Saturday, May 3, 2014

Limb Set #28 Repair Complete

I'll continue with the status of the repairs to limb set #28. So far, the limbs had been reshaped, reglued, and the new limb tip overlays are in place. All that remains is to string them up to check the tiller and rebalance if necessary.  

Last year, I used 10-strands of Brownell Rhino for the string and I never had a failure.  10 strands plus a thin serving left little material in the 1/8" diameter arrow nocks. The new strings I made consist of only 8 strands of Rhino which I hope should hold up for at least a half dozen shots.

In the 1970's, George Alavekiu and Harry Drake were lucky if their Kevlar strings held up for two shots before blowing apart. The new more durable string materials save considerable time and add to the longevity of the limbs. 

I was a little nervous stringing and bracing the freshly repaired bow limbs.  I expected to hear a crack as the jack screws swung the limbs forward, but the only sound came from the string as the tension climbed higher and higher. I rejoiced as it reached the intended brace height. A few quick measurements revealed that the limbs were bending evenly and in perfect unison. 



Next, I carefully began exercising the limbs by drawing them back, letting down, then drawing a little farther.  I continued this process until I achieved full draw. I didn't find even a hint of uneven balance to the bend in the limbs or unusual noise.  The job is complete, successful, and I look forward to shooting these limbs again.  They may have lost as much as two pounds of draw weight, but this is less than a 1% change. In addition, they lost about a half ounce of outer limb mass during the process, which should make them easier on the strings and maybe a little quicker. 

I won't know for sure how the durability is affected until I shoot them.  At the least, the bow limbs are capable of one more shot than they would have had without the repair.