my years flying RC. I shudder just thinking about it.