Nuts and Volts - September 2014

the wheels of the Stingray robot. Subsequently, we had to fabricate our own crank arm and pulley assembly for these motors. To do this, we purchased some angled aluminum, a cable clamp set (Figure 5), and patio door wheels (Figure 6) at a local home improvement store.

To create the crank arms, we started by cutting the angled aluminum to a usable size (roughly 12 inches). We then placed the horseshoe bolt from the clamp set onto the crank arm and marked where the two holes would go.

We used a spring punch to create start points for the drill (Figure 7). After drilling the two holes, the horseshoe bolt is placed around the motor shaft (Figure 8A), the bolts are affixed to the other side, and tightened down (Figure 8B).

Make sure the flatted part of the motor shaft lays flush against the aluminum bar to ensure the crank arm doesn’t slip (Figure 9).

Next, we drilled a series of holes in the angled aluminum crank arm so we could select different travel distances for the anchor point. We then attached one of the patio door wheels to the end of the aluminum crank arm (Figures 10A and 10B).

Holes were drilled in the edge of the wheel to create points to which we could affix the strings (Figure 11).

Once we had both of the completed gearhead motor/crank shaft assemblies built, they were mounted with hose clamps to the tops of the stands holding the skeletons (Figures 12A and 12B).

You’ve Gotta Dance Like Nobody’s Watching!

The completed Trio de los Muertos works better than we could

58 September 2014

RESOURCES

Tamiya Gearbox with Crank www.pololu.com/product/67

Suggested Gearhead Motors All Electronics www.allelectronics.com/make- a-store/item/dcm-451/12vdc-60-rpm- gear-motor/ 1.html Electronic Goldmine www.goldmine-elec-products.com / prodinfo.asp?number=G17949

Marlin P Jones www.mpja.com/12VDC-68-RPM-Gearhead- Motor/productinfo/15870%20MD Video of the Trio de los Muertes Dancing www.youtube.com/professorconrad Marvin Niebuhr www.ProfessorConrad.com