P901
Heliman
Location: Southwick,MA
| Had a unacceptable imbalance even after doing the CG and total weight method and came up with this procedure to static balance the three blade head.
Spool up to center the blades in the grips and let the head slow
down and stop without touching it. Then tighten the blade screws to hold the blades in place without any "lead/lag" movement.
The balancer pointer is suspended first without the head and the reference mark is made on the paper. Then install the complete head/swash assembly on the pointer shaft. In this case the pointer was now off by 3/4" at the beginning of the balancing process !
Cutting the balancing tape by 1/4" increments will get the point right on center.
The blades all weighed 98grams on a digital scale, possibly a better initial result might have been had with a scale that went to tenths of a gram but this method balances the complete assembly all at once and saves the pitch settings since the whole assembly is removed from the mainshaft as one unit.
The machine is a Hirobo .30 Schweizer converted to electric, full description under "Hirobo Schweizer Conversion" in Electric conversion postings.
Comments/suggestions please.
P901
        
andrew |
