Brake line routing through fabric

[PapuaPilot]

I'm looking for pictures of how people have made the brake lines pass through the fabric. I tried searching that on the forum and came up empty. :(

Does anybody have a good picture of this. I want to have fittings at or near the fabric so I can disconnect the brake line if I ever wanted to remove my landing gear.

[n85ae]

I don't have any pics, but what I did was cut some aluminum sheet with a
hole for the line to pass through, and then glued it to the fabric.

Jeff

[Dorsal]

What I did (as per the instructions as I recall)
http://www.teamkitfox.com/Forums/picture.php?albumid=202&pictureid=2410

[mr bill]

This is what I did.

[Dave S]

Phil,

This is with the grove gear on a S7 trigear....

Here is a photo of the Starboard side where I ran the tubing through the fabric just in front of the rocker on the gear leg (approximately 2 inches from the end of the rocker). The idea for picking this spot was to put the penetration in line with the centerline of the rocker to minimize the amount of vertical motion the joint is exposed to due to gear flex. Second point is this location goes through the fabric where two pieces of tape overlay so no need to have a separate fabric reinforcement (per poly fiber manual). The red stuff is a dollop of red RTV to seal and hold the line at that point.

Second photo is the outside of the same penetration looking from the front. On the outside the tubing makes a turn towards the 90 degree fitting on the gear leg.

Port side is similar but don't have any photos of that.

PS - the white tape under the zip ties in the fuselage is hockey stick tape - a frugal choice to keep the zip tie from sliding or wearing on the tube.

Sincerely,

Dave S

KF7 Trigear
912ULS Warp Drive
St Paul, Minnesnowta

[neville]

I used plastic cable fairings from Aircraft Spruce. Put in two sets, one for trigrear and one for tail wheel.

[PapuaPilot]

Thanks guys, this has been helpful. The Grove gear is different on my model 5. It doesn't have the threaded hole and gun drilling like yours does. You have a nice solid point on the gear leg to attach the line to.

My gear leg just has a half round flute cut out on the trailing edge of the gear leg that the brake line gets glued in. The instructions say to make a hole in the fabric, glue a rubber grommet in the hole and use brass elbows through the grommet. The problem is that the Nyaflow brake line is really stiff and is going to put pressure on the grommet and fabric. I'm concerned about it pulling out or tearing the fabric.

I think I need to glue some aluminum to the fabric like Jeff (N85AE) said and create a hard point to solidly attach the brass elbows.

[Pilot4Life]

PapuaPilot,
I know the drawing is crude at best, but perhaps this will give you an idea and spur a thought/direction. If possible, install a doily re-enforced thru grommet in which you could install AN fittings to make this possible. The AN Fittings with proper washers clamping fabric may suffice, but I would re-enforce fabric with a small doily. This should allow installation without over stressing the brake line and remove the risk of the fabric being damaged from the rigid brake line shifting. Just my 2 cents...

7864

[Jch]

While I was building my SS7 i had the same question. How to make the tubing make a 90 degree turn below the floor board and pass through the fabric. John McBean explained how to put something like a large gauge copper wire in the tubing to keep it open, heat it carefully but dont kink it, and bend the tubing and wire to 90 degrees then remove the wire. With little or no experience with this I did it, I had a 90 degree bend, the tubing remained open and it has worked very well for 106hrs now.

[jiott]

Don't forget that the Grove gear flexes maybe up to 1" in this area so the brake lines must be able to also move this much without pulling/pushing too much on the fabric.

[Jch]

Hmmm, I never considered that. I wonder what the brake line tubing and fabric have been doing while the Grove LG has been flexing? Could the tubing pull out of the 90* fitting?

[jiott]

To avoid pulling out of the fittings, you would want to lay it out so there is no pulling force on the brake lines as the gear flexes and the lines either slide freely thru the fabric or flex gently sideways. I would avoid gluing or fixing the lines at the point they penetrate the fabric.

[HighWing]

Don't forget that the Grove gear flexes maybe up to 1" in this area so the brake lines must be able to also move this much without pulling/pushing too much on the fabric.

Check this video:

http://www.groveaircraft.com/droptest.html#