Adding Dynon servos to F1 Rocket?

[GyroF-16]

Anyone here added Dynon autopilot servos to a Rocket?
My concern is that “older” RV4s need a different elevator bellcrank retrofitted to accommodate the servo (per Dynon). My Rocket has a RV-4 tail made before 2005, so I think this applies.
Is there a better way to install the pitch servo?

 

[Scott Hersha]

Here’s how I did mine on my RV4. The Rocket might be about the same. Removing the existing bell crank bracket and trying to rivet the Dynon servo bracket in that narrow space looked almost impossible. My solution is two pieces of 1/8” aluminum bar stock bolted to the exist bracket, using a longer bell crank bolt, two short bolts forward that don’t interfere with the bell crank, and the two servo attach bolts with spacers. It’s very solid and works well.

 

[GyroF-16]

Here’s how I did mine on my RV4. The Rocket might be about the same. Removing the existing bell crank bracket and trying to rivet the Dynon servo bracket in that narrow space looked almost impossible. My solution is two pieces of 1/8” aluminum bar stock bolted to the exist bracket, using a longer bell crank bolt, two short bolts forward that don’t interfere with the bell crank, and the two servo attach bolts with spacers. It’s very solid and works well.

Essentially identical structure to my Rocket back there…
That’s great, Thanks.

 

[GyroF-16]

Here’s how I did mine on my RV4. The Rocket might be about the same. Removing the existing bell crank bracket and trying to rivet the Dynon servo bracket in that narrow space looked almost impossible. My solution is two pieces of 1/8” aluminum bar stock bolted to the exist bracket, using a longer bell crank bolt, two short bolts forward that don’t interfere with the bell crank, and the two servo attach bolts with spacers. It’s very solid and works well.

That looks like the servo is mounted further aft than the standard brackets would have it. Did you need a longer servo arm, and/or a longer pushrod to reach the bellcrank?

 

[CCG]

Here's the brackets I fabricated from angle and sheet to my the Dynon servo in my F1. No change needed for the bellcrank other than a hole.

 

[Ironflight]

That looks like the servo is mounted further aft than the standard brackets would have it. Did you need a longer servo arm, and/or a longer pushrod to reach the bellcrank?

Especially with a Harmon (but also true of most older designs) you’ll be customizing the installation brackets and pushrod length. Its all easy fabrication, so don’t worry about modifying (or throwing away) the parts you get in a kit and making what you need. I doubt Ive used a “stock” servo installation kit on any of our RV-type planes (-3, -6, -8, F1….).

 

[Scott Hersha]

That looks like the servo is mounted further aft than the standard brackets would have it. Did you need a longer servo arm, and/or a longer pushrod to reach the bellcrank?

I didn’t buy the Dynon servo bracket kit. I just fabricated what you see in the pic, including the pushrod so it’s probably longer than the stock kit part. Shouldn’t make any difference as long as you are getting proper throw and not coming close to going over center on either end.

I also fabricated a bracket for my roll servo in my RV4. The Rocket is probably different…..

 

[GyroF-16]

I didn’t buy the Dynon servo bracket kit. I just fabricated what you see in the pic, including the pushrod so it’s probably longer than the stock kit part. Shouldn’t make any difference as long as you are getting proper throw and not coming close to going over center on either end.

I also fabricated a bracket for my roll servo in my RV4. The Rocket is probably different…..

That actually looks similar/near identical to my F1 Rocket in that area as well. Thanks! Those photos will really help in planning an installation in my plane.

 

[GyroF-16]

Here's the brackets I fabricated from angle and sheet to my the Dynon servo in my F1. No change needed for the bellcrank other than a hole.

Thank you for posting that. The more examples I see, the easier it’ll be to decide on a method for my plane.
Did you use any parts from the Dynon bracket kit, or roll your own?

 

[CCG]

Thank you for posting that. The more examples I see, the easier it’ll be to decide on a method for my plane.
Did you use any parts from the Dynon bracket kit, or roll your own?

I used some parts from the Dynon universal kit. Bearings, threaded rod, etc. The mounting brackets were from misc materials I had on hand.