scout updates: making the center frame [updates]
So today evening, while waiting to go on a walk with a friend, I'm going to laser cut the pieces for the scout's main central electronics frame. We're using a Dremel Digilab Laser Cutter because that's the most easily available one. Using SHAPER plugin for Fusion 360, we exported all of the pieces we made yesterday as SVGs, and laid them out in Digilab software.
We imported the SVGs into the laser cutter software, laid them out, and cut it out of 1/8" thick birch plywood. It took two cuts because of the number of parts and the fact that the bed of the Laser Cutter is 12"x24". Now we wait for the parts to come out... in the meantime (as is good practice) WATCH THE LASER CUTTER SO IT DOESN'T SET FIRE TO ITSELF.
Okay so we actually have to do this in four cuts hehe oops. But either way we can start assembling!
We start by gluing together that first bottom box, the four supporting walls first, let them sit for a few minutes until they mostly harden, and then it's time for the top which we will glue then clamp.
Okay so I finished building the thing, it looked lovely, and then I went to put it on the robot. Most of me was clearly stupid when I designed this thing because the outer wings holding the motor controller spread themselves over 1.5 times the width of the body. How'd I manage to do that who even knows.
Therefore, the final electronics box now looks like this:
Now what we're going to do is mount most of the electronics to the box but not the Jetson as we still need to do much work on that controller. First we start by taking the power distribution panel and zip-tying it to the lower panel of the box we've created. The top surface will be a mounting location for all the motor controllers. Extra space will be added later for the Jetson controller.
Then we are going to lay-out the motor controllers on the top surface so we might get an idea of how to mount them. The picture below show the layout for 6 of the motor controllers. It seems easiest to lay them out in this way with the ones with the longest wires farther from the power distribution panel and in a grid system like shown.
Now we are going to start mounting them with 3M Double Sided Tape in exactly the fashion shown above. The only difference is they'll be attached to the board. After this we will do some cable management and labeling of motor controllers. The controllers will have a number which will also be their CAN ID (when we get to that).
Nice clean layout of the motor controllers :) In fact, the wire sizings worked perfectly as well! We have not wired in the controls system yet, and we won't yet, nor do we have the crimp connectors to connect the motors to the controllers, but the motor controllers closest to the front and back of the body will be for the knee joints, the middle for the rotating shoulder joints and the closest to the center of the body for the body-mounted shoulder joints. So we will wire in the encoders right now. Those are done being wired in - let's call it a night!
The encoder wiring plan above worked for the first three legs, except for the right-front leg where the motor mounted on the body, the wire was too short to reach the central-most motor controller, it was instead plugged in to the forward-most motor controller. This doesn't affect anything because we are planning to use CAN and we can change the CAN ID of any motor controller to anything. We'll just note this issue and remember it in programming.