GW

My Feedback: (2)

Ok another question. I did discover the aircraft is a Sparrow.

It only came with Balsa, about 98% of that and I had to fab the rest, and a set of plans. So far I have gotten pretty far and feel pretty good with my progress. BUT I need help. I want to power this electric. With that said, I need to install the fire wall. The way is looks (as if you are in the cockpit looking forward) is it slants back and to the right. Is that correct ? I know there needs to be some slant but I am not sure about the tilt to the right. This is configured as a tail dragger. I was also thinking I would like to put tricycle gear on it. Is that possible or am I screwing with a good thing here?

(Info only: I have been flying some electric foam gliders and a J3 Cub)

This is my first real build. I have a sailplane I am building as well to be an electric glider.

Thanks

GW

Crash-RCU

with the motor mounted to the fire wall you should have some down thrust i.e. the prop is angle down a little, and some right thrust i.e. motor is angle to the right. Motor angled down and to the right probably about 2-3 degrees.

GW

My Feedback: (2)

Thanks for the fast answer. I am not sure how to measure the exact degree on this bit I am assuming its pretty close now and if its to much it can be adjusted with spacers/washers?

Thanks again

GW

Zor

Hello GW,

Some models already have a firewall that povides yaw thrutst angle and down (pitch) thrust angle.

Many models do not have such angled thrust.

It is quite common to use washers (shims) to adjust such angles if and as desired.

Different methods are used to measure these angles.
Some commercially available devices are available on the market.

One method that can be used at home (workshop) is to verify that the leading edge of the wings is square ( 90 degrees) with the longitudinal axis and measure from the prop tips to the leading edge. A simple calculation gives us the angle of side thrust.

A similar methos can measure the downthrust angle (or up thrust) by placing the longitudinal axis horizontal and making measurements from a known square perpendicular to the horizontal.

These angles are not critical and it will not be obvious if there is an appreciable error from any specifications. They are a compromise anyway.and would stand true for only one flight condition which would be a straight and level flight at a specificspeed..

Zor