So this week I had scheduled a serious push to really make some progress and I have been to the space every day of the week so far. Yesterday, unfortunately, I got a bit of a cold, so it looks like I will have to cut things short and work from home tomorrow. But I think I have all of the pieces that I needed from there, anyways. The first success of the week was when I, after a few failed attempts that were all my fault for not ensuring there was proper support, managed to dial in how to print the front cover.

So the Raspberry Pi Pico could not handle the flow of interrupts. So it is back to Arduino. Also, I realized that I can make the electronics slimmer if I solder the pins and remove the plastic bar. So this is basically back to what this looked like long back. But it is modular now and that will be such a relief. Motors work, but the encoder is misbehaving. Will have to figure that out.

So it seems that the 3D printer consistently prints about 0.1mm thicker than the design. Oh well, a bit of carving and some adjustments to the model for the next print and it should be fine.

So today I picked up the pieces. Lots and lots of support, yes. But after some effort, all of the support was gone. While I cleaned up the support, I made a simple mock of the center plate, just to get a feel for it. I went with a mesh patterns to reduce the ammount of material and time. But for some reason, Cura thought it should do each square invidivually rather than do an infill-stype cross pattern.

So back to the Makerspace for the first time in a while. The plan was to start a print of the mechanical parts and possibly experiment a bit with CNCing in plywood. The 3D print looks like it is off to a good start. I could only find a 0.6mm nozzle that wasn’t broken but that is close enough. As for the CNCing it seems that the router is still not done.

So a bit of experimentation with the modular motor controller gave some very promising results. So I have now orderd all of the material and hopefully I can now rebuild the model using the new and improved designs. And here we have the 3d-printed parts all set up in Cura Oh, and here is the motor driver module with all the cables for one motor.Way cleaner than the old design. Also, The Raspberry Pi Pico is a joy to work with.

A raspberry pi pico and a dual motor driver. Just connect USB and 12V and it should be able to control 2 legs…

So I was doing rather well on the algorithms. But then I wanted to check that all six legs worked well. Suddenly stuff started behaving strangely with motors and encoders not working. Probably some form of short circuit or something. I have had a hunch for a while that my design contained two many onprotected open wires that could lead to any and all forms of strange behaviour and busted components.

So after spending a whole lot of (Very enriching!) time building a dynamic system to be able to control the drivers and run test with configurable parameters over the serial, I realized that that was just completely hopeless on such a tiny device as the Arduino. With no dynamic memory to speak of, trying to build a flexible dynamic system is just doomed to fail. And then it hit me. I am trying to build testable code… and in extension a testable electro.

Yeah, so no visual update today. But now I am in the coding phase. So far, this is what I have gotten done: Homing code that can be run in the main loop as the Uno only has 2 hardware interrupts and I need 3 for each leg. A robust proportional regulator that runs the leg at a given speed. The static friction in the motors seems to be pretty high so they need a bit of a kick to get started.