Posted: Fri Mar 21, 2008 12:19 pmIf I add a set of redrives to my R 185s...
will I need leading edge doublers and other modes to the wing?
will I need leading edge doublers and other modes to the wing?
the consequences of adding a redrive:
1. thrustline is lower, so the distance between where the torque from the thrustline is applied to the wing goes from ~0 (bi-props centre is right in the middle of the Dcell vertically) to a distance of about 6" from the hung redrive prop (1/2 the diameter of small pulley + 1/2 diameter of large pulley + pulley gap)
2. overall thrust increase. due to the prop turning more slowly it is more efficient and so provides more thrust at all speeds provided the 185 can still churn away at hopefully 5800rpm (normal bi-prop rpm)
To add a redrive, at a minimum I would add the D-cell skin doubler (4' section) and convert to the long bolt modification. The skin doubler will help distribute the added torque of the offset thrust centreline which acts to twist the D-cell around the nacelle attach points. The longbolt mod will help distribute the now uneven shear forces on the attach bolts. This mod incorporates plates on the top and bottom of the wing which also helps distribute the load the nacelle puts on the wing - essentially making the nacelle wider.
that's my best guess!
Tyler