Russell Kent wrote:

If you can accurately meaure the diameter (at the tooth tip) and chord length
(distance between the ends of the tooth as projected onto a plane), I can
calculate for you the angle.

Paul Lamar replied:

Good idea Russell. Un wrap it.

Tooth length is 1,72
diameter is 2.08
and gear length is 1.58

I think that works out to 23.3 degrees, making the thrust factor 1148 lbs.  How did you
measure the tooth length?

Here's a different method:
Lightly wet the gear with dirty oil, then roll it on white paper with a hard, flat
surface beneath.  Measure the tooth mark length, then plug it in:

cos-1(1.58 / marklength) = gear tooth angle
tan-1(cos-1(1.58 / marklength)) * 2666 = Finn's thrust

Russell Kent

Thanks Russell. Sounds like a good trick. I used a low cost plastic dial 
caliber to measure it. My mics are up at the hangar.

BTW that was based on 200 foot pounds of torque which is way
more than Finn's engine is generating.
 
Paul Lamar
 
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