Insentricity

Who wants a Coke?

I just got the two narrow slots working on my Pepsi machine. I fabricated the cams out of tempered hardboard. I used 3/16" not because I wanted it to be stronger but because I had small scraps if it around and I didn't feel like getting out an entire 4'x8' sheet of 1/8" and cutting off a piece.

The cam doesn't actually move any of the machinery, all it does is click the switches at the right time. Because of this I was able to make it out of wood. As it turned out, cutting the spurs was actually quite easy, once I made myself a circle cutting jig. All I had to do was use my bandsaw to cut out a circle at the radius of the spurs, then notch the spurs and cut a smaller radius so that the spurs were left behind.

Getting the relationship of the spurs to the rod was trickier, and required a bit of trial-and-error and I had to shift one of the spurs slightly and re-make the cams. Getting the screw holes in the right place was also tricky, but I used one of the existing cams to mark the position.

I think most of the work went into making the circle cutting jig. I had to make a jig that would let me slide it into the saw so that I could cut around the spurs. I also needed to have the pin completely adjustable so I could get the radius just right. I made the jig from some melamine and routed a long slot in it perpendicular to the blade. I cut a 3/4" wide slot 1/4" deep on the top and bottom, and a 1/2" wide slot through the center.

To keep the jig aligned with the table I put plywood runners that ride against the edge of the table. I didn't bother with making something ride in the miter slot. For a stop I just clamp something to the back of the table. I did it this way so that I could use different sized blades and always be able to make sure the jig would line up with the leading edge of the blade.

For the pin I drove a finish nail through a 3/4"x1/4" piece of scrap, stuck another scrap the same size on the bottom, and drove a 5/8" wood screw down from the top. This lets me loosen the screw, slide the pin where I want and then tighten it from the top without having to move the jig. If I were to make it again I might do it a little bit different, but this works really well and will likely last a long time.

Oh, and in case you're wondering why I said "Coke" in the title and not "Pepsi," it's because I put the Coke in one of the narrow slots.

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