Pusher prop

[Louis Benjamin]

 Can anyone help?

I am having trouble locating an APC 12" x 8" pusher prop for an E-flite `Deuces Wild` twin motor model. The only place i have found them is on american sites and all of them that do, dont ship international. Is it possible to put a regular 12" x 8" on backwards, as the righthand wing motor will be spinning clockwise?

Thanks

[Andy Harris]

I think you need the proper prop because the leading edge is different to the trailing edge.

Also, you  might be wanting a left hand thread on the prop adapter because of the clockwise rotation.

Regards ....   Andy 

[birdy]

You could try e-flight / horizon for that one. They should know.

[001]

It would be helpful to know firstly, if you are using Electric power or I.C.

If you are using I. C. is the motor timed for clockwise rotation?

According to Sussex Models listing of the model -

Counter-rotating props are available separately, spinners that match the counter-rotating props are included.

[Yorkman]

putting the prop on backwards doesn't change the direction it 'works'-just its efficiency!

[Louis Benjamin]

It`s an E-flite model so its electric. Horizon Hobby U.S list the props and where to purchase (in U.S only) but not on the U.K site. Sussex model centre say they are available but dont actually sell them. In my local model shop in leeds they carnt source them and they even sell the model, so it`s lookin like i`m buggered. 

[001]

Not unknown to convert electric models to I.C. Have you tried Omni Models? They have a good list of pushers..... I used to buy Zinger Pusher Props in bulk from them a few years ago. They were quite happy to export and it actually worked out cheaper than buying them in the U.K.

[Louis Benjamin]

cheers,

just had a look..... but no luck!!!

is there an alternative size i could use where the pusher was more available?

[001]

Louis,

I suppose the answer would be to try your battery/motor/ combination with a Wattmeter to establish which props out of the ones available are most suitable,  then go for a matched pair of tractor & pusher(s)???

How much difference to the handling of the model do you think that having opposite rotation propellers will make? I have never flown a twin (except a Cessna Skymaster, but that doesn't count) so perhaps somebody else would like to comment.

[Louis Benjamin]

According to what i have read...using a counter rotating prop would eliminate any torque issues that would arise .ie the model would fly straighter

[Yorkman]

I've got four all turning the same way....yes, a bit of a swing on initial ground roll, but once flying? Just trim straight and level!

[Louis Benjamin]

cool....might try that then. thanks for your suggestions

[Ed Kershaw]

Micron seem to do them.  I think they're in the Devon or thereabouts.

http://www.micronradiocontrol.co.uk/prop-apc.print.html

Ed

[Louis Benjamin]

excellent....thanks

louis

[Helidel]

Louis,

Hi again, have just read some of your other queries, the Deuces Wild is designed for counter rotating props which will be sold by Horizon (UK) when they eventually get the kits ready for UK.

But with electric, you only have to reverse one of the motors to acheive contra-rotation. This is done by changing over any 2 motor wires to the ESC on one motor, and use a normal prop, then make sure they are both going the correct way!

[Former Member]

[This posting has been removed]

[Helidel]

OOps

Louis (and others) please ignore my 12.23 msg

Having another senior moment having just returned from an exhausting (holiday??)

[Louis Benjamin]

mmmm.....it`s ok helidel, i wondered what you were on about  !! eh eh.

I`ve ordered a pusher prop, but trying yorkman`s suggestion of running both tractor props the same way is an option i might try too.

by the way, does any one know what psi to pump into a airup/spring down retract system?

[Yorkman]

I'm sure that when you had a couple of Merlins or Allisons or some such twirling 16' diameter Hamilton Standards then cancelling out the precessional gyro effect made life a lot easier (any ex Mossie/Hornet /P38/Beaufighter pilots out there to verify?) on takeoff...but I think it's more a case of style over substance with a little electric model....

[Simon Chaddock]

I believe the benefit of opposite rotating props on high power twins is more than just the processional gyro effect. The air mass leaving a prop is rotating. At take off (particularly on taildraggers) the effect of ground drag on this air stream causes it to skew sideways so it hits the tail fin at an angle, hence the need for a boot-full of rudder as you open the throttle. This effect is still there, but reduced, on big 4 engine types so is more easily managed by adjusting the throttle of an outboard engine.

Not quite for the same reason but even Concorde had to limit the power of no4 engine until 60 knots was reached!

[SA Allan]

Graupner makes some pushers for their "super nylon" range , the biggest you can get in a matching clock and counter clock set is 11*8  . You should be able to get them somewere in the UK else I bought mine (7*4 set for a small twin from hobby-lobby) .

http://www.hobby-lobby.com/grprop.htm (scroll down to the bottom of the page ) .

If you only buy the props the postage will make them horribly expensive so you might want to stock up on other goodies .

Hope it helps

[Louis Benjamin]

cheers...thanks for the info

not been a good day today !!

had to dig my e-flite texan out o` the field this mornin.......turns out that the electronic servo reverser that controls the elevator felt like turnin them into ailerons. hard bank to left and knife-edged in from about 150 ft......it hurts 

[Terry Whiting]

Louis,  Why not use a tractor prop...........Looking from the  REAR of your model put the tractor prop on   backwards, now change  over two wires from the ESC to  your motor which reverses rotation, and your tractor prop becomes a pusher..   

[Louis Benjamin]

the leading / trailing edge of the prop would defer from a genuine pusher prop would`nt it terry?

[Simon Chaddock]

Louis

No. A tractor prop fitted backwards AND with a reversed motor is true a pusher because as far as the prop is concerned it is running exactly the same as a tractor. It is just the motor is in front of the prop rather than behind!