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Comment by rfrey | Hacker News Reader

Nowadays if somebody wants to build a machine without a lot of tools available, and doesn't have the goal of recreating industrial revolution processes, I'd recommend looking into epoxy granite casting. Epoxy granite will result in a way better machine since it has vibration damping qualities similar to cast iron. It also avoids melting metal, which everyone can do but some might want to avoid.

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For anyone interested there's a wealth of epoxy granite info on the CNC Zone forum.

https://www.cnczone.com/forums/epoxy-granite/

I was about to recommend the exact same thing. Epoxy granite is used by some world class machine tool builders.

I think an interesting modern take on the Gingery machine, would be a homebuilt machine tool; built from epoxy-concrete. Linear rails, servos, fly-by-wire controls with force feedback.

Machine form factor would be a la Mazak Integrex but much smaller and fits in a two car garage. Total envelope would be 8"x8"x8"; high spindle speeds w/ low depth of cuts. That should compensate for the total lack of stiffness :)

There are several people who have documented builds of epoxy granite mills. Much bigger than what you described generally, but still garage machines. https://www.youtube.com/channel/UCIuvJtM342E7p2nEpwTGbDw and https://www.youtube.com/channel/UCssIc2lLpX1nIHkymAzEptw are two of my favourites.

I'd really like epoxy granite linear rails for the noise dampening attributes. If they're flexy they could just be bolted to a metal or wooden support.

What do you mean by fly-by-wire controls? Just manual jogging with CNC controls or do you mean something more specific?

Exactly like jogging with CNC controls; but with force feedback. I have done some cuts with the Haas in handjog mode. I always feel iffy doing it, since I can't feel the feedback from the cutting forces.

That sounds awesome. Do you know of any builds that have done that?

Pointers would be much appreciated.

Actually, you are almost always better off buying the Chinese-import machine tools. With a bit of scraping and adjustment, the Chinese imports can perform extremely well.

The main thing about the small epoxy granite milling machines is that they have stupidly (30K RPM+) fast spindles--and generally have through coolant/air. That way, the cutting edge removes material before significant lateral forces develop and compromise accuracy due to lack of rigidity.

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