Wire routing and fuselage standoff

[Mesteve]

I am about to run my first wire, the trim motor, and cannot find anything about the best route to take. I have seen discussion about how/where to run wires through the cockpit, but not the aft half of the fuselage. As of now I am planning on mounting the ADAHRS on the LSA-style cross member location and the VHF antenna in the VS.

Also, I am of the mindset of avoiding just throwing a zip tie on it and calling it good, so what is the preferred method for a single wire? 2 Adel clamps seems overkill and unnecessary weight...

[Dave S]

Mesteve,

A couple things I have seen people use - hockeystick tape (comes in black and white) around the tube to protect the tube from the zip tie (and keep it from sliding). If a person wants to use aircraft stuff - the red silicon self fusing tape around a tube works well for the same purpose. Cushion clamps do work but I agree with your comment on weight, cost and unnecessary complexity.

[efwd]

My DAR doesn't like to see the wire touch the airframe tubing. I used silicone tape, a wire tie around the tube then another wire tie around the wire and then secured to the first wire tie. I suppose the wax string is another option. Honestly, I am not an Eagle Scout so I couldn't figure out what knot to use that wouldn't come loose. All my square knots came undone so I rely on wire ties.

[airlina]

Another consideration that I learned the hard way is not to do your final bundling and securing until you are 100 % sure that you have run ALL your wires and are ready for cover. I can't tell you how many times I had to add another wire to an already secured bundle and had to unsecure the bundle add the wire and redo. To avoid this , you can use thin velcro straps available at lowes or home depot that can be used as a temporary security system until you are done , then use your final wraps in the end precover. I learned how to use lace cord and like it better than zip ties , although sometimes the zips are inevitable as you need enough room for hands to be able to tie knots with the lace cord. Bruce N199CL

[DesertFox4]

I did something a little different that Murle Williams has done on several of his builds over the years. I used that very thin walled black sprinkler tubing and ran a length of it from just behind the seats back through the fuselage to just behind the trim actuator and curved it up towards the horizontal stabilizer. Safety wired it several places to the airframe before covering the fuselage. Gives a nice smooth conduit to run the trim actuator wires, com antenna cable ( my com antenna is mounted in the vertical stabilizer) and tail light wires. Makes adding or subtracting wires very easy. It’s very light weight. Did the same in my model 4 build. Room for several pairs of wires if needed in the future although I can’t think what else will ever need to go back to the tail.

[rv9ralph]

One more consideration. When anchoring the wires, do not use a frame member that will be touching or near the fabric covering... use interior tubes.

Also, If I can explain clearly. To stand the wire off from the frame/tube you can use a wire tie and a 1/4 to 3/8 length of tubing. By passing the wire tie through the tubing, around the tube/frame back around the wire and close the wire tie. As a second option on the same method, after passing a wire tire around the wire and frame/tube, before lighting use another wire tie at 90 degrees to the first and close it around the first wire tie using it as a spacer between the frame and wire.

I hope you can visualize my explanation and I hope this helps.

Ralph

[Mesteve]

One more consideration. When anchoring the wires, do not use a frame member that will be touching or near the fabric covering... use interior tubes...Ralph

It does make sense, but only because I've seen it done before. Thanks

[jiott]

I did the same as DF4 using the lightweight sprinkler tubing, 3/4", to run wires and also my pitot static tubing. It is easy to slit a portion of the tubing to exit wires at various places.

[efwd]

yeh Ralph, I thought your description was great. I have examples of both throughout my build. I would have like to use the sprinkler hose idea.

[David47]

This is what Ralph was referring to.

[rv9ralph]

Yes. But I would cut the tails of the cable ties as close as you can to the ratchet head. Those corners can do damage to your forearms when reaching for something else.
(The voice of experience.)

Ralph

[PapuaPilot]

You can do a similar thing by using 2 cable ties, one becomes the stand-off.

Like Ralph said . . . do yourself a favor and cutoff the tails. I have made cutoff tool with some cheap HF diagonal cutters. You can do this by grinding off the back side of the cutter until it is flush, like a razor edge.

[efwd]

Yeh, from where you stand now, with the long "toe nails" on your wire ties, you can just use the large toe nail clippers that look like side cutters. I concur with the "little knives everyplace" analogy as you have now.

[redbowen]

You can get a set of flush cut dikes, basically the same thing, at Harbor freight.


You can do a similar thing by using 2 cable ties, one becomes the stand-off.

Like Ralph said . . . do yourself a favor and cutoff the tails. I have made cutoff tool with some cheap HF diagonal cutters. You can do this by grinding off the back side of the cutter until it is flush, like a razor edge.