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        Discussion FMS Focke Wulf Newbie Question (please help)

#1 cneuhauser Jun 30, 2012 09:08 PM

FMS Focke Wulf Newbie Question (please help)
 
My question is...

Is the motor supposed to be angled down and slightly to the left of center?

#2 gnats82 Jun 30, 2012 09:18 PM

Quote:

Originally Posted by cneuhauser (Post 22042061)
My question is...

Is the motor supposed to be angled down and slightly to the left of center?

For this and most all WWII fighters, the motors are set up with some down thrust and right thrust (as viewed from behind). This a a technique that offsets the tendency to pull to the left under high power settings, especially at take-off where that reaction can result in damage to the model if the pilot doesn't give adequate corrections to keep the model's take-off straight and it wrecks.

It also helps offset the tendency to climb more than desired when a high power setting is given in flight.

#3 cneuhauser Jun 30, 2012 09:20 PM

Kind of like torque steer in a car....nice...awesome!

#4 gnats82 Jun 30, 2012 09:24 PM

Quote:

Originally Posted by cneuhauser (Post 22042146)
Kind of like torque steer in a car....nice...awesome!

Well, kinda, yeah..! No stranger here to torque steer, used to drive two-stroke SAABs and DKWs, waay (??) back in the day..;)

#5 HoosierGuy Jul 02, 2012 03:58 PM

Quote:

Originally Posted by gnats82 (Post 22042124)
For this and most all WWII fighters, the motors are set up with some down thrust and right thrust (as viewed from behind). This a a technique that offsets the tendency to pull to the left under high power settings, especially at take-off where that reaction can result in damage to the model if the pilot doesn't give adequate corrections to keep the model's take-off straight and it wrecks.


Is that only for WW2 fighters or do most R.C. planes have that down and right (viewed from behind) angle? What about R.C. electric gliders and planes with the motor on top like a pusher glider?

#6 gnats82 Jul 02, 2012 08:36 PM

Quote:

Originally Posted by HoosierGuy (Post 22056120)
Is that only for WW2 fighters or do most R.C. planes have that down and right (viewed from behind) angle? What about R.C. electric gliders and planes with the motor on top like a pusher glider?

Yes, it's a pretty standard practice to have the down/right thrust angles built in on tractor prop installations of R.C.planes of most types. However, the smaller the prop is in relation to the wingspan and fuselage length, the less offset is needed and none at all is present or needed on some planes.

Pusher installations can have thrust adjustment angles built in also, according to the prop rotation and how far above the wing center line it is.

It often gets some attention on the warbird threads because the prop diameter is larger in relationship to the wing span and with appearance being a big part of the attraction to warbirds, it's easier to notice. Some thrust angle offsets were used on the full scale planes though I can't think of a fighter that used offsets to the side.

Also, most WWII fighters had positive wing incidence on the order of 1.5 to 2 degrees, a few with a tad more. This effectively causes down thrust on it's own though added motor down thrust can be seen on some like the Merlin powered P-51s and the F6F Hellcat.


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