Part two by Alberto Celot

The first problem I decided to tackle was that of the Main Engine. After several attempts to adjust the size of the various parts in the CAD simulator, I realized the extreme difficulty of finding a good compromise that assured me a proper rotation function, both clockwise and counterclockwise. In practice, the motor normally operates with a clockwise rotation that corresponds to the lifting of the bucket; for lowering the engine is stopped, the clutch is controlled by RAM cylinder is disengaged and control is through the brake drum. The counterclockwise rotation of the motor is only used during the travel command via the tracks, and lifting/lowering of the arm through the winch drum. The rotation can then be optimized in a clockwise direction, but there has to be a good counter-clockwise rotation, too. 
My son Roberto came to the rescue with a program  to resolve the issue. All measures have been parameterized, allowing to vary during operation and checking the effect on the oval diagram which provides the position of the slide valve according to the position of the piston. With this system I was able to find an acceptable solution in a short time.
Below is a picture of the simulator:
When the correct dimensions were set, the various components were drawn in CAD and checked with assembly drawings. 
The complete engine comprises two engines, in a mirror-like design, placed one on the right side and one on the left side of the cabin. The following figure refers to the right engine (the long axis protruding serves to transmit the reverse command to the other engine):
The design continued with the Swinging and Thrusting engines.
Basically this is the same engine with double cylinder variation only of the crankshaft and the joystick.
Below are two images of assemblies of the two motors, the first is the Swinging while the second is the Thrusting:
I finished the design of the machinery mounted on the main frame (Revolving Frame), comprising: 
the Main Engine that drives: 
-via a steam clutch, the drum where the steel rope, that raises the dipper, is wound 
-via a dog clutch, the drum of the worm gear winch that raises and lowers the boom 
-via a dog clutch, the transmission of motion to the axis coaxial with the centre of 
rotation, that controls the translation through the tracks 
the Swinging Engine that drives the rotation of the Revolving Frame »the foot-brake pedal that locks the hoist drum of the dipper 
the foot control valve to send the steam to the cylinder, located on the boom, which controls the opening of the door of the dipper 
Below you can see the pictures of the overall assembly 
The area in the back in the first image is the location for the boiler. The lower part of the frame will be completed with the insertion of the side members and other reinforcement to reproduce the original frame casting. 
In the second image, the larger gear is the steam clutch, of which you see the control cylinder and part of the control levers mounted on gear itself In front of the operator's seat you can see the two levers which control the Swinging and Thrusting engines, while to the left of the seat there is the lever that, rotated at 180°, provides the reverse of the Main Engine. To the right of the seat, you can see the two levers for the insertion of the dog clutches for the winch for raising and lowering of the boom and for the motion through the tracks. 
The third and fourth images show the winch and more general details. The A-frames support the pulleys for returning and anchoring the steel ropes.
The design continued with the lower part of the revolving frame, comprising the conical rollers on which the frame rotates. Rotation is provided by a pinion which meshes the large gear placed on the fixed part below.
Part one   part two   part three   part four   part five  part six  part seven  Part eight
part nine   part ten   part eleven  part twelve  Conclusion