Thorp Air Command - T18.net

Guys,
On my previous post I mentioned that my new tail wheel assembly is releasing before I get to full rudder travel. The wheel releases at about 33 degrees but the rubber horn will turn the wheel 45 degrees when the rudder turns 30 degrees either way. John mentioned that others have lengthened the slot in the tailwheel to address this. I searched the archives but it looks like the old stuff does not capture much past 2010.
This got me to thinking though. Do we want the tail wheel to be turning more than the rudder? Thinking back to my Stinson, the the rudder/wheel movement was closer to a 1 to 1 ratio.

If you remember what you did to your tail wheel slot I would appreciate knowing, and also your thoughts on having the wheel turning more than the rudder.

Best regards,

Jim

I tried to reply yesterday, but it didn't post for some reason. I milled out my tail wheel boss to 45 degrees. I love it. The only time you will have that much rudder in is very slow speed such as doing a 180 in the run up area. To be honest, I do not know if my rudder moves less than the tiller. I have the standard set up on long gear. Works for me. Might be a little sensitive for others.
Cubes

I have not done anything to my AP tail wheel . If I need to make a tight turn I hit that pedal and before the turn is completed I jump on the opposite pedal/brake and "bump" the brake to stop the turn and the TW straightens itself out . On occasion a little burp on the throttle helps ! I have not had any problems during taxi , TO or landing with the TW ? BATA BING , BATA BOOM !


RB

The problem I have had, is if you really have to apply a lot of rudder, such as when landing with a gusty crosswind, the darn wheel can break free when you really need it. I found the modification to be necessary for me. There have been a few times with strong winds, when I needed almost all the rudder & some brake. I try to stay out of those situations, but around here I'd never go flying as much as I want to if I didn't risk that possibility once in awhile.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

James and John,

I was wondering if your cutter path was an arc or was it just a straight cutter path? I assume the point where the two radii meet it was at 45 degrees?( the straight through bore and the key cut out)

Thanks

Jim

Jim,
I did it straight. The existing cut-out is a semi-circle. I used a 5/8" end mill & positioned it in the center of that cut-out, then went about .020" (don't remember exactly, but I think that's close) from center on both sides, basically flattening out the curve in the center & extending the cut-out on each side. I hope that makes sense to you. If you take the assembly apart, I think it will be clear. Hope that helps.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

Very important! Look at the ramp on the ends of the current cut. You want to match that. That will determine how much pressure is required to break the tail free once you hit the stop. All we did was match the current cut out and just extend it to a 45.
Cubes

Thanks guys. I should be able to figure this out now.

Best regards,
Jim

Here are a couple of pictures of an unmodified hub, Jim. the cut-out was obviously made with a 5/8" diameter end mill. If you use one of those, locate it in the existing cut-out, then go about .020' in both directions (left & right), it will probably be close to what you want from my experience. You may have to go a little more in each direction to get exactly what you want. A little goes a long way... .020" is not very much material to remove, of course. The action of the lubricated key on the "ramps" will be fine. There are more complicated ways to do it a little differently if you so desire.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

Nice nails ! Do them yourself ?

RB