I was on a roll this weekend and have some photos of my progress to share.
This first photos shows how I printed templates for my motor mounts. I first cut the mounts to their final width and height, glued them together with wood glue (tried spay adhesive first but it was too messy), glued the template on, marked the holes with a center punch, and drilled the mounting and clearance holes on my drill press. The photo below is my first design. Taking a page from my RC airplane days of constructing planes from foam, I added tabs and slots.
Note: I originally drilled the holes the same for both side, but due to the motor shaft being offset it was not symmetric like the encoders. Also, the mounting hole closest to the output shaft is too shallow for the screws I had. What is, was symmetric are the two mounting holes at 180 degrees which is what I am using.
The second image shows the motor and encoder mounted along with the gears and wheel. The motors are heavy and the assembly feels like it weighs half a pound or more (will measure it and update this post).
To add the mounts again I when with a tab-slot design. I printed a template for the base to locate the slots and used a razor knife to cut them out. I also had to make slots for the small portion of wheel that protrudes through the base.
Next steps are to:
- Strengthen and square the mounts using l-brackets and a cross bar of some sort. I have some acrylic rod I am going to try. Failing that, I’ll add a skin of 3mm PVC along the bottom to tie them together.
- I have decided to redo my motor controller board using the ribbon cable wires versus wire wrap. The insulation is better, and I had an issue with intermittent shorts when I tested it before.
- Create the cables for the encoders to the interface board
- Make some mounts for the caster wheels (it’s really back heavy right now so 1 may be enough)
- Write some code to drive in a square
Onward,
Jay
