1/29/09 Vicki and I decided to build a pedal powered walking bicycle. Can't really remember what caused our irrational thinking that day. We were heavily influenced by the Mondo Spider and Walking beast at Burning man. I believe we thought no one had built a successful walking peddle powered vehicle before and I figured it should only cost two to three thousand in materials.
   1/31/09 I Submitted a proposal to Burning Man for the Spider bike to see if we could get a grant and with a month received a nice form letter saying how they thought my idea was very creative, Mr. "Insert Your Name Here." We went ahead and ordered the first wave of materials.

3 MPH. 1.2 revolutions per sec.with 2 legs

5.4mph with three legs, I think.

About that time I was lucky enough to contact Joe Klann by email. He's the inventor of the leg mechanism and he generously shared a spreadsheet which calculates the leg dimensions from six variables. His web site is mechanicalspider.com.

One of the problems with the other walking designs using this mechanism is that the upper and lower arms reach an angle that is almost parallel to the connecting rod. The mechanism then requires a great deal of energy to get passed that almost locked position. We picked a configuration that didn't have that problem.
I was thinking 12" stride at first but we went with 22" finally.

Turns out Joe had built a human powered spider bike a few years before out of 450 lbs of steel. He said it was too hard to pedal. He gave it to a friend of his in whose garage it still sits.

2/8/09 : 3/4" Thoughts on steel frame with aluminum legs and bushing pivots on the steel.

This one has nicer looking geometry, I think. 2/8/09

Also the Upper and Lower Arms are close to 90 degrees to the connecting rod and leg and so have less tendency to lock.

2/21/09 -Still waiting for parts. Made the drawing at left. The thing seems to be too complicated to draw completely.

(That is a very creative idea for a walking machine, Mr. "Insert Your Name Here."

   March 1: Here's what has been happening. Axle bolts through the bushings seemed too expensive so I bought machined rod for about $35 for 12 feet. But we couldn't get the bushings to line up well enough for the machined rod, except on the first tube.
    I made a steady rest out of shower door rollers and scrap. But even so, the machined rod requires nearly perfect alignment. Now we have about five done but we are out of bushings, because we ruined so many.
   We cut some of the machined rod to use on the plywood template and we tried threading one end of the rod to bolt it to the plywood at the pivot points. We couldn't get the die to cut straight.
   So we went to Orchard and they had 3/4" x 6" bolts there for $2.79 each. They are slightly smaller and go right through the bushings, which the machined rod won't. We should have done that right in the beginning.
   So after one week, we have almost five tubes with bushings on bolts with channel holders. We need 54.
   At right is the plywood pattern with bolts installed and leg tubes cut and top arm and bottom arm ready for fitting. The foot is welded to the bearing which caught fire but seems okay for running. We did most of this last night. It's going to be a lot of work which will cut into our TV watching, but it doesn't seem impossible. Everyone keeps saying the bike is too complicated and that I am not normal, but, it's not me. It's Vicki.

I used magnets and aligned everything by eye. It looks pretty parallel and straight and operates smoothly.

Next is to connect the legs and see if it walks as well as the first set. Then we get to make the frame and seats and so forth. i am thinking a wheel or two in the back for now.