motor Angle

[ForceM]

Hi,

I been building a few FT planes for a few weeks now using the downloadable plans.
All is going well except something that keeps puzzling me.
I googled the crap out of it but cant find anything.

Josh is talking here about his motor is "banking to the right .. thats exactly what we want"
Now in a few plans i used the motor pod was also at a weird angle to the side.

Who can explain to me why this is and why i should not just straighten it out?

Also .. i cant wait to actually fly my creations .. build 3 FT planes so far but havent flow them yet.
I build an FT Sea Otter .. FT Explorer .. and putting the finishing touches on an FT Tiny Trainer at the moment.

ForceM

 

[mach1 rc]

The motor angel is because the propeller creates torque one way so you have to turn it the other way. The bigger ones don't need it because there big enough not to be affected by the torque.

 

[mach1 rc]

Oh and welcome to the forums.

 

[ForceM]

mach1 rc .. thx for the welcome.

Unfortunately im not sure what you mean with the torque part.
I think in pictures mostly .. got any graphics that can explain it? .. or a youtube clip.

Also your saying the bigger ones dont need it .. from what size you call them bigger?
I got a Powerpack C single on my FT explorer .. and was going for a C also on my Sea Otter.
The Explorer didnt have any angle.
While the Sea Otter did before i got confused and cut it straight.
I didnt glue the motor nacelle yet so i can rebuild that one when i know why and what i need to do.

 

[Merv]

Here is a FT article that may be helpful

https://www.flitetest.com/articles/what-is-prop-wash-torque-and-p-factor

 

[Paracodespoder]

Welcome to the forums!
The rotational energy of the motor and prop cause the plane to want to roll the opposite direction, this is the torque @mach1 rc was talking about. The angle on the pod negates that force.
On the sea otter, cutting it straight will not work! The location of the motor requires that downward (or is it upwards, don’t remember) angle, without it the plane will pitch violently down (ask me how I know 🙄).
I believe the explorers has it as well.
Planes such as the normal size ft mustang, mig 3, storch, etc. don’t really need it. (They do, but not nearly as bad as the minis and the otter.)

 

[ForceM]

Welcome to the forums!
The rotational energy of the motor and prop cause the plane to want to roll the opposite direction, this is the torque @mach1 rc was talking about. The angle on the pod negates that force.
On the sea otter, cutting it straight will not work! The location of the motor requires that downward (or is it upwards, don’t remember) angle, without it the plane will pitch violently down (ask me how I know 🙄).
I believe the explorers has it as well.
Planes such as the normal size ft mustang, mig 3, storch, etc. don’t really need it. (They do, but not nearly as bad as the minis and the otter.)

Thx now i actually understand.

but !!! .. the sea otter had a sidewards angled power pod .. your talking about up/down angle

 

[ForceM]

The up/down angle is managed (if im correct) by the placement of the nacelle alignment to the rest of the plane

 

[Wildthing]

 

[Piotrsko]

The otter is going to need lots of up thrust to deal with that pylon mount way above the wing centerline, so the motor shaft should point probably at the top of the rudder or higher. It will also need the motor shaft pointing to the right at the same time. If the mounts are set up in an X configuration, on the lower left mount hole there will be about the thickness of a 2-56 nut between the mount and the plywood. That's a starter point for a square to the fuselage motor mount, less if the mount is offset. On my OV-10 in single C pusher mode 11" prop, I had added about 10 degrees up and about 5 degrees right before it flew hands off.

 

[ForceM]

awesome vid.

does that mean torque factor gets nullified on dual prop planes by using cw and ccw props?

 

[Merv]

awesome vid.

does that mean torque factor gets nullified on dual prop planes by using cw and ccw props?

Yes

 

[Paracodespoder]

Thx now i actually understand.

but !!! .. the sea otter had a sidewards angled power pod .. your talking about up/down angle

If you watch the build video it’s not angled sideways, it’s angle up.

 

[ForceM]

rewatching the build vid in a few

 

[ForceM]

If you watch the build video it’s not angled sideways, it’s angle up.

Sorry mate .. have to disagree with you here.
I just looked at the vid .. and rechecked the plan pdf of the motor nacelle ..
it clearly shows the engine being angled sideways .. both on the plan and the vid
To the back right (seen from the back) .. thus creating a thrust angle that should banks the plane to the right

 

[ForceM]

on this one you can see it even more clear