10 February 2011

Jetta update

Haven't posted in a while but I've been busy on the Jetta. Lemontree helped me put the engine in, so I've been busy hooking things up to it. And since I already had the dash apart anyway, I went ahead and did the heater core too since it's a right pain to get to.

Anyway, since I've gone the do-it-better-than-the-factory-did route for the alternator mounting, I need a tensioner pulley for the alternator belt. I got started making it but had more and more trouble until I realized I had to take my lathe all apart and adjust it again. Since I didn't really know what I was doing the first time, I didn't really adjust it right to begin with and then actually using it made things loosen up and move so it was time to start over with the carriage, cross slide, and compound adjustments. I also switched to a different type of cutting tool as the $5 Harbor Freight junk is, well, junk. That all done, I was able to make this:

That's several ounces of aluminum "chips", though aluminum makes such long stringy chips the phrase "bird's nest" comes to mind as a more appropriate name than "chips".

Here's the half-completed alternator pulley:

This 3" aluminum stock is about as big as my largest chuck can handle (definitely too big for the chuck that comes with the lathe). Though aluminum, it's still quite heavy for something going to be spinning 15,000RPM which is why I'm hollowing it out and will follow that with drilling some holes to lighten it further (and make it look cooler).

While I was making lathe improvements, I made a second chuck key for my 4-jaw chuck. Unlike a drill chuck which automatically centers the drill bit, each of the 4 jaws is independent so you can grip irregularly shaped pieces. This also means centering something round is done manually by the machinist one jaw at a time... or better, 2 opposing jaws at a time, which is why I made the second chuck key:

The left key is the one I made and the right key is the one that came with the chuck. By turning them together, I can shift the work piece left or right and that dial you see will tell me when I am centered (then I rotate the work 90° and do it again for the other set of jaws). At first I had tried it with just a single key and it's a real pain since the normal key is short and hits the dial indicator and you have to keep turning the work 180° and measuring again. That's why I made my key really really long so it would stick out beyond the dial without hitting it -- clever, no?

I had a hard time soldering the handle on my second key, too. I swear I am cursed when it comes to joining metal... I love cutting it but I sure hate getting it to stick together.

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