Maker Bot
A robot that makes more robots.
Concept
Again this wasn't my idea, although in retrospect it seems like like it was bound to happen eventually. This had me very interested for testing out two things: making a miniaturized robot (the one sitting on the table) to see if scaling down the whole thing was viable; using a "programming wheel" to make more complex sequences of movements. The new mechanism ended up bringing many difficulties though...
Construction
The first thing I did on this one was the the worm drive mechanism, which comprises the botton wheel (with a spring coiled around it) and the crank. All of the rest was pretty much built around it because I wasn't able to plan the full mechanism in advance. That's why several parts ended up being messy and all over the place. Some decisions were also made on the fly depending on what I felt was easier (for example the number of times the robot uses the pliers and how long the mini-robot keeps his arms up).
Aside from that, the mini-bot was also a bit dificult to make because the mechanism had just enough room to fit in the body. Again, that took quite some tweaking and I ended up building the rest of the body around the mechanism again. That's why the head of the mini-bot is placed a bit awkwardly.
New things
I tried quite a lot of new stuff on this robot. Maybe even too many, as I almost gave up in the process of making it. In the end I learned quite a bit though:
- Worm drive mechanism: this mechanism allows for much more complex movement. You could even use it to tell a short story if you do it right.
- Several levers can be driven by the main gear: each lever is activated successively when the wheel turns and then falls back into place. I tried out different types of levers. For example the lever for the pliers can be activated several times.
- The robot's neck is articulated: even though it can only move left and right, it's the first time I passed a mechanism through the robot's body.
- Scaling down the robot worked pretty well for a first try: the mechanism to raise his arms also worked out okay. It might be possible to make more complex miniature robots using thinner wire.
What needs improvement
As always, when trying out new things the results are bound to be a little unpredictable. Here are the main points that could make it better:
- Plan out the mechanism better: now that I know what worked and what didn't, I can plan out better for next time I use a worm drive mechanism. This will reduce the clutter of levers and wires.
- The main gear is too loose: the crank isn't tightly fitted to the gear, so whenever the gear gets stuck, the crank axis just jumps over some of the gear's teeth.
- The levers are too loose: they don't fall back into place very consistently. For example the head's resting position isn't very stable.
- The lever to actuate the mini-robot's arm doesn't work great. I made it kind of wavy so that the arms would move up and down several times but in the end it just served to get the gear stuck from time to time.
- Crank too low: in my hurry to make the mechanism I managed to set the crank so low that you can't turn it when the bottom plate is placed flat on a table.
- Need to avoid using shapeless props: I wanted to have the robot cutting a random piece of metal (the same way I make them) but this piece ended up looking pretty confusing visually. It seems better to use more recognisable props.
- Longer mechanisms can get boring: this one isn't as fun to crank as the others because most of the time nothing is happening. Next time I make a worm drive, it would be better to add a second mechanism that constantly moves.
Videos and more pictures
This one needed many videos and picture because it's hard to see what's going on.
