Gear Leg brake fittings for 90degree turn out at caliper end

[Have-Purple]

I've been watching the Erin and Paul BH5 YouTube videos and noticed that the gear leg internal brake line exit point had an (new to me) elegant solution for running a soft line to the caliper. The picture below is not from the video and I'm not sure where I sourced it from, but it illustrates a 90 degree turnout exiting at the bottom of the gear leg.

I am trying to replicate this on my Companion. To the best of my ability, I surmise its simply an AN833-2 90 degree bulkhead fitting passed through one of the welded on tabs. Can anyone confirm? I mocked it up on my gear legs but the outside AN 37degree surface seemed like it would not be clear of the fabric after covering just based on the thickness of the gear leg steel tubing. Is there an easier solution I'm not seeing?

Thanks

Matt Brennan
UT9

 

[Dpearson]

On my BH4 I ended up making a little bracket to position the fitting the way I wanted it.

 

[kuss]

Here's two pics from the Erin & Paul BH5 taken at OSH this year if it helps...

 

[Bcone1381]

I'm flexible at considering what an industry best practice is on this topic. I exited the fabric with the hard brake line and just flared the end of the line with a sleeve and nut installed. Mine exits facing aft and loop around to the front with a flex line. This was my third design.




I rejected this idea. It was visually prominent and also ugly with extra unnecessary aerdynamic drag.

Here are some other shots I have to insight ideas.

 

[noema]

The less complex is just using a long flex hose (eg pegasus racing) from caliper to a bulkhead coupler at the gear hinge. Just stopping short with the fabric at the bottom leaves enough space that the hose routes well when using a 45 deg nibble.

​
Here is the inside view (the black parts are Techflex sleeves for shaving protection):

​

I believe I used 30" hoses for the gear legs. The teflon/stainless ones are quite reasonably priced. For other parts in the system I have ordered more hoses from Pegasus Racing. They always showed up in less then a week and international shipping was half of what ACS charges -- great company. There is a small weight penalty when using these but its minimal.

​(prices are from a few years back)​

 

[huntaero]

I welded a tab and welded a 90 steel fitting to the tab also took a bulkhead fitting used a lathe to spin off the hex nut bent it to approx 15 degrees and welded it into the top tube, makes a nice and solid attachement.

 

[Battson]

I've been watching the Erin and Paul BH5 YouTube videos and noticed that the gear leg internal brake line exit point had an (new to me) elegant solution for running a soft line to the caliper. The picture below is not from the video and I'm not sure where I sourced it from, but it illustrates a 90 degree turnout exiting at the bottom of the gear leg.

It's worth noting that calliper moves around slightly and has to be removed from time to time during maintenance. Also the space in there is quite tight, not leaving much room for access (think tools on angles to undo fittings) when tires are installed. Removing the whole tire + wheel assembly is quite a faff around, if you just want to change brake pads.... Further - the brake disc can get quite hot during heavy braking or a long taxi in a crosswind, so you want a heat-proof solution.

I would favour a smaller and more flexible solution, than the one pictured in the original post.

What Noema posted above, either with flexible hose or 3003 aluminium tube, works great. It doesn't require a fully flexible hose, but that doesn't hurt either.

The simplest solution is straight aluminium tube all the way from the fitting at the top of the gear leg, to the calliper fitting (as Bcone pictured above). This has stood the test of time and allows for easy maintenance. Remember to include an S-bend to allow it to flex easily.
The only downside is, if you break it somehow (not sure how this could happen, it's pretty well protected in there), you need to re-cover the gear leg to replace the whole tube, or install a union.

​

 

[joehmason]

That picture from the original post is actually my airplane. I used aluminum tubing from the top bulkhead fitting down to where it comes through the fabric. It does have an s-bend in it for flexibility. I did not use a bulkhead fitting at the bottom end due to clearance issues that Have-Purple described. Instead I adel clamped a standard 90 degree elbow fitting on the bottom tab, which cleared the fabric on the top side, and poked the threads through the bottom fabric. I doubled the fabric at that spot for strength. I then used a flex hose to come around the backside of the gear leg to the caliper.

I like the flexible line for disassembly. The caliper can be removed and swung clear around to the inside of the gear leg. The line also stays protected from brush and grass by the gear leg and strut. It has worked perfectly so far.

Phenix Fittings has PTFE lined flexible hose specifically designed for brake lines. They also have all sorts of fittings so you can custom make hoses. I found their products to work extremely well.

I looked for a picture but cannot seem to find a good one before we covered.

 

[rodsmith]

Joe, sent you a PM

 

[Have-Purple]

Oooh.. I really like this implementation. Where did you source your software lines?

 

[Have-Purple]

Thanks for the original pic and the write up Joe.

 

[Dpearson]

The stainless lines came from Pegasus Racing. Haven’t tested them yet, but visually they look great.