SonexBuilders.net

I understand the new Sonex Model B cones with hydraulic brakes
BUT
I would like toe brakes at the other end.

Where can I buy Toe Brakes for the Sonex Model B (NOTE: I'm not a welder.)

advTHANKSance

Dkb

I have toe brakes on my Model A, and I would NOT do it again. They are a royal pain to bleed, and you can only do it with the tank, windscreen and glare shield out. You can mitigate this a little by installing a reservoir, but still...

Bingleis' books have some ideas for fabricated toe brake pedals, that pivot on the top of the rudder pedals, perhaps on phenolic or plastic blocks.
http://www.eaa.org/shop/product-detail?i=941&pi=926&pr=2516202
http://www.eaa.org/shop/product-detail?i=941&pi=926&pr=2515945

Toe brakes can be made to work and be easy to bleed from the bottom up. I have teflon tubing installed on the master cylinders which act as the reservoir. On bleeding, the ends of the tubes are placed in a bucket and fluid is pushed up from the bottom under pressure until no more air bubbles come out into the bucket. I can see the fluid level just looking underneath the panel which I do on every preflight.

The Sonex hydraulic brakes are not very powerful. They can not be used to keep still during run up or for crosswind corrections when landing (or taxiing). I switched to OKeefe brakes and those work.

I welded up 4130 tubing to make the pedals. Any welder can make up a set.

Rick Caldwell
Xenos 59 hrs

My Aeroconversions hydraulic brakes hold fine for runup with my Aerovee.

Rick, I have had the the O"O'Keeffe (formerly Great Plains) brakes on mine for the last 12 years, and have their cylinders rigged as toe brakes. They have worked fine, but I bleed them by backing off the fitting at the end to let out fluid and air while pumping in from below. That means crawling under the panel to release those fittings and slip[ on a line to a catch bottle. Sounds like you have a bit of an improvement on that. Do you have a check valve installed on the cylinders in place of the standard fittings or ???

Also: Just looked up O'Keeffe brakes and see that O'Keeffe Aero no longer offers these and the entire business is up for sale. :-(

David A.

I picked up a set of Matco brakes and wheels from a guy on VAF who was upgrading to Berringer. I have seen a number of these come up at around half of new order, mine were still new in the box. They seem like nice units to work with and I have them plumbed to a reservoir forward of the firewall, which made bleeding pretty easy and mess free.

Gordon

David,

I don't have a check valve. I have a plastic cap on the end of the tube but it is loose enough to let air in as the fluid is displaced. I have Matco master cylinders. I fill from the brake caliper upwards using a pesticide plastic spray tank as my pressure source for the brake fluid.

I started this tube reservoir concept when I had my One Design. It originally have a firewall mounted reservoir but that made a mess when the vent on top leaked during neg. g's. The tube concept worked much better. I have a syringe with a small tube attached so I can inject more brake fluid into my "reservoir"
tubes. So far on the Xenos I have not needed to add any fluid.

Rick Caldwell
Xenos 59 hrs
CAmit 3300

I just found air bubbles in both my brake lines. I would not have seen this without the tank being out to re-route the engine controls, and I can't bleed my cylinders with the tank and glare shield and windscreen in place.
https://photos.app.goo.gl/gPdSmFGRkBeCBM887

I'm looking at ripping out the toe brakes and replacing the existing Tracy O'Brien masters with an Aeroconversion master - one handle for both brakes. http://www.aeroconversions.com/support/instruction_sheets/AeroBrakes_Installation.pdf


Apparently this is supplied with the Model B kits. Anybody have it installed? Pictures?

I have center controls.


viewtopic.php?f=3&t=7079

I have the B with the aeroconversion brakes. They work well at runup and the turn radius is fine. If I see air in the lines I pop the cap on the res and pump the handle which actually pulls the air back to the res and out the fill. The tubing tees at the firewall. That's "plastidip" on the handle. Years back I was persuaded to install tow brakes on my Sonerai 2 (similar size, speeds, weight etc) after having flown it for few years with just the single handbrake....a few hours later I pulled them back out...