I'm making some progress on the final "DiggerBot" parts. Here is how I made the bucket and arms.
I used the flat bucket shape from the prototype model as a template, then traced it onto a piece of 2"x4". I added a bit of length to the front of the bucket for the "teeth". Then cut it out with my band saw, and sanded it smooth on a belt sander.
Next I cut out the sides of the bucket from some bass wood, then glued them onto the bucket.
I had to modify the bucket a bit to allow for the full range of motion when connected to the arms. I had not accounted for this problem with the flat bucket model. So I cut out a section, then glued on a little extension, drilled it and sanded to the circular shape.
Here's how I made the "couplings" that go on the dowels for the arms. You may note that nothing is exactly squared-up and precise. I don't think I can do that if I tried...I definitely show the "hand of the artist" on these projects. Adding the paint job at the end hides a lot of those imperfections.
Here is how this new bucket will move. The lower arm is probably going to look different than what is shown here, but you get the basic idea.