Hey cflight, Eureka i have it,heheheheh, the idea came to me working in the shed yesterday,very simple very strong and wheel size wont be an issue.
I was cutting a five horned servo arm down and it hit me.
Take the wheel off the truck, mount the sevo arm or something stronger same shape,aluminium?to the axle fit five bolts with locknuts on the arms then the drive/tank sprocket is attached to the servo arm with the five bolts ,this means the track system can be made with a drive sprocket two idler wheels, airplane wheels would work and a small tensioner wheel.
And it can be any size and acomodate any track size.
The unit.......
Two triangle plates with the wheels inside mounted on threaded rod and bearings. the triangle would have a smaller triangle out front and just above the front idler wheel, two brackets and screw thread will adjust and push the small tensioner wheels against the track much like the mattraxs.
The aluminium triangles could be any thickness and size depending on truck size/track size or wheel diameter. this method would be the strongest of all the designs and really easy to build also you can mount a shock to the back of the triangle and attach it to the truck swing arm. what do you think????
Have a look at the yellow mattraxs unit and imagine two triangles both sides,
Rickster.