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View Full Version : Matco tailwheel spring tension and allowable offset?



LSaupe
03-12-2016, 01:32 PM
I have a Kitfox III with an 8" Matco single arm tailwheel.

My wife is training on the bird now, for her tailwheel endorsement, and commented on why there is some left pedal required for it to track straight. I just never noticed it before. With the pedals even (rudder is then true to the vert stab) the plane will drift off right. When raising the tail (by hand) the rudder and tailwheel all line up well, however, during taxi (even on coast with idle) you need to add some left pedal (rudder and tailwheel now slightly misaligned). Anyone experienced this before?

I added a link to my right chain and it now taxis perfect (with regard to pedal position). Right chain now has zero tension and left the original 1/2" (unsprung length is 2.75"). Right side spring length is 2.75" and left side compressed to 2.25" (with everything aligned - Rudder to tailwheel straight ahead). Not sure I want to fly like that, but just for a point of reference. Prior to the change both were at 2.25"

Gear alignment is perfect and no dragging brakes issues. Kinda odd that the Matco tailweel is offset to the right of the centerline though (maybe due to the single arm?).

Do any of you run different tensions on your chains?

If so, anyone know what the recommended tension is for the Matco? The supplied chains are rather crude (each link worth 1/2" of distance).

Jono
03-15-2016, 03:39 PM
Hi LSaupe,

I'd always put this down to the fact that it was a single arm on the tailwheel. Not sure if that is why, but I'd always figured it was that.

Jono
03-15-2016, 03:40 PM
ohh... and nope.. same tension on both side

LSaupe
03-16-2016, 06:00 PM
Jono: Did you experience the same thing (or know someone who had)?

Jono
03-16-2016, 09:36 PM
Jono: Did you experience the same thing (or know someone who had)?

I've since changed tailwheel, but I think you're right I think it would pull slightly to the left (occasionally)

Peteohms
03-18-2016, 07:18 AM
I have the same tailwheel on my plane and have no issues. Way better than the Maule.

Floog
03-18-2016, 11:57 AM
For what it's worth I have the Matco on my KF7 with 680 hours of "normal use" and no issues. I'm delighted with it. A squirt of grease occasionally and check the air. I have the original kit springs and chains. I set them up equal length and slightly slack. (No tension on the springs. So I don't care if one comes off.) The plane tracks straight, steers awesome, disengages/engages when it's supposed to. I prefer wheel landings which saves wear and tear on the tail wheel. If you're a "full stall landing" style, perhaps the tail wheel assembly should be more robust. My hat is off to Mr. Matco!

Olle1975
03-23-2016, 05:23 AM
I have a Kitfox III with an 8" Matco single arm tailwheel.

Which engine do you use?

Olaf

Peteohms
03-23-2016, 04:47 PM
Which engine do you use?

Olaf

912 80 hp.

Olle1975
03-24-2016, 02:40 AM
Hi!

Sry, my question was addressed to SLaupe.

I think he use a Rotax 582 like my Kitfox III. I have to use the left pedal to taxiing straight too (Matco 6"). We have a left hand turning prop and I think the torque for our "small" engine could be the reason for it.

Olaf