Specs Please

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glasscamper
Posts: 8
Joined: Mon Jul 05, 2021 1:22 pm

Specs Please

Post by glasscamper »

I am setting up a Piet for flight. I am not the builder.

What is the flying wire tension spec? I bought a tension gauge and would like to be sure.
google suggested this: https://acropilotbret.wordpress.com/201 ... ing-wires/

My plane has a tapered shaft C65 engine. What is the torque for the prop hub nut?

SERVICE BULLETIN 227B
The torque value for fixed pitch metal McCauley propellers is based on the
propeller mounting bolt size.
For a 3/8" prop bolt, the torque is 25-30 pound-feet or 300-360
pound-inches.
Continental Engine Tapershaft Propeller Hub Torque
Torque for the taper shaft propeller adapter is located in the A-65, 85, and
O-200 manual. Section 6-4 Propeller Installation.
The torque is 200 to 225 FOOT-Pounds for the center retaining nut with the
(4) holes in it.
IE using a 3 foot bar, Pull approximately 70# for full tightness of the Hub
on to the tapered crankshaft.
These hubs should be inspected at each removal for cracks in the hub at the
keyway and between the lightening holes. These cracks propagate quickly and
can result in catastrophic failure. The hub cracks can be induced by over
torquing the hub to the crankshaft.

so 70lb x 3 ft = 210 ft-lbs--is this how y'all do it?
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taildrags
Posts: 637
Joined: Tue Mar 07, 2017 10:39 pm

Re: Specs Please

Post by taildrags »

Yes, that's one way of doing it with a wrench, some spring scales, and a 3 ft cheater bar. That is, unless you have access to one of these (like I do)-
torque_wrench.jpg
Oscar Zuniga
Medford, OR
Air Camper NX41CC, A75 power
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