Printable View
Thought that I saw some photos where some of you drilled holes in the spar to run wiring, where would I find them? I am putting my ADAHRS in my wing and need to run the network cable and the static line into the fuselage. I have the 15 foot network cable so I can't take it to the end of the wing tip and back unless I was to get the 30 foot cable. Any thoughts?
As a rule you never drill top or bottom on a round spar unless your mounting a strut brace, your filling the hole with a rivet and adding a plate, inside of your spar at the strut mount there is an I beam, if I had to drill a hole on the rear spar it would be on the leading edge close to the strut bracket
First, I am not an engineer except what I learned as a Dentist - bridge building.Quote:
Originally Posted by SkyPirate
From what I understand this is typical advice. the stresses on a wing would be tensional stresses and would be the caps - top between root and bracket and bottom bottom outboard of the bracket.
I might have a little different thought on this one. The greatest point of stress on the spar of a strut designed wing would be at the strut attach bracket. I think I would go inboard or outboard of that. I do know that in the Model IV book, the spar was drilled to pass the pitot tube tubing and it was outboard of the attach bracket about a foot.Quote:
Originally Posted by SkyPirate
Again, this is just from an amateur.
Yes when I said near the strut bracket I should have been more clear, "close" = inboard , your between the main strut and jury strut and with in the area of the inner I beams added strength
Personally I wouldn't drill holes in the spar anywhere except on the extreme ends (and I am a mechanical engineer). I know several guys who ran wiring and even pitot tubing outside the spars and were able to snake it around the ribs and fuel tank (on model 7). I believe this is a better method if you can't run it inside the full length of the spar.
I did the same as Jiott mentioned....ran wires & pitot plumbing behind the fuel tank on our 7 just ahead of the rear spar & snake through the ribs & secured with a compatible adhesive...a service loop of the wires at the inboard end of the wings made an easy design for folding the wings (attached).
The skystar build manual for the 7 said to drill a hole in the spar for the tube running to the pitot.....I could not bring myself to drill a hole the spar...not an enginer either but lots of experience with metal & fabrication of stuff.
Sincerely,
Dave S
KF7 Trigear
912uls warp drive