When I originally built the time lapse rover to work with the eMotimo TB3, the only option that I could figure out was to have the gears outside the frame, and have the stepper motor mounted parallel to the back axle. This wasn't pretty and based upon that original design, the rover was only 1-wheel drive.
The motor and gears hung off the back on one side of the rover. Not ideal, but it worked.
Recently, ServoCity released a new bevel gears that would allow me to create a much simpler drive mechanism and keep everything tucked within the frame. I also made the change to a longer d-Shaft that now makes the rover 2-wheel drive. The Stepper motor is mounted underneath the main support beam perpendicular to the back axle. I also changed the way that I mounted the wheels, and brought them closer to the frame, as I figured there was no reason to extend them out the way they were previously.
I'm also using the new stepper motor mount. Having a motor that has a gear reduction box made it tricky, and I suppose that I could have reversed the shaft to come out the bottom to make it easier. It's a solid mount to the back axle with a small channel spacer to provide room for the 3/8" to 1/4" coupler. The back axle is fixed now, and only the front axle can rotate.
The 3/8" threaded mount was rotated so that the TB3 always sits on the rover with the input ports positioned to the back. This creates a cleaner path for the cables, and always bothered me a bit to have it mounted on a diagonal. The GoPro mount is still on the front, and the 3/8" screw is ready on the back in case I want to do a scorpion mount for the flexible GoPro mount.
The bevel gears are smooth the rover feels more solid now. With the wheels moved in, and the motor tucked underneath, the rover is a svelte machine. Hope to get out and play with it more soon!
