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jflyboy 05-18-2022 01:24 PM

Adding AP
How bad is adding an AutoPilot to existing airframe? RV-7a.

What AutoPilot is best bang for buck? Trio? Dynon? Trutrack?

Thanks, I’m right of first refusal on a low time RV-7a that has early dynon d-100 & d-180

Edit: I have decided to pass on the plane, also it had 2x D10 units not the D100/180 as initially thought. Regardless appreciate the responses always amazed how quickly y'all help!

pa38112 05-18-2022 01:31 PM

The difficulty depends on your skill-set. I did not find it difficult, but it will take some time.

TrueTrack is the best bang for the buck, and is an awesome autopilot. But it really depends on what avionics the plane already has that you will be connecting to...

bruceh 05-18-2022 02:24 PM

It isn't hard to add the servos. The pitch servo lives back in the fuselage behind the baggage bulkhead. The roll servo is mounted in the right wing. Roll servo is a little tighter space to work in, but very doable.
Running the AP wires through the wing might be the hardest part. I would consider updating the Dynons to Skyview. You can find pretty good deals on used equipment here. Dynon sells all of the mounting hardware to make it a bolt on addition.

BobTurner 05-18-2022 02:37 PM

I vote for the Trio Pro. If you have electric pitch trim the Trio will even handle that. Their servos use a slip clutch rather than the trouble prone shear screw in the TT. And when its disconnected its really disconnected, no stepper motor in the loop. TT is now part of a larger company, future a bit uncertain(?). Only real issue is panel space: TT 2 1/4 hole, Trio 3 1/8 hole (or rack mount). If you upgrade your panel a directly EFIS driven autopilot will be less expensive as all the attitude info is already in the efis box. But of course you lose redundancy. A lot depends on your anticipated use, from just vfr cruise flight to ifr approaches.

wirejock 05-18-2022 04:47 PM

No sweat. There's gotta be a builder nearby. Worst part is routing wire but that's an opportunity to learn. Wing servo is tight space but I've had mine in an out a couple times. Consider integrating trim servos. Most systems auto-trim now.

drill_and_buck 05-19-2022 06:55 AM

If budget is a consideration you could buy two Dynon servos and connect them to the D-180.

The bigger question is what is going to drive the AP? You will need a GPS enabled moving map for flight plans, etc. Ideally one that will display weather and traffic. Budget minded options to consider would be the Garmin Area 760 or Ifly 740. There are also older GPS models available on the used market that could also easily work.

All it takes is time, money and effort!

g3xpert 05-19-2022 11:34 AM

G5 Autopilot
You can install a simple G5 based autopilot that will fly this airframe very well, with only a few basic components (listed below).

We sell servo mounts specifically for the RV7, that are around $95 each. The GSA 28 servos can connect to your trim motor to drive autotrim as well, so when you disconnect the autopilot, the plane will be in trim.
  • 1 x G5 ($1340.00)
  • 2 x GSA 28's ($800.00 each)
  • 1 x GMC 507 ($1238.00)

With the above equipment list, you would have the ability to engage the autopilot to hold a selected altitude or indicated airspeed, command vertical speed climbs and descents, follow a GPS track, as well as both vertical and lateral navigation information from a serial based navigator like an SL30 or Aera 660.

Heading mode can be enabled by including a GMU 11 magnetometer ($350.00).

All of the G5 autopilot components are connected through a single two conductor databus that is daisy chained from one component to the next.

We are always available via phone or email should questions come up!



Southern Pete 05-20-2022 06:45 AM

I would also suggest Garmin. Their controller is by far the best in terms of the interface to make the aircraft do what you want and their control algorithms are very good. I had a Trutrak (now BK I believe) in an old aeroplane, it was pretty good but Garmin is better and is easier to interface to other equipment if that is required in the future.
Installation in an RV is straight forward as RV specific servo mounts are available. The most challenging aspect is routing the wires through the spar - in a 7 there should be some holes beside the elevator rod for just that purpose.

PaulvS 05-20-2022 07:56 AM

OP has asked for "best bang for the buck", which would be to add two Dynon servos to the D100/D180 system that is already in the RV-7A. If in future the system is replaced with Skyview then the servos can be retained.
There are currently supply constraints with some brands and models of avionics, so that is another thing to consider.

rv8ch 05-20-2022 09:17 AM

All the servos install pretty much the same, and it's not that hard. It's about the same work as if it was a new install - I installed my roll servo through the wing inspection panel and it was no problem. Just need a good, comfortable place to lay under the wing, and a helper to hand you cool drinks and tools that you forgot.

Same with pitch servo - this can be installed in a day if you are prepared - but I'd recommend finding an experienced builder to help, since you'll need to drill out some rivets.

The Dynon and Garmin servo install kits and instructions are great - and work with other servos like my GRT servos.

BTW, I love my AP - I use it all the time, not because I'm a slacker (which I am) but to increase safety. The AP certainly flies straight and level far better than I can. I mainly use it in alt hold and heading mode.

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