70sflyer

I have a Cessna 421 Twin built but would like some advice on the angle of the motors.On a electric single motor it is down and to the right but im not sure on the twin​.Thanks

chuckk2

Sheer logic tells me that some down thrust is appropriate. I'd think perhaps less than with a single engine.
Side thrust is a bit more complicated if you consider single engine operation and torque.
Are you using counter rotating motors and propellers? (It's usually a good idea!)

70sflyer

My Cessna dosent have counter rotating props,may go to that.I have a B25 that does have them.It flys good.So right now I have slight down and slight toward the wingtips for each motor.Thanks for your input.

LesUyeda

I did this twin once, and don't remember doing anything special with the motors at all.

Les

flyinwalenda

My Feedback: (5)

I have an electric C47 and the firewalls had down thrust built in. I removed it so the motors have no side or down thrust now. It seems to fly better this way. I also have counter rotation set-up.

LesUyeda

I went back and looked at the plans for a Royal B25 I started once upon a time, and it indicates 5 degrees right thrust on the right engine, but I can find nothing for the left engine. Must be determined by the engine mount parts.

Les

70sflyer

Thanks for that Les.

OldScaleGuy

My Feedback: (2)

If this helps, i am putting together my second Twinstar. The left hand motor has left thrust, the right hand motor has right thrust. Looking at it i would guess it is 3-4 degrees, definitely noticeable. Number 1 flies great with that arrangement.

LesUyeda

pfifft6

OldScaleGuy

My Feedback: (2)

Les, i think so, at least with the Twinstar i believe that was one of Hobbico's goals to have it manageable with an engine out. I have had a dead stick a couple of times with Twinstar number 1 and was able to land without any problems. I had a 101" Ziroli B-25 the engines were set at 0/0 and it flew great, never had a dead stick with that plane though.

chuckk2

Are you using counter rotating motors and propellers? (It's usually a good idea!)
A bit of amplification. Normal rotation on a single motor model causes a turn/bank due to torque.
When thinking about a twin, I'd guess that normal rotation should be on the left wing (flying away from the TX),
and counter rotating to the right. This has to do with the center of mass and the arm length between it and the motor.

Geebeefanatic

My Feedback: (2)

I have had great success with my Curtiss B-2 with over 200 flights using two degrees down thrust and two degrees out thrust on each engine towards wingtip. This is to help with an engine out condition.

Big Oakden

My Feedback: (3)

when i built my Twin Stick. i made them straight, figuring i could adjust with a small washer behind the motors