This was a fun project and pretty cheap!
I used CL to buy a used instax mini 8 for $25 and took about 8 hours to make. It required a lot of dremel work to cut away parts of the instax. I got rid of the lens but kept all the gears that turn the rollers. At first I assumed I would need to rig up a crank to turn the gears but I ended up rewiring the motor to the shutter switch so I just need to hold it down until the pic spits out then release it. I even used the battery compartment for the batterys. I currently am making a bracket to help it lock into the tripod socket on the kiev so it stays together and adding some foam to stop light leaks.