View Full Version : Dynon Autopilot trim problem

03-18-2017, 03:07 PM
I just upgraded my panel to dual Skyview HDX displays (7" & 10") with the knob panel and the Autopilot control Panel. On my first flight with this new setup I did the ground checks of the trim and all seemed to work ok, but when I flew my first flight, on liftoff I encountered full nose up trim and trim not responding to the electric trim inputs. As you might guess I had my hands full horsing the beast around the traffic pattern to get it on the ground.
Back to the avionics shop I went in and described the problem. After checking everything out and ground checking the trim operation I attempted another takeoff and encountered the same problem- full up trim and no response from trim switch in either direction. Once back on the ground I taxied back to the avionics shop-AGAIN, shut down where we once again checked the trim, where it performed flawlessly.
We then decided to check the operation of the trim with the engine running, with one person standing outside to observe the movement while I activated the trim. The plan was for me to activate the trim in both directions, while the outside observer would give me a thumbs up or down to indicate the direction of movement. Initially the trim worked in one direction (up), but would not respond in the opposite direction. Eventually it quit responding altogether.
I returned the AP Controll panel to Dynon for repair, and today checked its operation before and after start before flight, and low and behold, the Trim worked great with the engine shut down, but once again I encountered the same problem as before with the engine running. I found that the way to get around this is to bypass the AP Panel with the trim, but then I do not have the Autotrim function or trim position indication.
My question is whether anyone else has experienced a similar problem, and if so how did they remedy the problem. Could this be a incorrect setting in skyview or do I have a defective AP Panel.
Frustrated in Jacksonville

03-18-2017, 06:22 PM
You might try viewing the Dynon forums for answers. I would definitely give dynon a call before further flight. You also might try flying the autopilot in the simplified mode and see if you get the same result. Good luck.

03-19-2017, 06:24 AM
I would go see Jesse at saint Avaition. Even if I had to disconnect the auto pilot to go there. He will have it fixed before you get back from lunch.

BCP Boys
03-19-2017, 06:53 AM
Jesse sells and installs a lot of Dynon. If it's a Dynon problem he will know fairly quick. If you are in JAX then it's nothing to hop down to his shop and have him take a look at it. It sounds like you are already working / paying someone anyway, why not work with someone who has a lot of experience with Dynon?

Also, recommend turning off your Autopilot if you have wired a switch to it or pull the breaker to it, get to altitude before testing.

03-19-2017, 06:55 AM
I had an install hat did the same thing. I replaced the AP Panel and that fixed it. Try hooking it up to Motor 2 and see if it works better. Make sure you have the trim position installed, calibrated and displaying so you don't take off again without having the trim where you want it.

In my experience, electronics fail either when they are brand new, or very old. I have an AP panel in stock. We could pop it in and test it if need be.

03-19-2017, 07:44 AM
Thanks for the replies guys. I will try and get it to Jesse ASAP. What would be a good day Jesse? Would tomorrow (Mon) work?

03-22-2017, 07:19 PM
I flew my RV7 down to Jesse at Saint Aviation today. What a pleasant and productive experience. This man knows Dynon and it was apparent to me that he is very knowledgeable about Van's Aircraft and Dynon avionics. If only I had taken my aircraft to him initially for the Panel install, I could have avoided all the headaches. Jesse quickly identified and corrected two or three problems with the install the previous shop had made. You can bet that I will be a return customer in the future. Thanks Jesse. Keep up the good work, and God Bless.
David Johnston

03-23-2017, 02:40 PM
Did they setup the trim motors in the trim set up menu on the HDX ?

03-25-2017, 05:35 AM
The problem with my trim was due to the shop that did the initial Skyview install not following the install manual. My aircraft had a trim relay which should have been removed when the SV AP Panel was installed. My understanding is that the relay within the SV AP Panel was fighting the second relay. Jesse also removed an unneeded trim indicator, that was apparently installed by the original builder of this aircraft.. The Ray Allen trim motor already has an indicator built into it.
Jesse is very knowledgeable, and a great guy to boot. You can bet that I will be using him from now on.