G-Pete

While searching around for a solution of a servo driven choke I came across some complicated and time consuming builds.

As shorter a pushrod is as more effective they are. Here my mounting on a WH Ultimate. The servo is mounted upside down on a ply 1/8 of an inch thick. I glued it on the motor box and topped with four screws. The rod leads diagonal to the other side to the choke butterfly.
((((To make the job for the servo easier I removed the ball behind the butterfly linkage. To do this, unscrew the butterfly and pull it out. With a magnet you can catch the ball, the spring can stay in place. Secure the butterfly with locktide (very important). The choke moves now freely.)))) (Don't do that!) see next post - I put the ball back in...

No grinding or other butchering is necessary, use nylon ball joints to avoid radiation from the rod.

Transmitter, on my transmitter I choose the trainer switch (Futaba 9CAP) for the choke. Way less chances to hit this switch accidentally, plus it stays not in the on position on it’s own. Now I can kill my engine remotely and apply choke in the starting sequence without any hassle.

Here some pictures…

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G-Pete

rctom

Peter:

I can pretty much guarantee problems with the choke without the detent. Put it back in and save yourself a lot of grief.

Just adjust your servo travel so the pushrod is unloaded at the closed and open points, not under stress. The detent ball and spring serve a purpose. Voice of experience.

TF

Tired Old Man

My Feedback: (1)

The instant the choke spring is removed from the carb on a Brison engine the warranty is void. Keeping the spring in place also maintains the correct spacing of the butterfly to the inside of the venturi. It could be the planes' demise in the making to have the butterfly jam up against the side of the venturi due to a missing spring.

My personal preference is to simply have a short meatl rod hanging from the choke lever that exits the bottom of the cowl. The manual method still works well for me. I understand that some have a need for another method of operationg a choke, though.

G-Pete

OK OK, convinced!

I take the ball back in…

Now I had a “good idea” once a year (hahaha) and you guys come and crushed it…



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G-Pete

G-Pete

rctom

There's no such thing as a good idea that cannot be crushed with sufficient piling on.

I am always a big proponent of using a choke servo, but on some side carb engines they are hard to implement. On a Brison 3.2 all I do is install a new choke arm made out of a 3/16" wheel collar and a 6-32 socket head screw about 3/4" long to hold the wheel collar on the choke shaft.

I just reach in through one of the cowl vents with a long screwdriver to flip the choke on or off.

TF

Tired Old Man

My Feedback: (1)

I thought the original idea was good, just leave the OEM parts in place. It's amazing what can be done with a carefully located bellcrank at times, tho.

G-Pete

Here some detailed pictures of the choke servo and connectors…


Happy landings[sm=thumbup.gif]
G-Pete