Silverhawk Mixture Cable Mounting

[BJohnson]

It is amazing how the little custom details consume so much time. As delivered, my Silverhawk mixture arm needed a modification to the stock Vans bracket. Once done, I connected the Mixture control to the Silverhawk servo when I noticed that my modified bracket put the mixture cable too close to a tube in the motor mount. During start up and shut down, it will beat the mixture cable against the motor mount tube that is less than 1/4" away. There is not much room to move it towards the aircraft centerline or the mixture cable will contact the servo.

It looks like I need to fabricate or modify another bracket to raise the cable upwards with the right angle for the arm.

How have others solved this issue with the mixture cable and the Silverhawk on a IO360? Any tips or pictures would be very helpfull.

 

[Guy Prevost]

I needed a 1" spacer to get the FAB to line up with the cowling anyway. Two birds, one stone.

 

[rv9av8tr]

I would suggest a shorter bracket so the mixture cable is higher, should raise it up and away from the mount...
https://picasaweb.google.com/mikerv9a/FWF#5241649758703412930

 

[aerhed]

If I'm wrong, go ahead and throw stuff at me: Isn't the cable operating backwards? I thought it turned clockwise to enrichen.

 

[roee]

My modification to the bracket is similar to rv9av8tr's. Two bends, simple and effective. But my geometry is slightly different, such that the cable end doesn't have to take much of an angle where it comes out of the fixed end of the sheath. These cables can accommodate some amount of angle there. But I think with it coming out more straight the cable will operate more smoothly, will be less likely to bind, and probably last longer.

About clearance from the engine mount tube, mine has well over an inch. My cable penetration through the firewall is not in the standard location though, so your cable run and engine mount clearance might be a little different.

http://www.kalinskyconsulting.com/rvproj/fiservo.htm

 

[roee]

If I'm wrong, go ahead and throw stuff at me: Isn't the cable operating backwards? I thought it turned clockwise to enrichen.

There is a "reverse mixture" version available, where it's counterclockwise to enrichen. Makes it so you can clock the mixture arm up rather than down. That's what I have, and I'm assuming that Brice has it too.

 

[aerhed]

Alrighty then.

 

[rv9av8tr]

Having the mixture arm version oriented up mitigates the need to make the side cutout in the FAB. But it makes the control rod "approach" more horizontal which requires more bending of that bracket tab. It was a "close" fit for me. As with many things, addressing one "issue" can create one or more other issues.

 

[JonJay]

Having the mixture arm version oriented up mitigates the need to make the side cutout in the FAB. But it makes the control rod "approach" more horizontal which requires more bending of that bracket tab. It was a "close" fit for me. As with many things, addressing one "issue" can create one or more other issues.

I flew mine this way for about 400 hours. I never did like the severe angle of the mixture cable so last year I fab'd up an extension with brace and had it tig welded to the bracket. The alignment is much better now. Not sure what the spec is for the cable in regard to deflection angle but it made me feel better about it. FWIW

 

[BJohnson]

Perfect! Thanks!

Guy, I like your solution, but I think I would have to re-modify my cowling.

rv9av8tr: The pictures help. Looks like all you did was bend the stock bracket to the correct angle. Did you have any issues while bending the bracket?

I'll order another bracket and try this again. Everyone's comments were greatly appreciated. This forum sure helps one stand back and get a fresh look at things.

 

[Rupester]

I also bent the bracket for cable clearance ...

...but I don't think I had to bend it quite as far as you apparently will. Sorry, dohn got no pics.

 

[Guy Prevost]

Guy, I like your solution, but I think I would have to re-modify my cowling.

rv9av8tr: The pictures help. Looks like all you did was bend the stock bracket to the correct angle. Did you have any issues while bending the bracket?

I'll order another bracket and try this again. Everyone's comments were greatly appreciated. This forum sure helps one stand back and get a fresh look at things.

It looks like my mixture rotates opposite the one in the other photos, so some caution would be advised here. My solution might not work for some folks.