Online Community of Zenith Builders and Flyers
I'm helping a buddy restore a '48 Stinson. Recently, he attempted to order a "B-Nut" from Spruce to clamp or terminate the mixture cable. For those not familar, a B-nut has a shaft to rotate in a control arm such as a throttle or mixture arm. The solid steel cable passes through a hole in the nut and is secured with a set screw. Looks like this:
Spruce told my buddy that they are now out-of-stock and don't expect to get any more. Apparently only one vendor supplied these and he is deceased!
Does anyone know of a good alternative and source?
Did a quick search and page 18 of this catalog Control Products Catalog seems to show them. They look like a connection I have seen on control cables for trucks before.
I usually make my own with a AN3 or AN4 bolt with the cotter pin hole...run a fiber lok nut down the threads, insert the cable thru the cotter key hole, then back the nut out against the cable. Many variations possible with the same basic principle to fit the application you're working on. Can also thread a small tube, drill a hole in it, insert the cable in the hole and run a bolt down the tube against the cable. etc etc
I like those big tailed Stinsons. . . .
My 1947 Stinson 108-2 has a homemade connector on the mixture arm using a drilled shaft AN bolt, the hole is drilled near the end of the threaded area and a washer and nyloc nut are clamped down hard on the cable where it goes through the hole. The unthreaded section of the bolt (closest to the head of the bolt) provides a surface to ride in the hole in the mixture control arm. There is a flat washer under the head of the bolt and between the cable and the mixture arm (in other words, a flat washer on each side of the mixture arm). I have owned the plane for over a decade and it came to me with that attachment method, don't know how long it was used before I had the plane. Still works great.
However, if you want a "bug nut" on the cable end, try Van's Aircraft, the folks who manufacture the RV line of homebuilt aircraft. They sell lots of nicely made parts that can be used in many homebuilt aircraft and can also be used in certified planes if you make sure it is a suitable part. Here is their cable end "bug nut".... https://www.vansaircraft.com/cgi-bin/store.cgi?ident=1452206902-116...
The Stinson had a connector exactly as you have on yours - it was just too beat-up and bent to reuse. My friend tried drilling an AN-3 bolt to make another but has mostly just broken a bunch of drill bits! :>(
Spruce sells a drilled bolt for the same use and it is very inexpensive (50 cents! What can you get for 50 cents any more?) so we've ordered a couple and see if they'll work. If not, the Van's part looks like it will work if the shaft on the nut is 3/16".
John, What did you end up doing? Wondering if you purchased one from Van's and if it has a3/16" shaft? I need one for my parking brake valve. Thanks, Ron
Glad to help, John. Anything for a fellow Zenith and Stinson person!
By the way, I bid on your Relief Band on Ebay for my Daughter to try, she gets airsick very easily. We'll see if I win the auction and if it helps her.
Thanks for bidding and good luck!