[Oscy]

I am putting together a Great Planes Escapade 46 ARF and notice the engine bulkhead has a significant offset to the right . I am installing an electric motor and am not sure if the offset for electric is required or if I should shim it out so the motor axis is parallel to the fuselauge axis. The offset appears to be about 5 degrees to the right

I'm new to the hobby and this is my first ARF.

Thanks,

Oscy

[rccardude04]

The offset is right thrust to counter the swirling effect created by the prop's airflow disturbance on the vertical tail fin, as well as to counter "p-factor" which is the difference in angle of attack between the climbing and descending blade during the propeller's rotation. Google "P-Factor" and you'll get some good articles I'm sure. It's confusing until you see some diagrams of what happens. But once it makes sense, you'll understand why right thrust is required.

The short answer is that it's designed to be there.

-Eric

[fhhuber]

The offset needed varies with the propeller and engine/motor used. The stock offset built into the Escapade is very close for a typical .46 glow engine with 10X6 to 11X5 prop.

Start with the offset as built in. You may find you want a little more... its unlikely you will want less since the e-conversions tend to swing larger props which will produce more torque and P-factor effect.


the way you find out you need to change the offset is a need to change rudder trim based on throttle. if its just a SMALL amount over the full throttle range, don't bother. If you need significant rudder except at one throttle setting then the offset is wrong. Trim for about 50% throttle and ad just more thrust the direction you have to hold the stick for full throttle.
(this applies to right-left and up-down)

[Oscy]

Originally Posted by rccardude04

The offset is right thrust to counter the swirling effect created by the prop's airflow disturbance on the vertical tail fin, as well as to counter "p-factor" which is the difference in angle of attack between the climbing and descending blade during the propeller's rotation. Google "P-Factor" and you'll get some good articles I'm sure. It's confusing until you see some diagrams of what happens. But once it makes sense, you'll understand why right thrust is required.

The short answer is that it's designed to be there.

-Eric

Thanks for the info...it just didn't look right when i fit the cowling on , but i'll leave it as is and see how it flies. and adjust if needed.

Oscy

[Oscy]

Originally Posted by fhhuber

The offset needed varies with the propeller and engine/motor used. The stock offset built into the Escapade is very close for a typical .46 glow engine with 10X6 to 11X5 prop.

Start with the offset as built in. You may find you want a little more... its unlikely you will want less since the e-conversions tend to swing larger props which will produce more torque and P-factor effect.


the way you find out you need to change the offset is a need to change rudder trim based on throttle. if its just a SMALL amount over the full throttle range, don't bother. If you need significant rudder except at one throttle setting then the offset is wrong. Trim for about 50% throttle and ad just more thrust the direction you have to hold the stick for full throttle.
(this applies to right-left and up-down)

Thanks for the info....And the detail for determining whether I need more or less offset once i have the plane flying.

Oscy

[fhhuber]

Note that 1/2 degree of thrust line change is a LOT.

That's probably 1/2 the thickness of a common 4-40 washer under a stand-off for your model.

A couple of layers of aluminum foil makes a reasonable shim.