Left wing SV upgrade

[funflying]

I have finished the right wing lighting upgrade and used the string installed during construction to fish the new wires into place. Also the landing light access was a must.
Now I am on the left wing and the string is inside but access to the tip end does not exist. HOW HAVE OTHERS FISHED THE 2 NEW WIRES FOR THE LEFT WING??

 

[Bill_H]

You take off the tip light. Your string should have been secured to the wires attached to the tip light.

If not, you can do this - use one of the wires going to the tip light as a string to pull THREE new ones. One to replace the pulling wire, one for the split strobe-nav power, and one for the synch.

Now if you mean you have not installed the tip light yet, and built a wing without one, you have to cut that big hole in the wingtip - the one that gets covered by the fiberglass tip light holder. You reach the string through that hole.

 

[NASA515]

I wish I had read your post on three wires, Bill H., as only pulled two - not a big problem.

Question I have is - Is synching the two tip lites of value? My understanding is - they start out in synch and then slowly go out of synch. How slowly? They can be re-synch'd by switching them off and then on again.

These lites can be run synch'd or unsynch'd. Some airplanes do not allow synching. If unsynch'd, would't the extra flashes (three if you flash the landing lite) increase the chances for another pilot to see you?

Bob Bogash
N737G

 

[Mike S]

String is cheaper than wire

use one of the wires going to the tip light as a string to pull THREE new ones. One to replace the pulling wire, one for the split strobe-nav power, and one for the synch.

Or, you can use the existing wire to pull in a string, then the string pulls in the new wires and the original one back in, and while you are at it, pull in another string and leave it in place-----just in case you ever want to add yer another wire.

 

[funflying]

Thanks

The fiberglass tip is installed and the string out the root I can see traveling towards the tip in the inspection access (stall warning). I have a ground and lighting wire (B212) out of the tip mounting piece but no string. I am not sure how the string is secured. In the right wing it was tied to the end rib and like I mentioned accessable when removing the landing light.

My plan at this point is to use the wire in there, B212, attach a string and one new wire and pull it through. Then I will have a string at the tip. The second new wire I will attach to the string and B212 and pull those back to the root end.

What do you think?

 

[Bill_H]

I used fishing line not string. Those small bushings are full and you don't want string to become disconnected or jammed halfway. But the left wing is better than the right because it has one less wire. +1 for the stall but -2 for the landing light, net -1. Good luck!

You don't "have" to have synch. The lights work fine without it (obviously as the original installation did not use the synch wire.) It's marginally "neater."

 

[funflying]

VICTORY

Thank you all for the suggestions. I did use the existing wire to drag 2 wires and a string from the root to the tip. The tough part was making the last snap bushing at the tip. The angle was tough.

With the string I brought to the tip I returned the existing wire and it too was tough getting started through the snap bushing. Once on its way it went pretty smooth. Crimped on the connectors, installed the blue connector block, and re-did the plug end (tip). Left and right, wing & fuslage, done.

 

[DaveWelch]

re Victory

Congrats Patrick! I'll be doing to same soon. Is there any particular magic knot or fastening technique to attach the "pull String" and wires together? I'm thinking a reliable attachment that is also as slim as possible to avoid "catching" on the edges of holes.
Thanks for sharing your experience,
Dave

 

[NASA515]

I used heat shrink tubing. In my earlier (one wire short of the number needed) pull, we soldered wires together - staggered along some distance to ease the grommet transitions. Due to the grommet orientation (near flush on the inbd ends - sticking out on the outbd ends) and the last outboard grommet angle issues, it's preferable to pull from the root to the tip.

Also, allow about an inch of string (I used Boeing small diam. waxed wire bundle cord - very strong - slippery - small) to extend beyond the heat shrink in the direction of the pull. It will fold back on itself on the outside of the heat shrink making a secure attachment, instead of wanting to pull out the back of the heat shrink (a tip I learned from Tony T. - the Master himself.)

I finished both wings this week and tested all the lights with power on in the dark hangar - very sexy!

Bob Bogash
N737G

 

[funflying]

Similar

Bob always has some great ideas for sure!

I used some cotton string and ran it next to the wire for at least 6 inches. I used masking tape and wrapped it in a spiral to avoid friction and too much bulk.

At the tip end where it was tough to now curve the path to the final snap bushing I used a wire coming in from the tip to manipulate the wire/string and help it make the turn. It worked and I was so glad to see the blue masking tape appear.

There was a couple of times I was concerned I would pull the connection apart inside the wing...not good. But it all worked and looking back be patient and if it gets hard to pull back-off and "work it" a little.

 

[DaveWelch]

Thanks

Bob and Patrick,
Thanks a bunch! Sounds like two good ways to do it. Another thing I thought about was to use a Nail Knot. Used for attaching small diameter leader to large diameter fly casting line. Might be better for pulling a single wire than multiple wires though. Will experiment tommorrow and report.
Clear Skies,
Dave