Trutrak Installation

I'm getting ready to install a TruTrak ADI II autopilot and servos. I had Stein build the harnesses for me, my main question is how most folks decided to run the harness to the pitch servo. The harness has the servo plugs already connected and it seems like the obvious choice is running it down the left side through the bulkheads, but I certainly don't feel as though drilling a hole in the bulkheads big enough for the plug to fit through is a good idea, nor do I want to remove the plug and rewire it after routing the harness. I don't think routing the harness along the center of the floorboard all the way back is a great idea either since there currently aren't any wires running through there and has no existing housing to shield the wires from our feet.

Thoughts/tips/advice?

truetrak installation

Hey Cole,

OK, take this from a builder's point of view......parts sometimes have to "fall off or fall apart" in order to be installed. I would remove/reinstall the connector in order to pull the wire through the bulkheads, whichever route your wire run takes (down the center push tube tunnel or down the outside skin.

Two possibilities for removing the connector. 1) use a pin extractor to remove the pins from the DB-9 housing.....or 2) cut the connector off, pull the wire, and re-install new pins/connector. Number 1) option sometimes doesn't work easily (at least in my experience, even with the correct pin extractor). Option 2) is easy, at least with the correct pins, DB-9 housing, and crimp tool. (BTW, I have a small stash of pins, the crimp tool, and...maybe the DB-9....have to check on that.)

As for running the wire down the tunnel (my preferred route) I used some tie wrap anchors pop riveted to the tunnel side ribs. The wire bundles for everything running down the tunnel are tie wrapped to these anchors....well out of the way of the push tube....no chance of moving and getting in the way of any moving parts.

PM me if you want to see some pictures, or need me to fly the crimp tool up your way .

Hey Steve, PM sent. I think it would all seem less daunting as well if I was doing this as part of the building process. The learning curve of figuring out how things work on a plane you didn't build is great experience though. Wish mine was laid out as cleanly as yours is!

The advantages of pre-made harnesses certainly diminish when you have to take them apart to actually run the wire. It's a pity that the typical connector is way too big to fit through any reasonable sized hole... but that's the way it is. And I don't know of any 9 pin connector that would.

blaplante said:

The advantages of pre-made harnesses certainly diminish when you have to take them apart to actually run the wire. It's a pity that the typical connector is way too big to fit through any reasonable sized hole... but that's the way it is. And I don't know of any 9 pin connector that would.

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Agreed, especially when my wiring skills/knowledge are seriously lacking. Of course, this is a great way to learn!

this also means the connector has to be reassembled with your head stuck in the tailcone, under the seats, up a wing access hole, etc. Not on a workbench.

A partial explanation why avionics installs aren't cheap. I can't do more than a couple hours of the stuff before my back is saying no more!

Holes in centre area

One important piece of advice, if you're not already aware, is to be very careful about drilling any holes through the main wing spar shear web for the wires to pass through. Vans permit a second hole in a location that mirrors the hole for the manual elevator trim cable and that's about it!
Depending on the diameter of the cable bundle, it may also be possible to feed it beneath the top longeron; normally there would be a small gap around 0.25 x 0.5 inch under the side deck at the top of F604 (spar bulkhead). Though that space may be already used for the static line?

M5fly said:

I had Stein build the harnesses for me, my main question is how most folks decided to run the harness to the pitch servo.

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By far best to run down center tunnel under floor boards. Under floor to keep it from being in the way or damaged, center because only place to get through front spar. Just keep it tied off away from the elevator push tube. As mentioned in previous post, do not just willy nilly drill holes through spar. I found there is plenty of room for the autopilot bundle to fit with all the other wires through the manual trim hole and it’s mirror.

blaplante said:

this also means the connector has to be reassembled with your head stuck in the tailcone, under the seats, up a wing access hole, etc. Not on a workbench.

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Choose wisely the connector end you cut off to minimize the pain of redoing the connector. I would cut the connect off at the servo as that side maybe easier to access to put on the new connector. Depends on how much extra length Stein made the harness to give you some service loop slack.

Just part of the process, and really easy.

plehrke said:

By far best to run down center tunnel under floor boards. Under floor to keep it from being in the way or damaged, center because only place to get through front spar. Just keep it tied off away from the elevator push tube. As mentioned in previous post, do not just willy nilly drill holes through spar. I found there is plenty of room for the autopilot bundle to fit with all the other wires through the manual trim hole and it’s mirror.



Choose wisely the connector end you cut off to minimize the pain of redoing the connector. I would cut the connect off at the servo as that side maybe easier to access to put on the new connector. Depends on how much extra length Stein made the harness to give you some service loop slack.

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+1

I had this exact situation when building. I had no skills and didn't know what I didn't know. In the end, cutting off the connector and routing the wire where it best routed was the easy solution. This was my virgin moment, my first real termination exercise. YMMV, but my time and fear wasted more life juice than just doing the task. The wiring became so much easier after this first harness.

plehrke said:

By far best to run down center tunnel under floor boards. Under floor to keep it from being in the way or damaged, center because only place to get through front spar. Just keep it tied off away from the elevator push tube. As mentioned in previous post, do not just willy nilly drill holes through spar. I found there is plenty of room for the autopilot bundle to fit with all the other wires through the manual trim hole and it’s mirror.



Choose wisely the connector end you cut off to minimize the pain of redoing the connector. I would cut the connect off at the servo as that side maybe easier to access to put on the new connector. Depends on how much extra length Stein made the harness to give you some service loop slack.

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My concern with being able to run down the center tunnel is 1. I don't have any way to enclose the harness in the footwell 2. I have manual trim so would definitely have to drill an additional hole and 3. I'll have to work around the battery which is mounted against the firewall in the center run (PC680 mounted length-wise).

Is it worth fabricating a cover that encloses the space between between the floor stiffeners so I can run the wires there as opposed to feeding it underneath the longeron on the left side? IIRC, right now the static line, coax, and wires for the tail beacon run through a couple lightening holes above the rudder cable on the left side. Wires for my headset jacks run through a lightening hole in the same area of the right side.

I'll get some pictures this weekend and post, that may help give the best advice on where to run it. I did already plan on removing the servo connector as the easiest route, so on board there. Thanks for all the great responses so far!

Cole, sorry I didn't; see this thread earlier, but there is a lot of good discussion and ideas. I don't; recall what your interior is like, but if you have side panels, they can hide a lot!

I have done more additions and deletions to our RV-6 over the years than I can remember, and generally speaking, it isn’t that hard to run stuff down the sides. Removing the connector at the end of a pre made cable is really pretty simple - far easier than coming up with a master plan to get the connector though all the places it needs to go. Tools are available!

Paul

Ironflight said:

Cole, sorry I didn't; see this thread earlier, but there is a lot of good discussion and ideas. I don't; recall what your interior is like, but if you have side panels, they can hide a lot!

I have done more additions and deletions to our RV-6 over the years than I can remember, and generally speaking, it isn’t that hard to run stuff down the sides. Removing the connector at the end of a pre made cable is really pretty simple - far easier than coming up with a master plan to get the connector though all the places it needs to go. Tools are available!

Paul

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Paul, thanks for the words of encouragement. As someone mentioned above, most of my fear is rooted in having very little experience doing it and not wanting to screw anything up. The longer I own my RV, the more I seem to find out how simple every part of it really is - just takes a little knowledge or supervision to figure it out the first time.