Snap bushings in wing ribs of RV-14

I am wondering as to the latest opinion concerning the snap bushings in the wing ribs (Ref 14-04) I am aware of the "Master list of common errors" posting by Debovsky questioning the size of the bushings (thanks!). But I don't know what the final verdict is. I am at the point of drilling the rib holes and I don't want to try to shrink the holes if they are drilled out too much. Also, if I change the whole size, I will need to source out a larger snap bushing.

My crystal ball cracked last week so has anyone gotten a revelation or maybe figured it out for sure?

Gahannaflyer said:

I am wondering as to the latest opinion concerning the snap bushings in the wing ribs (Ref 14-04) I am aware of the "Master list of common errors" posting by Debovsky questioning the size of the bushings (thanks!). But I don't know what the final verdict is. I am at the point of drilling the rib holes and I don't want to try to shrink the holes if they are drilled out too much. Also, if I change the whole size, I will need to source out a larger snap bushing.

My crystal ball cracked last week so has anyone gotten a revelation or maybe figured it out for sure?

Click to expand...

I am not aware of the reference you quoted on oversized holes for snap bushings, but . . . I have a 7 QB and all the holes on the ribs along (behind) the spar and through the spar are slightly oversized. Enough that the bushings began coming loose with the sharp curvature of the wires going through and allowing the wires to contact the metal. My home-brewed solution was to add a dollop of E9000 or shoe goo to the perimeter on the non flange side after installed. It firmed them up nicely. Even it it does not stick it makes the piece too big to easily slip back through the hole. I don't know how the oversized holes came into existence. Maybe there are more elegant and professional solutions. I am listening . .

Was your wing kit shipped prior to 9/25/13?

If not, then your plans should have all of the updates done at that time (some of which included changes/corrections related to snap bushings.
You can compare your plans the latest up date issued on that date by going HERE

My previous plans were pre updates, but I have since downloaded the latest. I guess I was concerned that the latest instructions reflected the issue of correct bushing sizes. Obviously trying to fix the bushing issue down the road would be difficult at best. The "Master list of common errors" did not mention if the bushing trist was addressed with the new updates.

Thanks

Snap bushings

My kit (#39) was pre-update. I changed to the post-update snap bushings before installing the the bottom skins. I purchased the snap bushings from Vans for a few dollars. I also purchased an assortment box of snap bushings from Stein Air. I figure I will need it at some point.

I understand changing out snap bushings after the wings are complete would be impossible. Van's has supplied all the wing harness with the wings and they easily fit into the first version print snap bushings. What are the revisions for?
The only way I see you can add wires to the wings after the fact is if you had conduit to slide the wires thru.

If you are concerned with the hole size, you can always drill a few different holes in some scrap material and see which size you like best.

Fitting the snap bushings in place and holding nicely is not the problem. I am concerned that at some later date I might want some other gadget in the wing cavety. Maybe not enough room for more wires. I am contemplating putting an aluminum conduit in, and fishing more wires as needed.

Am I off base here?

Instead of putting in a conduit, do what I did after a suggestion from my tech counselor on my first plane. Just run some additional wires now with extra length outboard and to pins in a connector inboard. Turns out I used my extra wire when I retrofitted to LED lights and needed a sync wire.

I would suggest a 16-18 ga wire and a 20-22 ga wire in each wing. It will weigh less than the conduit and you can use them if you ever need them in the future. Worked great for me and I plan on doing the same in this plane.

We use conduit, but running some extra wires is a good idea also. In the -10 you can reach all of the ribs from the inspection panels, so wires can be added, but it would be a food idea to upsize the holes and out in bigger bushings to start with if you plan on going this route.

Gahannaflyer said:

Fitting the snap bushings in place and holding nicely is not the problem. I am concerned that at some later date I might want some other gadget in the wing cavety. Maybe not enough room for more wires. I am contemplating putting an aluminum conduit in, and fishing more wires as needed.

Am I off base here?

Click to expand...

You don't want aluminum. That would add too much weight at the size you will need. Don't use PVC either.

I used the following conduit that Van's sells.

http://www.vansaircraft.com/cgi-bin...18-6&browse=electrical&product=wiring-conduit

Just open up the bushing holes a little larger to accommodate the conduit. It's also pretty easier to cut holes along the way to accommodate for things like your pitot heater wire and stall warning that may be at different locations in the wing.

As long as you leave a pull string in the conduit, you can add things easily at a later date. I just pulled some tubing for my AOA well after I was flying. All I had to do is just take the wing tip off and connect the tubing to the pull string.

You can get similar products at Home Depot, lowes, or you favorite electrical supply house. It's called interduct and used for keeping wiring separate in large conduits. Just make sure it's plenum rated. You need to be concern about what fumes and gases are emitted, should it ever catch on fire.

Bob Leffler
Thanks.
A question.
Is it plenum rated "interduct" or "innerduct"?
I just looked at the internet to find it and found innerduct but not interduct. Not trying to be smart, just want to make sure I am onto the correct stuff.
John

Conduit

My guess is the purpose of the conduit would be to make adding future wires easier. The 14 has three access panels on the bottom of each wing. With the tip off and the panels open, I can reach all the wiring from tip to root. I'm not certain the conduit is really necessary, but that is just an opinion.

rjtjrt said:

Bob Leffler
Thanks.
A question.
Is it plenum rated "interduct" or "innerduct"?
I just looked at the internet to find it and found innerduct but not interduct. Not trying to be smart, just want to make sure I am onto the correct stuff.
John

Click to expand...

It's inner duct..... A combination of iPad autocorrect and the time of day.

The conduit from Van's is pretty thin, light weight, and flexible. Some inner duct can be pretty thick and rigid.

M McGraw said:

My guess is the purpose of the conduit would be to make adding future wires easier. The 14 has three access panels on the bottom of each wing. With the tip off and the panels open, I can reach all the wiring from tip to root. I'm not certain the conduit is really necessary, but that is just an opinion.

Click to expand...

You are correct, the RV-10 is exactly the same. While possible, doesn't necessarily mean easily and pain free. But that is a more subjective opinion based on what each of us are willing to tolerate. It's a personal decision.