Matco tailwheel quetion

[109JB]

I'm replacing the Maule tailwheel with an 8" Matco single arm tailwheel that I bought from one of the fine members of this forum. I was mocking it up a little tonight and it appears that at full rudder travel it probably won't be able to unlock and it may need the optional "25-degree wings" to get it to unlock. Just wondering how many using the matco tailwheel have needed to get the optional wings.

Thanks,

[Av8r3400]

I'm running a standard 8" mono-arm Matco wheel. It locks and unlocks just fine.

[ken nougaret]

I have the same, stock Marco single arm. Never a problem.

[n85ae]

Maybe just the picture, but that tailwheel mount on N826DM looks far too extreme a pivot angle
to my eye. If correct, I bet you would get a lot better steering if you changed spring, or made
the angle less severe.

Jeff

[JohnB]

I changed mine to the 25 degree cam arms and it was an improvement. I could get it to unlock with the stock cams but it took a lot of brake pressure to overcome the spring tension enough to hit the 40 or so degrees of tailwheel travel needed to unlock. Then it would be quite a snap when it unlocked. I do keep my chains pretty snug, so maybe looser chains would make it easier to unlock.
With the 25 degree cams, it just takes full rudder deflection and a little brake and it unlocks much more smoothly.

[jrevens]

Maybe just the picture, but that tailwheel mount on N826DM looks far too extreme a pivot angle
to my eye. If correct, I bet you would get a lot better steering if you changed spring, or made
the angle less severe.

Jeff


It looks just about perfect to me Jeff. That amount of angle, in that direction (positive caster), is actually preferable to the opposite (negative caster). Keep in mind that the spring is going to straighten when there is a load in the airplane, and it will probably be at the optimum angle then. It may seem counter intuitive, but angled as you see in the picture is considered better than the other way, and I can confirm that this was true for a couple of different airplanes I flew before and after being corrected to what I've described. Both had a propensity to shimmy before correcting. Here's a good article explaining it - http://inspire.eaa.org/2019/03/20/tail-wheels-what-can-go-wrong/

[Av8r3400]

Maybe just the picture, but that tailwheel mount on N826DM looks far too extreme a pivot angle
to my eye. If correct, I bet you would get a lot better steering if you changed spring, or made
the angle less severe.

Jeff


As John mentioned that angle is more than acceptable. I have never had (with exception of a flat tire) any shimmy issues and the steering and castering features work excellent.

[n85ae]

I understand well how the angle affects shimmy, and steering.

The angle is in the "correct" direction, it just looks to me to be excessive. However that said, I have not
been at the controls of your airplane, nor have I used a Matco tailwheel. It simply looks like it is at an angle
far beyond what you need to correct shimmy, and to the point where it would hinder turning.

Seriously though - If it works, I can't argue with that :)

Regards,
Jeff

[109JB]

Thanks for the replies.

With my previous model 4-1050 I switched to the 25 degree arms at it was tons better. The horn on the rudder of that airplane was different from this one, but I was not able to unlock the tailwheel on that airplane while taxiing and braking and could only get it to unlock with the stock cams with a very forceful push on the fuselage, or kicking the tailwheel. The 25-degree arms made it so that taxiing you could give full rudder, step on a brake and it would unlick as expected. Ground handling was also a breeze.

On this airplane, I mocked up some springs and the rudder and it appears it is going to be the same thing. I think I will go ahead and get the 25-degree arms.

Thanks again for the replies.