..and while I'm here, have some some bits that might be relevant to your interests for some inspiration. These are prototypes of parts that were later refined and deployed elsewhere.
1) Servo bracket; Soldered aerosol can box with a steel wire bent to act as a retaining clip, can be soldered or screwed wherever needed.
2) Rotating platform; This ended up as a neck with a reduction gearbox on the platform engaging a ring gear on the brass shaft. Brass slides right into bearing nice and snugly, standardised sizes are your friend.
3) Leg for a biped; Mechanically it does the job but all shades of fail because I didn't leave room for servos and had no way to disassemble the ankle (because it was made before I started planning out jobs in sketchup ;) ), at it's core though it is all universal joints. Nut is soldered into the end of the brass retainer on the upper leg, nice snug fit of sections provides pivots for the "hip" section and the "pelvis". Note the lapped steel over the pivot on the top of the thigh, added to reinforce the small section of tube that forms the pivot to the end of the brass rod. Parts of this can easily be modified to become a steering control arm and other core suspension parts.
4) Bell cranks and lifters; Again, sliding fit of the tubing is utilised to create a crank, shaft goes through the central bar in the second part of my pic in
>>895424 and forms part of a servo driven lifting section. Long, M3 screws have their heads cut off, threaded section is then soldered into the end of the tube to allow the cranks to be bolted on (because again, standardised sizes, everything fits)
The reason I sing the praises of this method wherever I can is because standardisation, that is literally it. It is so damn simply to make components and pivots, all you need to do is learn to wrangle a soldering iron and you're in.
