Better hinge pin top cowl <--> airframe

[jdeas]

The current .09 pin Vans supplies allows for too much play in the top of the cowl so before I finalize the shims I want to replace the .09 steel pin with a tapered .125 wire.



Can someone here give me an ideal of the suitability of using 303,304 or 305 stainless vs 1080-1085 piano wire (spring) to create the new hinge pin?
I am leaning toward the piano wire given its spring qualities may keep it from bending as easy on repeated installations. Piano wire also appears to come in more sizes so I could go down to a .110 if need be.

 

[JonJay]

You can easily make the taper hinge pin

My neighbor buddy did this but I can not find the post. Basically he used the appropriate pin and chucked it up in a drill then ran it past a disk or belt sander until he had the desired taper. Worked very well for him. He used the standard stainless pin that Van's supplied for that particular hinge.
Sorry I can not answer your other questions on suitability of piano hinge.

 

[HFS]

Drill Rod

Drill Rod is a heat treatable steel with around a 50KSI yield strength in the untreated condition - the reason it is called drill rod has nothing to do with drilling, but the fact that it is available in AWG sizes, just like your 1-60 drill index. Using drill rod (typically comes in 3' lengths - from McMaster-Carr) you can move up or down in diameter in steps of no more than a couple of thousandths of an inch. It doesn't take well to being installed with a drill motor, but you can size it so it can be installed by hand and still "firm" up the joint. I have used it on two different RV's - a -4 & an HRII for over 2500 hr. of flying time and have never had a failure. Over time as the pins/hinges work themselves into a comfort zone and begin to loosen, you can jump to the next larger diameter and "tighten" everything back up again. Drill Rod - give it some thought.