Adel clamps from Ace... Bad idea? And some conduit questions.

John Courte · #1 12-14-2007, 10:32 AM

Hi. I'm running PVC conduit along the wing through the big lightening hole, low and aft. Bellcrank/pushrod clearance looks good, and I was able to fab a bunch of brackets from a spare HS fwd spar. I have a bunch of 1" Adel-style clamps (conduit is 3/4 ID 1" OD) left over from a home-improvement job I did a while ago, and I was considering using them to secure the conduit to the brackets. The only obvious gig is that they're galvanized steel instead of Aluminum like the ones Spruce sells. Spruce's are also much cheaper, but I already have these. Am I risking a huge galvanic corrosion hazard by using steel clamps on aluminum brackets? Is the cheap Chinese steel too brittle to use in an aircraft?

The reason I'm using such big conduit (3/4 is kinda huge) is that I really have no idea what I'm going to need down there at the wingtip as far as wiring goes, but I'm leaning toward wingtip LED nav lights, HID landing lights, and strobes, possibly an antenna, which makes for a decent sized bundle running outboard.

Thanks in advance,
-John

JohnInReno · #2 12-14-2007, 10:42 AM

I used CPVC which is lighter and stronger than PVC. I mounted it with grey plastic pipe suspension clamps from the plumbing department. They were in bags of 6 and cheap.

Rick6a · #3 12-14-2007, 10:51 AM

Quote:

Originally Posted by John Courte

........wingtip LED nav lights, HID landing lights, and strobes, possibly an antenna, which makes for a decent sized bundle running outboard......

John,

Although you may have to fit a BNC connector on an antenna cable after it is run through the conduit, all the circuits you mentioned can be accomodated inside Van's lightweight conduit, and especially so if you locally ground some of the wires.

http://www.vansairforce.com/communit...ad.php?t=14523

Greg Arehart · #4 12-14-2007, 09:28 PM

I just used half-inch irrigation line (0.620 OD), enlarged the existing wiring in the ribs to 0.625. Nice tight fit, lightweight, no clamps needed.

greg

sportpilot · #5 12-14-2007, 09:51 PM

It sounds pretty heavy to me. The flex conduit is very light compared to PVC and tie wraps are much lighter than adel clamps. One tip is use thin strong string and maybe wax it to pull your wires with. As the conduit begins to fill up any twists or kinks in the wires , or a fat pull cord will begin to seize up and lock tight.

John Courte · #6 12-15-2007, 07:44 AM

Thanks for the input, folks. MUch appreciated.

Since these are QB wings, the prospect of drilling through all the obscured ribs doesn't appeal to me, and the 3/4" conduit doesn't weigh any more (practically) than the 1/2" pvc. I did decide to forego the Ace Adel clamps, I have some aluminum ones on the way from ACSpruce, in the midst of another order anyhow. There were $0.46 each, so no big deal.. I also thought about using irrigation line, but I'm not comfortable with its flexibility and it might interfere with the bellcrank if run through the first lightening hole aft of the main spar, which is my preferred location.

andrew phillips · #7 12-15-2007, 08:06 AM

I have QB wings and I used a piece of plastic pex water line as conduit. For clamps I took a piece of sheet aluminum cut to approx 1" x 2.5" and drilled 2 holes. ! hole is the size of the pex and the other is a rivet hole (#30). I slipped these over the pipe at both ends at everywhere I could reach through access holes and used pop rivet to hols them to the ribs. Don't know how long they will last in the real world but it seemed like a good idea at the time.