Industrial grade CNC router (that can mill steel) with concrete

Hi friend, this is probably the most ambitious project I've tried - certainly the biggest tool I've made.

It has an 8x4 ft bed to do sheet goods and almost 1.5ft of z travel to fit in big parts, and is rigid enough to handle steel (and aluminium is easy :cool: )
Wasn't simple or easy, for me at least, I was starting from zero with this CNC jazz - had no experience with using CNCs let alone building them. Plus I didn't want to go the usual t-slot extrusion route and keep costs very low. So yeah, a big learning experience which I hopefully captured some of, in this ridiculously condensed vid of the build process.

https://youtu.be/cqYJS27aC4w

You eloquently echo my own feelings regarding the lack of suitability of the T-slot aluminium extrusions for such projects. I have also used concrete in some machine projects, both to add mass and damping.
Great job. It is hard to get machine tool level degrees of stiffness on such large structures but you seem to have succeeded well.
Judging by the motor noise I guess (but may be wrong) that you are using conventional steppers. If so I would suggest looking at feedback or closed loop steppers. The difference is huge, I found this out when I once had a driver with the feedback switched off accidentally. Nowadays the price difference is small.

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Thanks bongodrummer! We've added your CNC Router to our CNC category,
as well as to your builder page: bongodrummer's Homemade Tools. Your receipt:

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Hey Tony, thanks! Yeah, as you said, it is difficult to get good stiffness over such a large range of travel. The machine's certainly not churning out hardened steel parts or taking big cuts at slow rpms in steel, but for the occasional prototyping part and the kind of tinkering stuff we do, it should work out well.
It is actually running Samsung AC servos, so yeah, closed-loop all the way :D
Thanks again, Bongo.

I can see A lot of time and effort went into your project, and it looks like it should serve you well.
Great job.