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Saturday, July 30, 2011


None of the lathes I have access to on the weekends have chuck jaws long enough to hold the scooter wheels I bought. They just pop out when I try to tighten the jaws. The wheels are only 1 inch wide, but they're 4.9" in diameter, so I have to grip them by the reversed side of the jaws, which are <1/2" on most lathes. The Edgerton Shop has some chucks that would work, but it was closed the only Saturday this summer I needed to use it...go figure, right?
Next thing I tried was the laser cutter. My plan was to cut out a hole for the wheel in a piece of plywood, then set the wheel in it, and cut the ID I needed. Well, it was sucking particularly bad today. In the past, I was able to cut through 1/2" plywood in one pass (nice plywood, too). This time I couldn't even cut through 1/4" shitty plywood in one pass. And yes, I cleaned both mirrors and the lenses. So I have no idea what's wrong with it. And as you can imagine, the wheel didn't get perfectly lined up, so when the laser went over it the first time, it didn't cut a concentric circle, so I gave up on that method.
I also maybe could have cut it out on a mill. But (yet another but) the MITERs mill vise only opens to 5", so I couldn't use angle blocks, so I'd have to make some sort of jig. It would probably end up being about as accurate as the laser all said and not worth it at all.
So I went on a hunt for some 4.9in pipe to press the wheel into while I clamp the pipe in the jaws. Turns out you just can't find the stuff. PVC is made in 4" and 6" (I found plenty of both of those). Even Mcmaster doesn't carry plastic pipe 4 7/8" ID (well, they have acrylic...but that's useless because it'll just break). So I would have to buy some undersized pipe, turn it out to the right ID, then press a wheel in, bore it out, take it out, press a new wheel in, etc...huge pain in the ass.

So, four fails later, I'm just going to listen to the MechE gods and give up. I'll take a few hours off of work this week and go and use the Edgerton lathes.

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