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Questions before buttoning up the QB Wings

ERushing

ERushing

Well Known Member
Good Morning,

I'm ready to start riveting the bottom skins - finally! But before I do, I had a couple of questions.

1 - I've melted holes in the van's plastic conduit. I'm a little concerned about abrasion on the wires and AOA line that I have running out the hole. Has anyone come up with a good way to treat that hole to avoid abrasion? I've seem some use a braided PET sleeve. Any recommendations of source or particular brand? I have some leftover from RC builds but the stuff is cheap and frays like mad! Other ideas are welcome as well. (I've searched but haven't seen much in the way of recommendation.)

2 - Pitot Service Loops - The AOA and Pitot lines are a bit stiffer than I thought. How have people done and secured service loops? I've got my Gap 26 Pitot located one bay outboard of the pushrod access bay. Pitot/ AOA tubes are already bent and it's kinda tight in there...

E2098DA2-094E-4B46-B525-9FC4E2C072C8_zps6kiimwr4.jpg


Anything else I should think of before closing them up? I've got string run to pull wires, the AP servo bolted in, and the conduit permatexed in place. Also note that I'm going to secure that AOA line and heated pitot wires onto the heated pitot controller plate so it won't just be floating around.... I just need to figure out how I'm going to do the AOA/ Pitot service loop before installing the anchor.
 
While I'm sure it's obvious, make EVERY possible final connection and attachment you can before the bottom skin goes on. Working thru the inspection openings is darn tough and readily done only by dentists. :)
 
Rupester said:
While I'm sure it's obvious, make EVERY possible final connection and attachment you can before the bottom skin goes on. Working thru the inspection openings is darn tough and readily done only by dentists. :)
Click to expand...

I disagree. I like to run the wiring and install control system parts AFTER riveting the bottom skins. It is much easier to get your arm in a rib bay without the wiring and controls in the way. Installing the wiring and controls after the skins is a non-issue.
 
I purposely put the heated pitot controller on a removable plate so that getting into the Pitot bay would be a lot easier!

I do want to do at least an initial install and plan where I'm going to anchor service loops etc before buttoning things up.... hence my questions :)
 
I put the heated pitot power lines in a separate snap bushing and only used the conduit for wires that run all the way to the wing tip. I didn't like the idea of having to make modifications with that approach. There are quite a few wires that have to go down that conduit. I also would be worried that they will snag on your intermediate stop wires when you pull that bundle. I actually pulled my wingtip wires in a few pulls as I figured things out like the appropriate wire sizes. Everybody does it differently so whatever works for you.
 
I would test that you can remove the pitot with the skin clecoed on. It would be annoying if the pitot have to be replaced and it cannot be done with the skin riveted permanently on.

You mentioned you already have bent the tubes. I assume you mean the aluminum tubing coming out from the pitot itself. Garmin recommends minimum 8" of aluminum, how much did you keep ? Do you transition to plastic before, at or after the bulkhead ?
 
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Flame Retardant? Expandable Braided Sleeving

For any wires not in the conduit, I bought 50' of 1/8" and 1/4" Flame Retardant® Expandable Braided Sleeving from CableOrganizer. I cut it with a hot razerblade so it melts the end as it cuts to keep it from fraying. I run about a foot of it on the wires into the conduit. I then either zip tie, or use a little piece of heat shrink to keep it in place

http://www.cableorganizer.com/fireretardant/?gcssku=BSFR025
(If you search you can sometimes find coupons for cable organizer.)

I also added a nutplate on a rib near each of the access panels where I thought I might someday need a local ground.

Lynn

20151204_162828.jpg
 
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Nilberg,

I bent it with a pretty large bend radius. (Over my thigh :) )

I'm using the SafeAir kit so I will be flaring the end of the aluminum pitot probe tubes and using the H/W provided in the SafeAir kit to link to the plastic tubing.

Good point about being able to take it out with the bottom skin on! I'll have to look at that tonight!!
 
Don't use Phillips head screws to mount anything that has to be accessed thru an inspection plate. Use Allen or some other type of screw that captures the driver.

Hard lesson learned.
 
