Aeroconversion brake performance?

[Kai]

Mike- agreed!

Until you compare the props, it does not quite add up. But do not forget that power (hp) is a derived entity: output shaft torque is what matters!

If you compare the tiny Sensenich toothpick 33A prop to the fat paddleblades they supply for the Rotax range, it is somewhat clearer. The difference in torque between the two makes is astounding! And, bearing in mind that this engine range should preferably be run with a 3 blade ga prop, which many do, it becomes even clearer. In the beginning of the t-o run, adding full power- be ready with your right foot!

But, as always, seeing is believing: go and check it out yourself!

Thx
Kai

[mike.smith]

I'll believe you. I was just trying to make sense of the numbers. :-)

[13brv3]

Have you been asked what is the best modification you have made to your Sonex? My answer would be using the Sonex hydraulic brakes and the O'Keefe hand lever master cylinder. http://www.okeefeaero.com/-hydraulic-brakes.html

I fly a OneX, AeroVee & Sensenich prop.

Hi Michael,

When you say hand lever, you're not talking about the motorcycle type lever like this are you? https://www.aircraftspruce.com/catalog/ ... ckkey=3750 If so, I'd love to see how you made that fit. I got one and it's beyond hopeless as far as I can tell.

I ended up ordering one of the dual hand levers like this https://www.aircraftspruce.com/catalog/ ... nders2.php and when it gets here, I'm just going to go straight to differential toe brakes. Not sure exactly how, but I've got some ideas that are similar to what Scott did.

Rusty

[Kai]

All,

Like David notes- differential with two ø1/2’’ masters is the way to go: provided you can access the rudder pedals in the finished plane, AND you go to a castoring tailwheel.

This last issue is of some importance: if you neglect it, what will happen is that the rivets keeping the rudder horn (which is also controlling tailwheel swing) in place at the bottom of the rudder, let go. There should probably be some sort of bolster plate on top of the rudder bottom rib, so that the rudder horn rivets can’t deform the bottom rib and work loose. We have previously recorded one such situation, discovered during a D.I.

Another option for the Sonex setup: would it be possible to retain the MCP master, but make some sort of bushing and corresponding piston for it, for diameter reduction??

Thx

[13brv3]

Differential brakes and full swivel definitely go together, and they were both on the list of things I'd upgrade to eventually. If I end up with diff brakes now, the upgraded tailwheel won't be far behind. I was looking at the Van's assembly, but they seem to use a 0.635" spring so the socket would be a bit oversized for the 0.625" spring.

I had also wondered about a smaller piston for the MCP master. Heck, how hard can a master cylinder be to make with the right tools? When I ordered the brakes from Sonex, I didn't bother ordering the master since I knew I wouldn't use it.

I have thought of another scenario that would be acceptable though. The Sonex brakes come with a valve that's meant to be a parking brake. You apply pressure, then close the valve holding the pressure to the wheels. I would be fine with the separate brake handle they normally use if you also had that parking brake valve. That would allow you to have enough hands for a run-up, and also still work fine for normal braking.

Rusty

[XenosN42]

Hi Michael,

When you say hand lever, you're not talking about the motorcycle type lever like this are you? https://www.aircraftspruce.com/catalog/ ... ckkey=3750 If so, I'd love to see how you made that fit. I got one and it's beyond hopeless as far as I can tell.

I ended up ordering one of the dual hand levers like this https://www.aircraftspruce.com/catalog/ ... nders2.php and when it gets here, I'm just going to go straight to differential toe brakes. Not sure exactly how, but I've got some ideas that are similar to what Scott did.

Rusty

That is exactly the type I was referring to. A picture of it was included in the link (to the O'Keefe site) in my previous post. It appears to be the same as the one you link to on the Aircraft Spruce site. The only difference I can see is that the O'Keefe price is $179.95 and the Aircraft Spruce price is $204.95

I installed it about 5 years ago and don't have any memories of any problems. I did have to cut off about 1 inch from the top of the handle, so that it would clear the bottom of my instrument panel. ( I have a OneX.) The metal is aluminium so that was easy. The only downside to shortening the handle is that a bit of leverage is lost. Not a big deal for me since my hands are larger than average. You can see the brake handle in action at the very end of this video https://www.youtube.com/watch?v=crqD37tvz0I

[13brv3]

Interesting. Maybe I need to take another look, but I sure didn't see any way it could fit. I did move my panel back about 1", so that compounds the tall lever issue.

Thanks,
Rusty (Onex 912UL)

[daleandee]

Interesting. Maybe I need to take another look, but I sure didn't see any way it could fit. I did move my panel back about 2", so that compounds the tall lever issue.

Thanks,
Rusty (Onex 912UL)

Rusty,

I have the single hydraulic master cylinder with the "motorcycle type lever" on the center stick of my Cleanex that operates my Tracy O'Brien hydraulic brakes. I did shorten the handle and rounded and smoothed the cut end. It has worked very well for 10 years. You can see it clearly in this older video of mine (~9:00) and if you watch the landing roll out at the end you can see how I use it. Tracy's brakes work well but they can get warm and begin to fade if you ride them too heavily.

https://www.youtube.com/watch?v=0afcagd70UE

Dunno if this helps ...

Dale
N319WF

[13brv3]

Thanks Dale. The Onex is quite a different arrangement from the other models it seems. Turns out I only moved the panel back 1", not 2" like I originally posted, but you can see the problem. If the assembly is installed high enough to clear the angled part of the stick, then I'd have to cut off nearly half the handle. If you mount it lower, but angled to the side, you can still only gain about 3/4" because the cylinder will hit the spare on full up elevator. Unless the one I got is larger than Michaels, I have no idea how he made it fit.

Rusty

[XenosN42]

Interesting. Maybe I need to take another look, but I sure didn't see any way it could fit. I did move my panel back about 1", so that compounds the tall lever issue.

Thanks,
Rusty (Onex 912UL)

Sometimes a picture is worth a thousand words. Here is a picture of my brake setup (with the parking brake engaged, that's the thin angled piece attached to a piece of string). My OneX panel is installed per plans. I can push the stick forward all the way to the elevator stop. As I mentioned before I did have to cut off about 1" from the top of the brake handle. As you can see from the picture the mount has to be set slightly to the left to clear the angled portion of the stick.