[tx_jayhawk]

All,

I am trying to finalize the last few wiring runs in the airplane, and I am curious how others have handled the strobes.

1) Depending on where you locate the power supply, you will have to "cross" the center tunnel to get the shielded wire from one of the wings to the power supply. Running wires through the the stock snap bushings right behind the main spar I believe has the potential to snag with the control column/pushrod assembly. Where have others crossed the tunnel with these wires, and how did you prevent inerference with the pushrod?

2) I have connectors for my wing wiring (I know there are differing opinions on that). Are most people passing the shield through a pin on the connector or allowing it to float on both ends of the mate? I know you are to float the light end and ground the power supply end, but I am curious on the observed performance with those using different wing mate connections.

Thanks,
Scott
7A Finishing

 

[N941WR]

Scott,

Initially I had planned on doing all the connections at the wing root but there just isn't room. So, I brought the wires inside the fuselage and connected them there.

My strobe pack is under the baggage compartment floor.


You are correct, this did require me to run the wires across the floor (via snap bushings) to either side and then forward. (I added another hole in the rear spar.)

The only push rod you have to avoid is the elevators. This was done buy gluing zip-tie pads to the center tunnel and tying the wires out of the way.

I used knife connectors, just because I had not used them anywhere else and wanted to try them. Cool but pricey.

As for the shielding on the strobe wires, cut it off out on the wing tip and continue the shielding all the way to the power supply. Here is another place where I used those knife connectors. Ground both the power supply and the shielding at the power supply. I tried running both the power supply ground and shield ground up to my central ground block and the strobes generated a good bit of noise. Grounding both at the power supply cut that out.

 

[Greg Arehart]

Scott,

I put my strobe power package behind the baggage bulkhead and then ran the wires out to the side of the fuse. Drilled small holes in both L and R sides of the bulkheads and passed the wires forward that way. Basically the wires are parallel to the rudder cables, but in a separate bushing near the bottom of the bulkhead. Never close to moving parts.

I did not put a connector in the wing root and plan to just snake the wire directly through the wing (within plastic pipe) to the strobes on the wingtips. No break in the shielding that way.

cheers,
greg

 

[Jim P]

Scott,

I located the single power pack under the baggage floor in the bay just to the right of the center tunnel and aft of the rear spar. For most wing wiring, I connected at the wing root. For the strobe wires, I ran through the fuselage and connnected directly to the powerpack. The left side transitions the tunnel just aft of the rear spar down below the elevator push-pull rod, with no interference. Yes, mine float at the light and are grounded at the powerpack end back to a common ground. I have zero strobe noise on the radios, which I'm really happy about.

Jim
(a whopping 11.5 hours airborne!)

 

[tx_jayhawk]

Thanks guys. It sounds like there should be sufficient clearance to cross the center tunnel. I may try Bill's idea of using knife edge connections for the shield wire at the root.

It sounds like some have gotten noise if running a ground from the power supply to the common ground, while others have not. I'll just have to experiment and see what I find as well.

Thanks,
Scott
7A Finishing

P.S. Jim, I am jealous...earlier this year I thought we were on pace to finish about the same time (based on your questions), but I must have fallen behind.

 

[Jim P]

That's interesting on the grounds. My p/s ground goes to a central ground in the center fuselage, which connects back to the singlepoint. All three strobe grounds are grounded back to the same point and have no radio noise. Interesting.

 

[N941WR]

That's interesting on the grounds. My p/s ground goes to a central ground in the center fuselage, which connects back to the singlepoint. All three strobe grounds are grounded back to the same point and have no radio noise. Interesting.

Jim,

This does not really surprise me very much. We have different planes w/ different strobes, different strobe power packs, different radios, different electrical equipment, different locations for the wire runs, different antennas, different wires leading to the antennas, etc.

I found the problem while still in the basement by simply turning on the strobes, radio, and intercom and then putting on my headsets. It was painfully clear there was a problem. After checking around it was suggested I ground both the power pack and strobe wire grounds locally, which I did and it solved my problem.