Ben and Jerry are two new characters for this third automaton, young competitive brothers going head to head at the Gymnasium. A simple set of cams to drive the right arm into a punch, with a wire attached to the forearm to move it straight to the Punchball.
Each brother taking it, in turn, to hit the Punchball, with the timing being controlled by swivel plate mounted in the centre of the camshaft.
Construction is straightforward, guided by the drawings shown here. The motion is geared down three to one to slow the motions as they seemed all a little quick when driven directly.
For more models to print, including several working clocks go to https://www.3dprinterclocks.com/page26.html
You will need 1 of each STL part except for the following:-
Arm upper LH 2
Arm upper RH 2
Arm Lower LH 2
Arm Lower RH 2
Hand Boxing LH 2
Hand Boxing RH 2
Arm Pivot 2
Arm Cam 2
Arm Follower 2
Shoe Pivoting 2
Body top 2
Punchball Cam half 2
You will need some extra components to complete the build:-
A PDF files showing the dimensions of these parts can be
1 piece Ø 3 mm steel rod 160 mm long
1 piece Ø 3 mm steel rod 27 mm long
4 piece Ø 2 mm steel rod 8 mm long
1 piece Ø 2 mm steel rod 10 mm long
4 piece Ø 2 mm steel rod 20 mm long
Ø1 mm soft wire (paper clip) for the Lifting Pin in the Shoulder and the Actuating wire for the arms
Acetone to solvent bond some of the parts together.
Drills Ø2 mm and Ø3 mm for the holes that need to be a tight fit.
Drills Ø2.2 mm and Ø3.2 mm for the holes that need to be a loose fit.