Servo wire lube?

[Wazmo]

Has anyone tried lubricating servo extension wires in the wing? When I assemble the panels, the servo wires tend to bind up when I try to stuff the wires into the channels, making them bend and kink tightly. I thought that wire lube (used for pulling cable through conduit) might help, but I'm not sure about how long it lasts, or foam compatibility.

[dwells]

You got to loosen that up by bending in some relief else your servos are toast. I polished the music wire with Mother's Mag Polish and then go over with wax and buff them out. Try using some small plastic tubing to support the wire. You can use a high silicone grease to help if you have a crossover area that make friction where the wires touch.

[Wazmo]

Are you talking about pushrods? I meant the three-conductor electrical servo wires.

[T Tail]

:) skip the wax, just take a length of piano wire , guide it through the channel
and tape, tie, or glue the wires to the piano wire, and pull it through !

[lincoln]

If you're going to stuff wires, make sure there isn't any extra length that you don't need.

However, what I prefer is to use hot glue to hold mating connectors in the wing panels (for 3 piece wing) so that when you slide the wing panel on, it engages pretty much automatically. Of course this involves finding an appropriate connector and soldering, but that's no big deal. Use 0.100" spacing headers and mating connector of some kind, probably Molex.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=WM2723-ND
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=WM1576-ND

[Wazmo]

This isn't a first-time installation, it's a three piece wing with the aileron servos in the tips. Each time I assemble the wing at the field, I have to plug in the servo connector and stuff the wires and connectors into the wire channel. I like lincoln's idea, but I think it'll be a little tricky getting the connectors to line up. I assume you would use low-temp hot glue, since the channels are bare pink foam.

[dwells]

sorry Wasmo, i misunderstood...

[Ib Jensen]

I have installed connectors in wing tip panels and haven’t had to touched them in 5 years. I have used the .1 inch spacing pins and connectors which is the same type as is used in standard servo connectors. When I wanted something a little more rugged I made them out of surplus DB9 computer connectors cut down to 3 pins.

It is not difficult to get the connectors aligned. I install the female connector flush in the inboard panel. I have used both epoxy and hot melt for this, Hot melt has the advantage that if there is a problem you can get the connector out by heating the connector area with a covering hot air gun at the low power setting without damaging anything. It has the disadvantage that in hot weather, in the your car or sitting in the sun it can soften. (Do NOT use hot melt to hold your wing servos in place unless you live in a cold bleak climate. I did. I was lucky and checked the controls before launching. Dark wing in bright sunlight.)

Once the inboard connector is in place push the male pins through a barrier material such as plastic film. Insert the male connector into the socket with the barrier against the inner panel to prevent any adhesive (hot melt, epoxy, goop or chewing gum) from turning a 3 piece wing into a one piece wing. Add the adhesive to the outer panel and push it all together. When the adhesive has set, remove the barrier material and everything is perfectly aligned

Ib

[Wazmo]

Thanks, Ib Jensen. I'll have to give that a try.

For now, I figured out that if I gently tug on the servo extension where it exits the center of the wing, I can pull the tip connector back into the wire channel without kinking.

[rogerflies]

Pulling on the wire is a bad idea. You'll eventually weaken the joint between the wires and the pins, and something will break, short out, or otherwise ruin your day.

You can probably fashion some sort of strain relief to transfer the tension from the wire to the connector body without stressing the wire-to-pin connections.

Roger

[Wazmo]

Point taken, but I'm not really putting much strain at all on the connector. Just taking the slack out of the wire as I push the connector into the wire channel.