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The TruTrak ECO Autopilot really flies!

Ironflight

VAF Moderator / Line Boy
Mentor
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I know that lots of folks saw Tru Trak?s prototype demo of the low-cost ECO autopilot at Oshkosh a few months ago, and many looked forward to seeing it in action. I got a chance to fly it this weekend with Andrew in the Tru Trak RV-10, and I have to tell you folks ? this is revolutionary from both a cost and performance perspective. For $1,000, you get a two-axis autopilot that will hold heading, track a Nav source, and hold altitude ? the three things we all do with our autopilots about 95% of the time. For a VFR pilot, it is hard to think of anything else that you absolutely NEED. It has good control authority (I couldn?t tell much difference between it and Sorcerer installed in the airplane as well), and a unique feel ? because it flies with trim tabs, rather than manipulating the controls.

And then there is the Envelope Protection ? another cool feature that could very well make a huge contribution to GA safety.

I did a little write-up about it HERE, and there will be a full review in Kitplanes in an upcoming issue.

Paul
 
Wonderful time!

I had a wonderful weekend with you and "Ms Louise" :) thanks for your amazing hospitality! Also, thanks for letting me work on your new project. I don't get to do fun things like that much anymore!
 
Military 8

Paul,
Please define Military 8 as used in the article you posted. 30 minutes of web searches yielded no answers. My RV 8's are done at some multiple of the 30 degrees specified for Lazy 8's in the FAA PTS. Despite having a military background, I haven't heard of a Military 8 before.
Thanks for all your contributions to our community.
Cheers, David
RV-6A
 
Paul,
Please define Military 8 as used in the article you posted. 30 minutes of web searches yielded no answers. My RV 8's are done at some multiple of the 30 degrees specified for Lazy 8's in the FAA PTS. Despite having a military background, I haven't heard of a Military 8 before.
Thanks for all your contributions to our community.
Cheers, David
RV-6A

"Military 8" is just a not-so-lazy lazy 8 - somehitng less than a pair of wingovers, bt fairly steep.
 
Servos used?

As a long time R/C modeler, I would be really curious to know what servos they picked.
 
I learned how to do the military 8 from an F15 pilot this way. Pull nose up, freeze the stick and use rudder only to make the turn. Release backstick pressure once turn is initiated. Wing over and then use rudder only to level the wings. Pull back stick and do the same operation in the opposite direction. We called this a "canyon turn" as it really reduces the radius of the circles needed to form the not so lazy 8. Really a fun maneuver.
 
Thanks for providing those details, Andrew. I don't know anything about R/C servos but I do know I like my TruTrak Vizion 385.

I'm very curious to know how much cycle testing has been done on these servos in this application. As I'm sure you can guess, I'm concerned about a servo failure resulting in a high control force or, worse yet, a flapping A/P tab.

BTW, in a previous thread from the days when the ECO was first announced I mentioned something that I'll reiterate here. TruTrak is to be commended for bringing this high level of functionality and safety enhancement to the Experimental market at such an affordable price. Anybody who is building an airplane, even a basic VFR airplane, no longer has an excuse for going without an autopilot. Most Chief Financial Officers (typically a spouse) can be "sold" on the autopilot expenditure based solely on the argument of safety enhancements coming from the ECO's Envelope Protection feature.

Well done, TruTrak!
 
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testing

Thanks for the kind words. We really do appreciate it!

We are working on cycle testing. We stepped up to the larger servos from our original slightly smaller ones because of this. We found that the small ones didn't survive long enough for us. Hitec has told us that, how we are using the servos, they expect us to see about 250 hours out of the larger servo. We are working with them on ways to extend that, although when one can be replaced for less than a $100 hamburger it isn't that big of a deal.

As to the failure modes of the servos. Typically these servos don't run to a stop without being told to do so, although it's possible. This is why we don't advocate replacing any existing trim the aircraft has in place, especially in pitch. If a servo did happen to run away to a stop, then you can simply re-trim the aircraft and the forces are gone.

The failure mode we have experience more than anything else is the internal potentiometer or motor wearing. This causes the servo to "hunt" slightly, which you can certainly feel in the aircraft. The servo gets replaced / overhauled and away you go.

An autopilot master is ALWAYS a must. You must be able to remove power from both the control head and the servos should there be a malfunction.

We are currently looking at the servos as wear items, because they are so easy to replace and so low cost.

The entire idea behind Eco is to offer the safety of an autopilot to a segment of the market that hasn't been able to afford one before. Price, weight, and complexity are the leading reasons that autopilots are not installed. We aim to drastically lower all three with Eco.

thanks again!
 
Thanks for sharing this info, Andrew. If the service life is expected to be ~250 hours then servos should last something on the order of 5 years for most casual flyers (the target market for this autopilot). That's not a bad deal, especially if the most common failure modes produce warning signs like hunting, signs that won't be missed by the pilot.
 
Any idea when the ECO will be shipping?
My airport's owner was one of the first to place an early order for his RV4 (Andrew, you met John at Petit Jean a couple years ago). I'll be the one wiring it up for him... looking forward to seeing it in action.
 
So is the Eco pilot shipping?

Unfortunately, no. We're struggling to get suppliers to make some parts for us. It's pretty time consuming to hand make the kits and takes away from other duties. At last check, we're about 5 weeks out from having parts.
 
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