5/16 airline

Eric.
Not my idea but we ran airline the full length of wing on both sides for antenna coax. It would be very easy to install now but bit tricky with skin on...slip coax right through to tip...especially year later when we added vor wing tip to opposite wing tip. It fits perfectly in the formed rib support ( forgot number) without drilling any holes.
 
nilberg said:
I would test that you can remove the pitot with the skin clecoed on. It would be annoying if the pitot have to be replaced and it cannot be done with the skin riveted permanently on.

You mentioned you already have bent the tubes. I assume you mean the aluminum tubing coming out from the pitot itself. Garmin recommends minimum 8" of aluminum, how much did you keep ? Do you transition to plastic before, at or after the bulkhead ?
Click to expand...

I kept the full length of the aluminum tubing (2 pieces) (I didn't want the nylon tubing to melt when heat was on) on my Dynon pitot. A little thought to the bends, and it goes on/off with the skin on.
 
Bob,

That's exactly what I've done. Did you make a service loop in the vinyl tube that attaches to it? I can't see how to do it in that small bay so I think I'm just going to ease the pitot and AOA tubes back through the plastic bushing (pitot) and conduit (aoa) back to the wing root and make a loop there. If that does work out, I still should be able to get a hand back into that bay and disconnect the quick-connect fitting.

Jack - That's a great idea! Think I'll head to the NAPA Aircraft aisle this afternoon! I'm assuming you are referring to the j-channel, correct? Did you secure the airline to the j-channel in any way?

Thanks for the replies, guys! Right wing riveting starts tonight!
 
Eric
No attachment need except for where it enters and exits the wing. 5/16 may be hard to find at Napa...McMaster will get it to you next day. It is snug fit so installing now would save you some frustration if you go this route.
 
Thanks Jack! BTW - I think we've actually met. Possibly last year or the year before last. I was the newbie tagging along with Mark Cooper at the Prosser fly-in.

I do remember your beautiful '10 :)
 
Water line for antenna conduit?

So I looked at McMaster-Carr last night and came up empty handed. It appears that a max OD to fit under the curved portion of the j-channel is around 3/8. Stein's site stated that the coax OD is 3/16. I couldn't find an air line that met that criteria.

But lo and behold, I had some leftover polyethylene water line that is 3/8 OD and 1/4" ID which would seem to fit the bill rather nicely.

Anyone see a reason this would be a bad idea? I thought about fuel resistance but this thing doesn't need to be air or water tight. Just need to provide a stable path between the root and the tip and provide a bit of protection from the rib edges.

Best of all, it's free :)

Thanks for any feedback!
 
Ed,

I'm just starting to work on my QB wings and noticed today that there is a set of holes in the left wing for the pitot tube run, but not for the AOA tube. It looks like you ran the AOA tube in the wiring hole/conduit. Is there a reason for this?

I was thinking about drilling a second set of 3/8" holes for the AOA tube similar to the pitot holes already there. Anyone know of a reason not to do this (structural ?) or suggested best locations for these additional holes? I could ask Vans but figure I would check in with the community first.

Thanks
Dave Macdonald
 
How much extra pitot line do I need to keep at the wing root?
Is there typically a connector in the root area to connect it to a run in the fuse?
I wouldn't think that it would need to be one solid run all the way to its destination.

Looking ahead in the plans, I didn't really find any mention of this, although maybe I missed it.
 
I prefer to have no connection at the root (one less likelihood of a leak), and I usually leave a loop at the root that if I need to remove a wing later , it will give me slack to install a connector later.
 
In my RV-9A I have electrical wires running where your green pitot line is and I wanted to secure them in the bay where the aileron belcrank is. I made a couple (for top and bottom) of sheet metal hat shapes (about 3/8" wide) with a hole in each end. I mounted these to the bolts that go through the spar that fasten the tie down extrusion. Then used a tie wrap to secure the electrical wires to the hat section.
 
AOA and Pitot tube

Howdy,
I elected to use a bulkhead fitting for the aoa and pitot tube that was sold by Stein. If not when the lines get into the cabin there is only about 2" to make the bend and go forward. I do realize there is another place for air to leak though.

