Before finally installing everything, I laid out the pulleys their approximate relative distances they would be from each other once installed, to verify the idler position and where it will need to swing to tighten the belts enough to engage the pulleys on the track drive sprockets. From this angle you can see how moving the idler up would fully engage the brown belt (reverse spinning), down would engage the green belt (forward spinning).
It also became evident once I laid this out, that moving the idler forward or backwards (left or right in the picture) will loosen or tighten the belts at the idler rest position. Good to know when I make and position the idler actuator arm later.
I began assembling the transmission drive shafts. These are 3/4 solid steel rods, which I will need to cut a few grooves into for the pulleys keyways/set screws. So far everything is looking like it is gonna fit and align perfectly. One will be constantly sipping in forward, and the other in reverse when the motor is running. There is no sort of clutches or anything.
Here are both of the shafts. Once installed one will be right below the other one, and the pillow block bearings will bolt to the frame with the same bolts.
I will weld in some mounting plates to bolt the bearing’s to the frame, since the holes would weaken that 3/4″ tube too much. The white pulleys on the track drive sprockets are just set in place to show basic alignment.