Taper Pin

[Chucker]

My EAA counselor did not like the fact that my taper pins were not safetied on both sides of the spar....so I started thinking. I also wanted an arrangement that would work with minimum tools. What I built uses a 2-inch extension on the threaded end of the taper pin. I have 3-inch springs that fit over the extension. I cross drilled a hole at the end of the extension for a safety pin. In the photo you will see a bolt threaded into the end of the extension. That bolt is simply a tool for removing the pin without damaging the end of the extension and to keep the pin from finding locations unknown as it comes flying from its nest. The threaded extension will be secured to the pin with red Loctite. The spring and safety pin are not in the photo.

ATB,
Chucker

 

[JoeMartin]

A locknut should be just fine using a taper pin. If the taper hole is correct it will not spin. My snowmobile has over 100 HP and transfers that to the primary clutch that is held on by a taper and also my mill's collets are held in place by a taper. None of these will spin.

 

[Chucker]

No room for a locknut and my inspector won’t buy the “no turn” argument.

 

[Chucker]

Dave put the holes so close to the edge that he had to use 1-1/4" long nuts on the pins. In one location he had to shave the hex off the nut to allow it to rotate. All that aside, this is what I like about the springs and pin approach:

1. No tools required to install
2. Minimum tension on the pins to keep them snug. Hopefully easier to remove.
3. No safety wire to cut and reinstall
4. No spacers or washers required when the narrow end of the taper pin extends beyond the spar carry through. You can always ream a little deeper to clean up the hole and the spring will take up the slack.

If anyone has already tried this approach, I would love to here how it worked for you.

For Fred and other owners with lots of hours on their wings... Have you had to ream deeper due to wear on your spar holes? Just looking at the holes in Dave's wing, it looks like something I may need to do.

ATB,
Chucker