| Every time you install your propeller you need to check the propeller for
proper tracking, as in improperly tracking propeller can lead to unwanted
vibration which can lead to excessive wear on engine, gear box, and
airframe components. To properly track your propeller, thread all of the
prop bolts in until they just start to squeeze the prop.
Now with the aircraft on a solid surface, out of the wind, set a chair
or some other fixed object on the ground. Move the rear of the prop blade
so that the tip of the prop just touches it.
Then rotate the prop so that the next blade is in the same position. Do this for the remaining blades if
you have more than a two-bladed prop.
Ideally all blades should touch the object at the tips as they come
around, but if the difference is no more than 1/8", this is
acceptable.
To adjust the tracking on a WOOD propeller tighten the bolt (in
half-turn increments BEING VERY CAREFUL that you do not OVER TORQUE) that
lines up most closely with this blade and recheck to two opposing blades.
Remember that as one tip goes in, the other goes out, so re-measure
both blades each time.
Once the blades all track within limits (do not exceed maximum torque),
tighten all bolts in a cross pattern, 1/2 turn at each time, until all
bolts meet proper torque.
Where available use ONLY the propeller manufacturers recommended torque
values! Here are industry standards torque values for bolts
- BUT these are NOT always what the manufacturer recommends!
1/4 inch bolts = 132 inch pounds plus or minus
10 inch pounds.
5/16 inch bolts=144 inch lbs. plus or minus 15 inch
pounds.
12 inch pounds equal one foot pound. |
