I have been working to resolve a problem for more than a month now and thought I would query the group for a possible solution. 

 

If anyone else is running (or planning to run) a 3-blade M/T electric prop with the RD-2C gearbox, I have discovered a mating problem in using this prop/gearbox combination for my 20B.  The problem is the RD-2C prop flange comes with 3/8 id x 5/8 od bushings.  The M/T prop has a stepped hole that is ¾” for the first 3/32” and then goes to 5/8”.  Tracy is not comfortable with drilling out the 5/8” bushings and M/T adamantly advises against using anything less than ½” prop bolts with this prop.  So, I’m at a standstill until I can get this resolved.  The only solution I can see is to press out the existing bushings and open up the holes to accept ¾” od x ½” id bushings.  But that would require disassembly of the gearbox and some precision machine work, possible but not my first choice. 

 

Mark S.

Lancair ES – 20B

(with a very pricey lawn ornament)