This evening it hit me around 7pm that I needed to do something constructive... I Wanted to go to Ace to grab some barstock, but it was already dusk and I don't feel like riding my bike at that hour. So I went to the basement and wandered around lookin' for stuff to do. Then I remembered about that broken drill press vise. Your standard China-stan POS (actually, Taiwan to be specific), it broke while I was impact-testing a piece of zinc-aluminum alloy. I'll admit that's not its intended use, ;) but still, the broken edges show a *lot* to be desired. The grain on this stuff is huge! If it was supposed to be grey iron, well, they should've tried a bit harder. Anyway, enough bitchin' about bottom-of-the-barrel, what-do-you-expect-edness, let's get on with it.
So here's how it broke. I've already stripped it of the jaw pads, sliding jaw and leadscrew.
Sorry, no pictures of the molding. Suffice it to say it wasn't anything unusual, except I filled in the fixed jaw to make it nice and heavy (not like aluminum will be any good for pounding on anyway though). Anyway, this is the crappy picture the camera took. Guess I should've got a bit closer to improve contrast. Right here the metal is all melted and quickly coming up to pouring temp. This propane is nice, heats very quickly!
Here's the mold after pouring. The large one is a 1 1/4" dia. sprue, smaller is the 7/8" riser. I vouched for an extra since the block the leadscrew mounts in is pretty heavy, and is at the other end from the sprue, which itself has to feed the fixed jaw part.
Back in the basement, after the metal cooled. (Still pretty hot, just below glowing heat so I know it's solid.. but I don't care, that's what running water is for!) So far it looks like it came out good... I was gritting my teeth slightly because the sand was pretty moist and I forgot to vent the mold.(!)
And it did work perfectly! Minus the sand's rough finish of course.
Even the marks from misguided drills, hammers and saws are visible. ;-)
Some hacksaw work, filing, sanding, scraping (that'll be a new experience for me), drilling, tapping and a coat of paint and she'll be ready for a few years of service! I say a few because knowing me, I'll just break it the same way as the original...