Here it is in all it's spaghettiness sitting on it's unfinished barge.
Machinery deck layout. The lower left servo is boom hoist, center is swing, upper left is digging line, upper right is holding line and the tagline winder is on the far right.
The drums are turned out of acetal rod and the centers are bored out to .25". Then I cut the arms off spare servo horns, turned the hubs down to about .255 and pressed and superglued them in so the drums could be mounted on the servo spline. No problems so far.
Swing gear is done the same way as the drums even though it's aluminum. The swing circle is what I think is called double-row ball bearing. The outer piece has a flange on the inside, sort of a tee in cross section, with a ball race machined into both sides. Then upper and lower plates have matching races machined into them and sandwich the flange. Then screws go up through the lower plate, thread into the upper plate to hold it all together and then stick up about 1/4" so the machinery deck can drop over them and be fastened to the swing circle assembly with nuts. Hopefully that makes sense.
Tagline winder. The spring pulls the lever, lever pulls shaft, shaft spins drum, drum pulls bucket.
