How to measuring incidence angle on firewall
 

Hi Guys,

Please I want to know how do you do to measuring the dowthrust angles e right thrust angles in a firewall with a motor mounted on side and utilizing a Robart incidence meter.I want to measure the angles in a firewall that was not glue in place yet, and I can do moviments in the firewall to correct the angles. There is a suggestion on how I could do that?

Thanks
Érico

RE: How to measuring incidence angle on firewall
 

My suggestion would be to build the firewall square, and use shims under the engine or engine mount to provide the proper angles.

RE: How to measuring incidence angle on firewall
 

Set the model with the horizontal tail at zero incidence. Then mark the front of the fuselage for the amount of duwnthrust you want, and cut to fit.

RE: How to measuring incidence angle on firewall
 

Mike,

The case is that my my model is already build. I buy it ARF and it had a crash, the model had an angle on its firewall, before a crash and the guys ho build the kit don´t put nothing between the mount and the firewall to creat an angle, and I think, if I build another firewall I need to copy that angles, so I email the manufacturer and he tell me the angles. But I have a problem on measuring it, so what I need is how I measure the righthrust and dowthrust angles on that model to copy the angles of original model, before crash.I dont´t want to put nothing between the mount or I have to build the model entirely, because they distribute the angles, by change the sides of the fuselage. Could You help?

Thanks
Érico

RE: How to measuring incidence angle on firewall
 

Thanks, Paul, but if my model is an ARF and it crash, I´m building a new firewall and conserving the sides of the model. How I measure with Robart´s incidence meter the dowthrust an righthrust angles for that new firewall?

Érico

RE: How to measuring incidence angle on firewall
 

I have no experience with a Robarts meter.
I would do the math and find the angles needed, set up the model with the tail horizontal and measure/cut the front end to suit.

RE: How to measuring incidence angle on firewall
 

What model, size (wingspan/area) and engine size ? There are some alternatives to consider.