Cotter Pin Woes

[Nihon_Ni]

I'm working on installing the bolt, castle nut and cotter pin in my RV-8 rudder pedals, but I'm having trouble getting the pin to fit into the slot. After almost an hour of trying unsuccessfully to arrive at a combination of washers that would allow the cotter pin to pass through the bolt and nut, I decided to remove the bolt and test fit the nut and cotter pin. The pin passes through the bolt and nut individually, but when I put the nut on the bold and tightened it as far as it would go I discovered that the nut bottoms out against the unthreaded bolt shank before it has gone on far enough to provide enough clearance to install the cotter pin.

I'm pretty sure I have the right hardware. I checked the measurements of the cotter pin against the Spruce catalog. The 1/16" dia cotter pin will fit, but the 5/64" is specified in the plans.

[IMG][/IMG]

You can see in the picture that the cotter pins won't go in straight, and this is as far as I can insert them. The bottom one is angled worse than the top, but neither will pass through the nut. I've checked it with a magnifying glass, and the castles are aligned with the hole in the bolt (perpendicular to the bolt shank), but the nut needs to turn onto the bolt more in order to allow the pin to clear the castle bottom of the nut. However, the nut is bottoming out and won't turn any farther.

Any suggestions on how to proceed?

Thanks,
Rob

[cjhammes]

Don't over think it. Use the largest dia size that fits and move on.

[aerhed]

Being a clevis head bolt, I bet an AN 320 low castle would line up. Clevis bolts have shorter thread length than regular AN bolts.

[DanH]

Originally Posted by aerhed

Being a clevis head bolt, I bet an AN 320 low castle would line up. Clevis bolts have shorter thread length than regular AN bolts.

Precisely. It's a shear application. Put a shear nut on it.

[Raymo]

Or try the next longer clevis bolt and washers to get the correct alignment.

[az_gila]

It's a typo.

The AN24 bolt spec calls for a hole that is 0.076-0.086 diam.

The 5/64 cotter pin (old AN381 spec) calls for a recommended hole size of 0.094-0.096.

Use a MS24665-132 cotter pin - the 1/16 one.

[Nihon_Ni]

Thanks for all the assistance. I installed 1/16" pins this morning and I'm pressing on with the build.