Differential Brakes

[GraemeSmith]

So even on a 75ft wide runway and starting right at the edge - it's hard to get turned around and pointed the other way, maintain centerline AND minimize that amount of runway used. You have to snake back and forth a bit to get centerline. I hate leaving runway behind me and I'm a centerline junky! Also on tight ramps maneuvering can be tight. And at our overly tight ramp at the weekend - stopping and getting out to pick up the tail will really slow down things. And sure as heck not on a busy runway!!

I'm thinking TWO brake levers - one to each brake cable to help lock a wheel to get around. Though I'm still limited by how much I can persuade the tailwheel to skid around. For actual take off and landing - an interlock that will fix the two handles together that will lock out the differential and force the brakes to act together for take off and landing.

Pros and Cons?

The big Con being forgetting to lock the handles together. Though it can probably be done in a "deadman" way to make the brakes stay together unless you positively hold an override.

Input? - TIA

[caveman370]

Check out flyboy accessories. Podcast John Gillis and I have one with our tow breaks he designed. Works awesome! Spin around on a dime


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[Rofomoto]

I have installed two brake handles to do what your thinking

[WaiexN143NM]

Hi all,
Did flyboys come out with the kit? I talked to blake a couple months ago, he said they were working on it.

WaiexN143NM
Michael

[caveman370]

I think I have the RV one . He said he wasn’t making one for the sonex at the time because of complaints from some folks. Has a little bit different geometry to it . He said he would switch it out if I had a problem with it but I like it the way it is. Tail sits a bit higher is all. Very manageable


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[WesRagle]

Hi Graeme,

A little of topic, but are you getting full tail wheel deflection? The geometry is kinda complicated and so takes a little finagling to get it just right. As an example, here is a pic of the factory Onex rudder control horn a friend sent me.



I managed to get full tail wheel deflection on my Onex using the method described here:

http://sonexbuilders.net/viewtopic.php?f=21&t=4797&start=10

Here is a straight down shot of the tail wheel at full rudder deflection. If the angle doesn't at least match the angle of the rudder you may be able to get some improvement.



I was lucky and got the placement on the first attempt.



Obviously you will never be able to turn on a dime with the system, as designed, but you might be able to get a significant decrease in turn radius easily by optimizing placement of that one (or two, or three) hole.

Best of Luck,

Wes

[Brett]

I use two levers. Works great.

[GraemeSmith]

Thanks all!

[GraemeSmith]

Installed yesterday - similar idea to Rofomoto's picture above but the tops are folded out to form a "T" top which allows both to be held together - or by twisting my fist - more pressure on one of the other. Lower down at the attachment point for the cables I did have to "bulge" the bars slightly to allow the cable attachment shackles space to install and not foul each other.

To Wes's point about geometry - the builder got it close but the change required to get it 100% was about a half hole diameter and the chance of the plate looking like Swiss Cheese. I went with the brakes first.

Function test - the turning radius is down from 35ft to 15ft without the tail wheel chattering on the surface. I'm good with that.

EDIT

Added a picture of the left side of cockpit picture added to Airplane Flight Manual that shows arrangement

[N21X]

Ive been also contemplating the brakes and scenarios. I like the simplicity of the single lever but feel I will also need the differential braking. So I decided to install two mini valves one for the Left and Right out of the Single lever brake system that Sonex sells. So if I need Right brake for instance I will close the Left valve and vice versa.

I purchased two mini valve from Grainger for about $6.00 each. I'll send some photos once installation is complete.