Chopper's Legs

CNC Design

Chopper's Right & Left Legs are derived from Cleofett's .dwg drawing files. See the Legs  page for an interference problem between the Leg and the Foot shell and the solution that I have adopted here.

Left Leg
Right Leg
At first glance, Left and Right Legs look like they might require two different designs. The Legs, however, share a lot of details in common. The most obvious parts that are different are the top portion of the two legs and the detail attachments that mount on the front surfaces.

Right Leg - common Leg Frame with a non structural CNC assembly for the upper portion. Note: while there is a seam showing where the two pieces meet, the skins will be full height for the Right Leg.

Right Leg - shown with Applique removed. #10 washers go in the 3 recesses to give the magnets on the Applique an anchor point.

Left Leg - common Leg Frame with a casting for the curved upper portion

Left Leg - shown with Applique removed. The 2 thru holes (where magnets go for Right Leg) match holes in the Applique. Put pieces of 3d printing filament in the holes for alignment,

Common Leg Frame.

The remaining (older) drawings show the internal structure.

Leg Frame design is a structural component common to both legs. In this image it's wrapped with .040 skins (2 layers on the curved top portion).

Here we have peeled off the .040 skins. The blue color components are .125 thick non-structural parts of the design. The balance of the parts are all .1875

For strength, the leg has 3 layers of .1875 styrene, with an additional layer in the area where the leg bolts to the body. As a result of the change in thickness of the leg where it is mounted to the foot, there are 2 layers in the top inner section and 2 layers in the bottom outer section of the leg.

With the outer layer peeled off you can see the box beam ribs that run top to bottom as well as ribs that radiate around the area where the leg bolts to the body. The center channel between the shoulder and the foot is unobstructed for wiring between the body and the foot. Not shown is the hole at the bottom of the legs for the wires to exit. It's location is dependent on which side of the body the leg is built for.
What's still to be done: It's my first pass at designing parts to be cast. More than likely I've done some things that will make casting the parts more difficult. I'm waiting to get feedback on the parts I'm proposing to have made,
Design 'cleanup' - the bevel edges on most of the parts that have them are cut to the angles dictated by the design. Bevel cutters are restricted to the available set of 15,30,45 degree angles. The bevels will be modified so that the edges meet where needed.

Please ask questions,  make comments & suggestions that you think might improve the design.
Contact me using: fpirz (at) media (dash) conversions (dot) net

All designs are copyright Media-Conversions LLC and are made available for non-commercial use only.

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