For the tail wheel bracket I see they have different springs (the part that attaches to the rudder) availeable for steering. One is "Heavy" and the other is "Light". How do they perform differently?

The heavier spring will make the tailwheel turn more quickly than the lighter spring. It could make the plane hard to handle on the ground. You'd just have to try them out and see.

does it help any on turn radius?

On both my 4*s I used the heavy spring. The mistake I made with the 4*60 was to leave the spring long and I had very little ground control due to the flexing of the spring. I later made some mods that helped some. Thats the pic of the blue plane.

On my 4*40 I shortened up the spring quit a bit and it definitly works better. The Teal plane.

The ratio of rudder movement to tail wheel movement will affect turn radius. The stiffer spring should make the wheel follow the rudder more closely, making the radius tighter. Another function of the spring is to isolate the rudder servo from the shocks transmitted from the tailwheel. The stiffer spring willtransmit more feedback to the servo.

Some setups don't use a spring. They track the rudder exactly, but the servo pays a price, IMO.

Faulknej,

Where did you get those nylon brackets on the rudder?

Hmmmm... I let the tail wheel move freely with no springs and have absolutely no trouble with ground steering.

CGr.

They came with the hardware in the ARF.