Belts and idler positioning

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.