Metal Leg Part 1: Framework

From Iron Man to Terminator, pop culture has shown that robotics mimicking human motion are seriously cool. This project is a start on a robotic suit, the framework of a leg.

Supplies

3 galvanized steel angles, 1” x 6’
3/8” and 5/16” machine bolts and nuts
Tape measure
Reciprocating saw with metal cutting attachment
Hammer
Marker

Initial Measurements

First I measured sections to fit my leg sections; lowe leg, upper leg and waist. On the lower leg and the waist I left four extra inches for actuators later.

Making the First Cuts

As long as you have a lot of material, it’s best to cut generously and grind down any extra later.

Joints and Supports

For this early version, I elected to joint my “legs” using bolts. I used two nuts on each joint bolt to let the leg swing freely. In addition, support was added in the form of two cross-beams; one for the foot, and one for the upper leg. The upper leg beam was hammered down not only to keep it from colliding with the joint but to give extra torsional strength, and the foot support can help you balance on it as well! On a side note, make sure that you can use the joints. Sometimes extra material gets in the way, so the best way to deal with it is to grind off excess! Supports can also be welded for maximum strength.

Finishing the Frame

With everything bolted on, the leg frame is now complete! For testing the integrity of the frame, tying it to your leg seems to do the trick. The next project will be actuation!