I started with two Fox bellcranks. Drilled the centers out to 5/32", as it was sloppy on 1/8" wire. Then I cut a brass tube bushing to make it work with 1/8" wire.
Three more pieces of 5/32" brass tubing, as close to .095 as I could get them, and 4-40 hardware to fasten at the leadout and ball link connection points.
The leadout wire goes through 1/16" brass tubing that had previously been heated with a torch to facilitate bending. With two inches of wire sticking out of the end of the one inch tubing, I bent the tubing around a piece of 1/8" music wire until it had a lightbulb shape, spread it a little so it fit around the 5/32" brass tubing, wrapped with copper wire, and applied heat shrink. Bolted it all together with nylock nuts.
The 1/8" music wire post is supported top and bottom by 1/8" ply. Duracollars hold the post in position inside the two ply plates, and one more collar holds the bellcrank in place. The music wire extends through both ply plates and stops just shy of the center sheeting.
The only problem area I can see is the brass tubing on the leadouts rubbing on the brass tubing sandwiched between the bellcranks. Because the screws are tight, the sandwiched tubing is held fast and can't turn like a bearing. But I think that arrangement is better than the leadouts rubbing on the screw threads.
Other than that, I think it's bulletproof.
I know, a 4" Bellcrank would be preferable, but I have several of the Fox bellcranks on hand, so I thought I'd try to engineer me something.
It's going in a Banshee.
Thoughts? Comments? Recommendations?

I like the spacer under the ball link, you make that?


MM

No, those little cones are included with the Dubro ball links. They even give you 4-40 screws and locknuts.

Now Avaiojet, aren't you the one that showed us that trick.  I did it with 2 Perfect bell cranks as that is what I had and didn't like the idea of a single Perfect bell crank the plane it went in.   I thought I had a picture of my set up on here but can't find it.

The advantage is it's more work and cost 4 times as much plus it'll stand a 500 Lb pull test.


MM

... and I believe Jim said he had those bellcranks on hand, so material cost = (not much more than) $0

The advantage is it's more work and cost 4 times as much plus it'll stand a 500 Lb pull test.


MM

The plywood will fail long before we get to 500 lbs.

Try This:

I like it! Bicycle chain quick release links?

I prefer metal-plastic pairs, everywhere if possible. Never metal-metal, thinking on the wearing without lubrication and the vibrations. Mostly at invisible parts, like the bellcrank.
In the ancient times we used 8 mm ( 1/3" ) textile-bakelite (Novotex, Textolite etc.) Now I prefer ZX-100.
Looks primitive, but I have some, older than 20 years and 2000+ flights, without any wearing. See:

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089448145107762?pid=5715089448145107762&oid=117790355930193335731

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089525767871586?pid=5715089525767871586&oid=117790355930193335731

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089533111614258?pid=5715089533111614258&oid=117790355930193335731

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089616610138770?pid=5715089616610138770&oid=117790355930193335731

... and I believe Jim said he had those bellcranks on hand, so material cost = (not much more than) $0

How did he get them on hand without buying them?

2 Fox = $16
2 Perfect = $5.64
1 Brodak = $4.99


MM

How did he get them on hand without buying them?

2 Fox = $16
2 Perfect = $5.64
1 Brodak = $4.99


MM

I did in fact buy them. About 30 years ago I bought a bunch of them. I was all into speed limit combat then, and building foamies in bulk. I don't remember what they cost back then, but at this point it doesn't matter.

I prefer metal-plastic pairs, everywhere if possible. Never metal-metal, thinking on the wearing without lubrication and the vibrations. Mostly at invisible parts, like the bellcrank.
In the ancient times we used 8 mm ( 1/3" ) textile-bakelite (Novotex, Textolite etc.) Now I prefer ZX-100.
Looks primitive, but I have some, older than 20 years and 2000+ flights, without any wearing. See:

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089448145107762?pid=5715089448145107762&oid=117790355930193335731

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089525767871586?pid=5715089525767871586&oid=117790355930193335731

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089533111614258?pid=5715089533111614258&oid=117790355930193335731

https://plus.google.com/photos/117790355930193335731/albums/5715088163776972593/5715089616610138770?pid=5715089616610138770&oid=117790355930193335731

Nice work!