dog exercise wheel

  Figuring out the geometry and marking out the cuts to be made was one interesting aspect of this project.  I made use of laser-printed paper "protractors" in several steps of the construction, particularly one consisting of two lines forming a 60-degree angle, taking up as much of the 8.5x11 inch page as possible for maximum precision. I used a flat board as a "compass", slightly longer than 3 feet, with two holes drilled, one for a screw at the central pivot point, and one for a Sharpie marker at the radius point. The curvature radius of the outer and inner edges of the rim pieces should of course be slightly different, but I glossed over this and made both radii the same.  Thus, the pieces would nest together as seen in the marked-up plywood sheet above, and there were fewer curved cuts to make with the jigsaw.  I made the curvature correct for the outer edge, so that the wheel would roll smoothly on the floor when being moved about.  The curvature of the in...

Our sweet little McNab dog, Willie, is 6 months old now.  What a great dog -- but she is a handful!  Never-ending need for action.  So we thought we'd try building one of these dog exercise wheels.  Basically, a giant hamster wheel.  There are lots of videos on youtube, showing different hand-built and storebought wheels.  Some dogs take to them, others don't.  The cost of manufactured wheels is ridiculous, like most pet stuff, and our requirements are quite specific, so it seemed like building from scratch was the best option.  However, this meant that we wouldn't really know if the wheel was a success, or a big waste of time and materials, until the whole thing was built and functional.  No way to incrementally test as we go. I wanted to make the wheel just about as big as possible, while still fitting vertically in our basement with fairly low ceilings.  So I went for approximately a 6-foot diameter.  The wheel rides in a support...