Building a New Lathe

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vtsteam:
Since there's no draft, only the wiggling allows the pattern to be removed. But because on a narrow part like this, there is little circumference, there is also reduced drag compared to something more massive.

Here I've finished withdrawing patterns, and as an experiment I also made a pouring basin and runners (channels). I was thinking this might trap impurities and reduce the chance that I would collapse the part hollows by pouring directly into them. In the past with a single part, I just poured directly -- with good results. But this time I wanted to try something slightly more sophisticated.

vtsteam:
I'd started the furnace when I started molding. It was ready when I was.

The pour w/ Zamak12. It starts out shiny as mercury. Total molding and melt time: 20 minutes.:

vtsteam:
And in an other 20 minutes it looks like this. There is a typical hexagonal crystalization barely noticeable. Minor shrinkage (mainly due to the small volume of the parts.)

vtsteam:
This is the shakeout immediately after the last pic.

I took file to the top and bottom, then took 3 thou off of both on the mill. The upper piece has been rough filed, the lower skimmed on the mill. The tops will be final milled once attached to the cross slide so they end up flat and even.

Here's the skimmed piece with the wooden pattern that made it. Notice how closely the dimensions match the original pattern. Wiggling the patterns in the mould increased the cavity size by a tiny amount, but shrinkage and filing flat compensated, so the pieces have near identical sections..

Total time from concept, cutting rough stock for 16 patterns, sanding and finishing 4 of them, molding 2 of them, melting metal, casting, cooling and having in hand metal parts was 1 hour and 20 minutes.

I don't know of any pop-tech method that could compete for speed cost or simplicity or conservative use of materials and fuels than ordinary direct pattern making and casting.

I'm not trying to prove that one way is "better" than another, because this is all hobby stuff, and the interest and challenge are the most important products, not the objects we produce. But I do want people to understand the reasons for my personal choices -- many younger people do not actually understand them.

I do it this way because it gives me great joy to move that fast, that directly, and that easily from what I conceive, to what is there, ready to use. That personal choice comes from my own love of traditional skills and efficiencies. There is no intervening program, or computer or robotic tool. It's just me. That's my gas.

vtsteam:
And the same section we started with in metal:

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