I am still working on my Tiny24hourMobot, which as the Question of Scale Project14 has finished I will now call TinyMoBot. As I do not yet have the smaller parts needed to make TinyMoBot fit inside the spray can lid I thought I would look at slightly larger alternatives. For Christmas decorations (the Merry Boxes and LEDs Challenge) I purchased some small glass cloches, although I never used them. I came upon one recently and realised that it was about the same size as the spray can lid I have been working with, but a bit taller and that it might be a good candidate for the shell of TinyMoBot. Being a pre-existing part it did not have any fixing holes such as the 3D shell I printed for Tiny24hourMoBot so I thought it might be fun to 3D print a structure containing the two servo motors which the glass shell could just be dropped onto. The simplest structure seemed to be two flat circles separated by some metal spacers I had recently purchased. The bottom one could be fixed to the structure of the two servo motors with self-tapping screws and the glass shell would rest against the top circle. I printed the two circles, added the spacers, connected this structure to the motor unit and amazingly it worked out quite well. I have 10 mm spacers and needed about 25 mm so I added some nuts to the thread part of the spacers and it was just about perfect. From looking at the existing Nano controller it did seem that it might also fit inside, so with a bit of careful manipulation (i.e. I just jammed everything in) it all went together nicely, see photograph below.
Obviously the battery is not yet inside the shell but I used some connecting wires to connect to the external battery pack and surprisingly it still worked, see the video below.
After this great triumph I think I will have to wait now until the parts for the smaller controller and LiPo battery booster to come and then there is the great possibility that I might be able to create a completely self-contained TinyMoBot. There is also the added advantage that because the shell is glass I should be able to use optical sensors and perhaps LED just for a bit of interest, all integrated into the internal body structure and not have to do anything to the glass shell itself. Then I just have to make several more and I will have a swarm!