As promised in the introduction, I’m going to provide drawings that should let you build your own version of Pegleg or possibly be inspired to build something different. The first version was built with only a Dremel tool and drill, but the later version was machined using a milling machine and lathe. I recommend the latter, and if you somehow have access to a water-jet or rapid-prototyping machine (3D printer) even better.
Unknown Swedish tools
Advanced tools
Basic tools
Listed below are the prints and material list that should allow you to build your own hexapod. If you actually know a good bit about CAD, you’ll notice there are some format errors – please excuse them as I was still in school when they were drawn. Also, polycarbonate and acrylic under such trade names as Palsun, Lexan, or any number of other names are interchangeable for this application. (Their properties are quite different, but we’re not coming anywhere close to the limit of either). So here are the prints, assemblies first, followed by detail prints.
Assembled robot 2D view
Assembled robot 3D view
Main body pieces for this robot - External radii are optional as well as tapped holes around top center cutout. Center cutout on bottom may have to be modified depending on servo selected. Also 1/8 inch material is fine, .115 is the actual thickness of the material used. 1 of each needed.
Middle and front/back legs. 1/4 in radii optional. Quantity as shown.
middle bearing surface - 4 needed, originally constructed from acrylic.
pivots - quantity as shown. Could use dowel pins or metal stock. If you have no lathe, 8 - 32 screws will work but expect them to unscrew.
PURCHASED BILL OF MATERIALS (BOM)
(item – # needed – recommended supplier if any)
- 4-40 threaded ball linkages with 3/16″ ball 12 servocity
- Hitec HS-300 standard servos 2 servocity
- Hitec HS-605BB Super touque servo 1 servocity
- 4-40 threaded full thread rod (1 ft lenghts) 3 servocity
- 8-32 x 1 1/4″ Hex screws 6 McMaster-Carr
- 8-32 x 1/2” Hex screws 16 McMaster-Carr
- 4-40 x 1/2″ Hex screws 4 McMaster-Carr
- Basic stamp II processor 1
- Basic stamp Board of Eduaction 1
- Small cable ties ?
- 9 volt DC battery and connector 1
- AA battery and holder 4
- sheet of 1/8 in polycarbonate or similar material 1 freckleface.com
- piece of 1/2 in polycarbonate or similar material 1 freckleface.com
- 1/4 inch diameter rod or dowel pins for pivots 6
Some notes on the materials:
- Low head screws were used for the 1/2 inch 8-32 screws. Standard screws would work, but I think these look better here. Also, hex screws generally look better in my opinion, but regular (Phillips or flat head) will work.
- Basic stamp – Google or Bing would work for a supplier of these
- Allelectronics.com is good for the small parts like wires, battery holders, and stuff like that. But if you’re in a pinch, Radio Shack usually has what you need for a higher price.
- freckleface.com seems to be the cheapest supplier of plastic-type material on the internet. Watch out though, as their standard tolerances are +- 1/4 inch. They do mean this. Also, you can find this stuff sometimes at your local hardware store, but they may only have the thinner stuff.
So have fun building, modifying, and designing your own robot. Let me know if you actually build one. If you want to publish it, I’d be happy to host it here or link up to your site.
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