DanNiendorff
Well Known Member
I just finished up section 23 - the aileron actuation. I think there may be a little room for improvement in the methods for fitting the torque tube (pg 23-07), so I though I would post an alternative method for future builders to consider. Some builders may already be fitting it this way, but I could not find any post on it, and it is not referenced in the RV-14 Wiki, so here it is......
The step consists of fitting the two torque tube ends (CS-00009 & WD-1014) onto a central joining collar (CS-00009b). The instructions guide the builder to make the sum of the three joined sections equal to 451.2 (+/- 0.4) mm. Depending on available tools, that degree of precision might be a challenge. The tube ends will seat in bearings on the front and rear spar, with any error in length requiring a washer shim to minimize unintended forces being applied to the spars. Of course the washer shim sizes are limited to 0.063 and 0.032 which is probably fine. But why setup for measurement error and then correct it?
An alternative method would be complete the CS-00009 and WD-1014 (ie: rivet in the rod ends), and mount them into the wing root with the undrilled CS-00009b nesting between them. The CS-00009 and WD-1014 rod ends would then be secured to the bearings with nuts, and the CS-00009b could be match drilled in place, with its length perfectly defined, which would eliminate any shims, and guarantee no unnecessary stresses applied to the front and rear spar.
Using this method would make clocking the CS-00009 and WD-1014 slightly more difficult, but not extremely so. The current instructions provide for a flat surface and a spacer block to define the clocking. If done in place on the wing, a flat piece of plywood with a cut out for the spar and a spacer block glued or nailed in the right place would do the exact same thing - just in a vertical plane rather than horizontal.
Anyhow - this is how I would do it if I did it again. The existing method worked out for me fine. But I think this way is more likely to guarantee a good result. Just my two cents.
If others agree that this would be worthwhile, perhaps it could be added to the RV-14 Wiki.
The step consists of fitting the two torque tube ends (CS-00009 & WD-1014) onto a central joining collar (CS-00009b). The instructions guide the builder to make the sum of the three joined sections equal to 451.2 (+/- 0.4) mm. Depending on available tools, that degree of precision might be a challenge. The tube ends will seat in bearings on the front and rear spar, with any error in length requiring a washer shim to minimize unintended forces being applied to the spars. Of course the washer shim sizes are limited to 0.063 and 0.032 which is probably fine. But why setup for measurement error and then correct it?
An alternative method would be complete the CS-00009 and WD-1014 (ie: rivet in the rod ends), and mount them into the wing root with the undrilled CS-00009b nesting between them. The CS-00009 and WD-1014 rod ends would then be secured to the bearings with nuts, and the CS-00009b could be match drilled in place, with its length perfectly defined, which would eliminate any shims, and guarantee no unnecessary stresses applied to the front and rear spar.
Using this method would make clocking the CS-00009 and WD-1014 slightly more difficult, but not extremely so. The current instructions provide for a flat surface and a spacer block to define the clocking. If done in place on the wing, a flat piece of plywood with a cut out for the spar and a spacer block glued or nailed in the right place would do the exact same thing - just in a vertical plane rather than horizontal.
Anyhow - this is how I would do it if I did it again. The existing method worked out for me fine. But I think this way is more likely to guarantee a good result. Just my two cents.
If others agree that this would be worthwhile, perhaps it could be added to the RV-14 Wiki.
