FLAP PUSH-PULL CABLE: JUST "MAKE IT WORK"
Tonight was the first time fitting our cut to length Series 6 flap push-pull cable.
The aft cable attachment bracket is too far forward, where it's too near the aft lift-pin tie-rod for my liking (this is inside the pitch push-rod tunnel on the starboard side).
After I cut off ~ .290" of threads on the aft side of the cable, the aft cable attachment bracket (and self aligning pillow block) is still too far forward.
The overall length of the cable is a tad too short, but screwing in the front and rear fittings only ~ 5 turns seems to make the cable length OK. Really would prefer at least 10 turns though (5/16" x 24 threads).
I "think" I "thunk" up a resolution to just "MAKE IT WORK".
Stay tuned.
Y13-12-04
We mounted the rear cable bracket and my "thunk up" machined parts, so far looks like we can make it happen.
Tonight's snafu was the cable moves the flap cross tube more than the push-rod! I had the flaps set with the push-rod so they were real close to having a 28 degrees throw.
Same adjustment on FL21 and the push-rod is hitting the down-stop (fuse slot) where the push-rod was shy of hitting.
I think it's due to deflection of solid aft mount at extreme ends throwing more.
I think making a new FL21 with between 3/16" and 1/4" less moment should make things happy.
Y13-12-09
I re-drilled a 1/4" hole lower on FL21 between the existing bushing and the edge of the plate and was able to dial in between 25 and 28 degrees.
Hole is way too close to the edge to fly with, will make a new one out of 1/4" 7075 aluminium.
Aft thread extender works great.
Made a temporary front bracket holder to test. Works great.
Ground and reduced aft Heims threads, aft cable threads, front cable threads, front rod end clevis fork threads and coupler threads to 9+1/2 threads of engagement. Once I make a new FL21 with pivot hole mounted a little further forward compared to the redrilled FL21, will have ability to shorten up things by at least 1/16". If I ever needed the ability to shorten further, could remove the stop nut on the Heims or the rod end clevis fork, or both. Without the stop nut, would Redux or Loctite 600 the fitting in place. I would probably be an idiot and somehow get the fitting to bottom out before bonding (by grinding just the right amount away to give proper position) or machining a nut to proper thickness needed.
You need to understand that jam nuts can end up taking the entire load! That's why on something that is torqued down, you install the jam nut first. If it's going to be used in both tension and compression, again keep in mind that the jam nut can take the entire load. That's why you don't necessarily want to thin or use too thin of a jam nut. It can strip/distort, then the connection can loosen.
Y13-12-12
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Full size:
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