Throttle and rudder servo installs.

NOTE: the servo rails in the front of the model are too wide to accept a normal size servo. They are also a little to low and the bottom of the servo will hit the former at the rear of the landing gear plate. So in order to use these rails on just about any servo I tried I needed to put small blocks on top of the rails and also add a small extension to one side.

This again was a no big deal but a little disappointing to need the fix. In the end its not going to affect the flying and the weight added was maybe 1 gram. You will have to adjust the fix to your servo.

I also wanted to align it properly to give a straight shot to the throttle arm on the engine. So the engine needs to be bolted back in place. I used a long 12” 1/8” drill bit to align the pushrod exit in the firewall. See the photo below for the alignment.

I use a bolt through ball link like the heli guys use for the carb side of the throttle pushrod. Then on the servo side I use an EZ connector style adjuster. Actually the one I use is the Tettra. It has a little threaded nut that holds it onto the servo wheel. It’s also a low profile looking clean and neat. This type of adjustment is really good for a throttle linkage. Being that the Tettra has a locking nut on the bottom of it…there is no worry about it coming off the servo wheel. I use a little blue thread lock and never had one fail.

For pushrod material I use 0.047” music wire. It is stiff enough to handle the task yet can flex side to side with the movement of the Hyde mount. I really don’t like throttle cables and use this small music wire for various reasons. It needs very little support and it gives a positive control of the throttle arm. Use a 2-56 sold link on one side of the pushrod. The other one will pass through the Tettra adjuster. Sand the music wire with some 100 grit before you solder it. A little Silver solder is perfect for this mechanical connection.

While the engine is back on the model, mark the location for fuel line exits on the firewall. These don’t need to be drilled just yet…

The engine will have to be removed one more time before we fly it. So just mark the holes for the fuel lines. Keep the engine in the model for right now….Time to cut the air exits and muffler hole in the side of the cowling. For right now just get the throttle linkage aligned and ready to be finalized.