When the idea of making a robot becomes a feeling and you say to yourself, “I feel like making a robot!”… well, that’s when you need to get on down to our super-secret robot makerspace and exercise that emotion. That’s precisely what we’ve been doing these past couple of Saturday mornings. In this blog post I’ll attempt to put some words to those glorious feelings.
It was a hard Saturday morning of flies, dust, stiff rawhide gloves and rusty metal as far as the eye could see. We had just arrived at the BIMCO scrap metal yard. Avi lifted heavy metal things and looked at them, Ian spent time with tires, Tiffany supervised and I tried without success to convince the metal crusher guy that his shift was over and it is now my turn to operate that wonderful machinery. He wasn’t having it. Anyway, we found metal, we found lots of it, we bought some of it and we brought it back to headquarters.
We don’t have a real plan for making our self balancing robot (aka. DIY Segway for under $400) so we just started putting objects near each other in a configuration that we imagine to be the robot we want to make. Voila! It looks good to us and we are that much closer to our goal.
The robot chassis not only needs to withstand the forces of the two 280 watt motors we bought on ebay ($32.99/each) but it also needs to safely hold up a person. We started with a couple of pieces of extruded aluminum square t-channel bolted together and then doubled up up on some 6.25mm scrap to make 12.5mm end pieces on which to attach our wheelbarrow wheels, which we secured with big bolts and washers.
It was unclear where to drill our bolt holes so we cut a few slivers from the extruded aluminum square t-channel so we could make a pattern. Then Avi ate some watermelon.
Ian dreamt up a super-cool custom collar to hold the sprocket to the wheel. He then machined that piece into reality. Oak ply was relatively cheap and easier to work with then the scrap iron we were using so we cut it to fit and bolted it in place.
I refashioned the end pieces where the wheels attach. The frame seems to be holding up nicely sitting 20mm lower than before.
Avi brought his ol’school cathode ray tube oscilloscope to test the h-bridge circuit he designed to run the motors. With some perfboard, an electomagic degree, and some parts he went to work. Like the wizard from Fantasia, a flurry of soldering strokes and mystical utterances brought forth a whole universe of circuitry wonder.
I mostly just made sure we had some nutritious snacks and that the shop music was partial to my liking. Well, I think that’s about it. We’ve been robot making for the past few Saturday mornings and I can honestly say, “It feels good!” Stay tuned for phase II of robot evolution happening in our temporary robot makerspace in the basement of some guy’s house.