I also started with the Dynon heater controller mounted where you have it on the wing rib, but elected to change that to the access panel for ease of being able to service the unit. But, like someone else mentioned, at a minimum change the phillips head screws to allen or a bolt. Just make sure you can get to the unit for service
 
Fittings

I opted for the bulkhead fittings at the root for the pitot and AOA.

With the push on fittings that most are using, leaks are possible but not very probable. Is it another place that might leak, yes but where do you draw the line? Large trucks use many of those same fittings for their air brake lines and they are pretty reliable in that application with significantly more pressure...

In the end, it amounts to what you are comfortable with...
 
AOA Controller mounted to service plate

For the AOA controller, I mounted it directly to the service plate.
It makes future service easy.
Photo was taken before the alloy lines were bent .

8LL_jcEoWAHr9y-kFN66TV0vVvRPom0QkB-DLfzSvcD2SacRNBvACMjINt8tWUBrYWG4csg26bEegpC8y7yt6N1fDqkIffQB9TWxNZXnTCeEcZ1nzgNi5zmrGDWouB-ZE5uVbYaf4WVNYbPDDc7n35jFpb6eYJk7xHxPf74c_fBb_09cUkIFWvMS76sL6Ak1bwYQIal4pCkWcL6P3d-sYOu6Tlx053XPs_GR_DjMc_MnbdcCmMDx0HmLG2DRAIkiOPlJpqz0J_tS6mS0Pwgucuk5qAOwg-h0fWqUBnpXNIKGmo6WxdyTevkGat7gHWldsTlltu25iJPeYRe52tS--bawZBnwVYwxq0laOpUEhOMmzTqrk-Pc6Kw1ESVKyBhH0-g4CdaNzhnsQti5Yrgv-IXsMiw0hAl1rUlSJ8wa8BIszNlpE-3IfsZzIQXmLzLRfUWDaYL6HOY66eNk6KGmimcHvBhQuY-mgtRixRwCT9UbQcy4sMaE-FyHIu4gG3KcXF13l4B1gnssaymV-26qO8ouiuRZ70roLTuhDarxCP6oQPy-CyIDO3VaJKA-sBcYLDhRLiKmfXfYBR1cKvmFi3WxFp2mLkCLsIH2PXW28kjW8SzyGH48DNgkLr_JS06nX9px9B6FK1ORP4JWIiCHDn_Ggedb93G4IN7KZ7fUJMw=w894-h670-no
 
Dustyone said:
For the AOA controller, I mounted it directly to the service plate.
It makes future service easy.
Photo was taken before the alloy lines were bent .

8LL_jcEoWAHr9y-kFN66TV0vVvRPom0QkB-DLfzSvcD2SacRNBvACMjINt8tWUBrYWG4csg26bEegpC8y7yt6N1fDqkIffQB9TWxNZXnTCeEcZ1nzgNi5zmrGDWouB-ZE5uVbYaf4WVNYbPDDc7n35jFpb6eYJk7xHxPf74c_fBb_09cUkIFWvMS76sL6Ak1bwYQIal4pCkWcL6P3d-sYOu6Tlx053XPs_GR_DjMc_MnbdcCmMDx0HmLG2DRAIkiOPlJpqz0J_tS6mS0Pwgucuk5qAOwg-h0fWqUBnpXNIKGmo6WxdyTevkGat7gHWldsTlltu25iJPeYRe52tS--bawZBnwVYwxq0laOpUEhOMmzTqrk-Pc6Kw1ESVKyBhH0-g4CdaNzhnsQti5Yrgv-IXsMiw0hAl1rUlSJ8wa8BIszNlpE-3IfsZzIQXmLzLRfUWDaYL6HOY66eNk6KGmimcHvBhQuY-mgtRixRwCT9UbQcy4sMaE-FyHIu4gG3KcXF13l4B1gnssaymV-26qO8ouiuRZ70roLTuhDarxCP6oQPy-CyIDO3VaJKA-sBcYLDhRLiKmfXfYBR1cKvmFi3WxFp2mLkCLsIH2PXW28kjW8SzyGH48DNgkLr_JS06nX9px9B6FK1ORP4JWIiCHDn_Ggedb93G4IN7KZ7fUJMw=w894-h670-no
Click to expand...

Which "plate" is that mounted on?

Is it inboard or outboard of the aileron access?
 
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