Autopilot Choices and Results

[Mark Dickens]

I definitely want an autopilot for my Companion. Who's using what and are you satisfied with its performance. Since I have the Dynon Skyview suite in my RV-8, I was planning to do the same thing in the Bearhawk, but wanted to hear from those who have been there and done that. What do you have and how do you like it?

[500AGL]

I’m a Garmin guy and love the GFC500 although I’ve not flown it in a Bearhawk I expect the same experience as other aircraft.
Since you are familiar with Dynon, I’d recommend sticking with familiarity unless there’s a good reason not to.

If things turn south one falls back to what’s ingrained in them through training or time.

pb

[Ed.Meyer]

I fly a Patrol with Dynon Skyview and two axis autopilot. I use it routinely on long cross country flights. It seems like it is holding altitude better since the version 16 firmware update and they said they had made autopilot algorithm improvements. I notice the adverse yaw with the ailerons and I usually help it some with the rudder.

[jaredyates]

Here is my complaint about the autopilot:

https://bearhawk.tips/3991

And Russ Erb's counterpoint:

https://bearhawk.tips/4172

[Utah-Jay]

Here is my complaint about the autopilot:

https://bearhawk.tips/3991

And Russ Erb's counterpoint:
https://bearhawk.tips/4172

Can’t access the link as it is password protected

[jaredyates]

Can’t access the link as it is password protected

Tldr;
I didn't feel like Dynon was willing to support their system for three axis, and I had high expectations for functionality. I couldn't get it to function well enough to justify the cost and weight. Russ uses only two axes, and does the feet part manually. He finds it is still worthwhile, even though it isn't perfect.
Maybe in the years since then, Dynon has decided to publish what the setup variables do. I never could get them to tell me, after a year of asking.

[zkelley2]

Ya, I can't imagine it being all that useful in roll considering the adverse yaw. That and to me, an autopilot is largely for workload reduction in the IFR environment, and the uncoordinated turns it'll make while IMC isn't something I want to experience.

[schu]

I have a full 3 axis garmin setup that I expect to work fine. I'll be using electric trim and let the AP trim for me so that I don't need massive pitch servo, and so that when I cancel the AP, it doesn't hand me a handful.

[swpilot3]

I decided to try the 3 axis dynon in my BH. It doesn't compare to an autopilot in a transport category aircraft, but I'm actually quite impressed for a little airplane autopilot. It does just about as good a job following the flight director in coordinated flight as I can if I'm paying careful attention to flying the instruments. It does way better than I do if I'm trying to sight see while flying! :-). It coordinates the turns very well.

Most of the default values are for an RV, so it did take a fair amount of fine tuning for the BH. Dynon itself doesn't say much about calibrating the yaw in the manual. However, I found a post online from a Dynon tech that explained it. Here it is: https://forum.flydynon.com/threads/y...-for-rv10.495/.

FWIW, I'm glad I installed it.

[Mark Dickens]

Any chance you have photos of your yam damper installation?

[schu]

In a bearhawk there is really only two ways to make it work.... either mount the servo behind the rear bulkhead with some pulleys that run a cable to the sides then clamps onto existing rudder cables or mount the servo on the firewall with some pulleys that run a cable from the back side of the rudder pedals up to a servo in the middle.

Either way, you are making a loop of your rudder system. In the case of the rear mount a short loop with extensions up the pedals, or in the case of the found mount, the entire system is a loop.

I did the front mount because I want the weight up front, and because I have extended baggage that would put the servo really far back.

[Mark Dickens]

I fly quite a bit of IFR in my RV-8 which has the full Skyview suite. I've owned two planes with G1000s and there's no question that the GFC-700 in those planes was an amazing autopilot. I didn't expect GFC-700 performance out of an experimental avionics suite (and it doesn't cost anywhere near the G1000 costs either). My main desire for the autopilot in this plane is to allow me to relax on long cross countries in VFR or light IFR conditions. I'm not building this to shoot approaches to minimums, but I am equipping it to do that, and while I hadn't planned to add the yam damper, I think I'll add it. I'm not used to lots of adverse yaw and it sounds like the yam damper might be a good investment

[tailwind]

The yaw damper will be a welcome addition in the Bearhawk. I had a two axis garmin autopilot in my Bearhawk. It worked well but not near as good as the garmin 500 in my new plane. My advice is to get pitch, pitch trim, role and yaw. You will not be disappointed. I just returned from an 18 hr round trip flight. The autopilot takes all the work out of the flight without taking away the fun.

[svyolo]

A yaw damper on any aircraft needs to be "tuned". Actually all three axis need to be tuned. But pitch and yaw are easier to get close. Based on what I read before, the ability to tune the Dynon for yaw is poorly documented. Probably the guys building it don't have the expertise to tune an autopilot, or to come up with a set of procedures for a EAB builder to do it. I believe the functionality is there. Unfortunately for the most users, this results in poor 3 axis control.

[Rollie]

I have the Garmin G3X and two Garmin servos controlled by the G3X. Setting up the gain on the AP is pretty straight forward and is laid out in detail in the G3X installation manual. After my initial setup mine was hunting excessively for altitude in rough air and I suspected the gain needed to be turned up to make it more aggressive so it would correct sooner but by following the manual I found that I needed to turn down the gain to correct it. It took about 10 minutes of looking up and reading the instructions and maybe 10-15 minutes in flight to set it all up and now it holds altitude like it should. I fly it IFR and even when getting bumped around pretty good I don't get more than 30 feet off altitude (and usually much less than that) so I'm happy.

A yaw damper would be nice. I fly with my feet on the pedals and have to keep it in trim in turns. I have an idea for a set up that I think would work but it isn't enough of an issue that I'm likely to do anything about it in the near future. Maybe when the plane needs new fabric in 20-30 years. My idea is to install a bar horizontally in the tail the pivots in the center that the rudder cables would mount to, then have a rod go from that to one side of the rudder, eliminating the cables from the bar back to the rudder and connect the servo to that bar. Pretty simple but would require welding in a strong mounting point for that bar to pivot on, of course with a bushing or bearing or something.

[spinningwrench]

I am using a Garmin G3X panel in my Patrol and have finished the installation of the servos for roll and pitch and now working on the final yaw axis installation. Yaw is probably the more difficult installation but Garmin makes a nice capstan drive for their servos which makes attaching to the rudder cables fairly straightforward. I'll post pictures when done.