One of the tweaks that I needed to do to get the time lapse rover working was come up with a coupler that went from 8mm to 1/4" so that the stepper motor shaft would connect to the 1/4" D-Shaft. I originally could only find ones that didn't have a set screw, and the shaft would slip under any torque from the motor.
I settled on buying a coupler from ServoCity, and then drilling out the side so that it would fit the 8mm shart, since they didn't sell one that fit onto a stepper motor. There was still a bit of play in the shaft under pressure, and I found myself constantly tightening the set screw.
I finally came across what I was looking for, and ordered an 8mm to 1/4" aluminum coupler from ebay.
Unfortunately, the new coupler had too big of diameter, and I couldn't mount it like I did previously and just replace the old coupler. I made the decision to make some design changes, and mount the stepper motor in reverse, and use the NEMA mount from servocity on the back, versus on the shaft side like I did originally. Luckily, the D-shaft that I used initially was still the right size and everything is mounted more securely and firm.
The emotimo TB3 time lapse rover is now back in action and ready for testing once again.
If you haven't seen what the rover can do, here is some recent footage from Two Medicine Lake in Glacier National Park.
