Concrete base for small mill?

I have not done this, but have thought about it. If I ever get around to it, I intend to use a fairly heavy piece of steel for the surface the machine mounts to. Heavy being 1/4 or 3/8 inch with some studs or something welded to the bottom to act as rebar and mounting. And weld up a sheet metal form to cast the concrete into. I would also use some rebar in the concrete. The sheet metal form ought to be light enough to get into the basement.

The upside is that the surface is tough and you don't have to remove the form.

The down side of this is getting it out of the basement. Reinforced concrete encased in sheet metal will not be easy to break into chunks.

Dan

Dan sez: "Actually HF sell all sorts of price point tools. For example they

Right on., Dan ! HF is good in a lot of ways and not-so-good in some ways, but overall the economy appeals to most of us. Did'ja ever notice those that lack experience always puff themselves up re. their "taste" for price and quality ?

Bob (caveat emptor) Swinney

It is also

Smaller granite surface plates are pretty cheap these days.

David Merrill

Why not fill with sand instead of concrete? Then you could just drain it from a hole in the bottom.

You'd really need a punt gun to apply that much bird shot in a reasonable amount of time, wouldn't you?

Mark Rand RTFM

All of the larger machine tools at work are on custom poured concrete foundations. Some, such as the low speed balancing machine (600rpm with a 50 ton rotor) have raised bases that were made in the way that you suggest... only more so!

I would suggest that if you think you will be moving it in the next decade or so, to paint a good coat of gloss paint on most of the floor where it is going to go. The concrete won't bond to the painted bit and should allow it to break away when you apply the sledge hammer to it.

Make a jig (or use the base of the mill) to hold threaded tubes for the mill's mounting bolts, they can then be cast directly into the obelisk without having to drill holes later.

The only think I can see wrong with the idea is that you loose out on potential cupboard space in the stand. You could always cast a couple of steel boxes into the stand to act as cupboards, and lessen the amount of concrete though!

Mark Rand RTFM

Newbie, no. Weird ideas? Well....

-Carl

Lots of guys here singing the praises to harbour freight tools, and about every other flavor of cheap import tooling. But they all know or learn that the stuff has it's limits.

The point was, I beleive, that going to the trouble of planting it on a concrete stand is rather excessive. It will not benefit from the attention, therefore it seems a effort for naught. I don't think that the OP really needs the permission of the group at large to build a concrete bench for it if that's what he wants, but when it gets out on a public forum, theres gonna be a pile of opinions, whether they are welcome or not.

The general tone of your replies is defensive and reads like someone that is wound up at least a little. Maybe I'm misreading it, maybe not.

Matters not, as free advice is guarunteed at least double your money back!

Cheers Trevor Jones

Yes they do. But the image conveyed by "Harbour Freight machine" is not the one that assosciated with the name brands like the Milwaukee, Makita, and that ilk. And we were discussing a milling machine, no? What do they stock in machine tools that fit the same strata as the name brand power tools?

As for the statement that they are what they are, I do not say that they were without value, rather that one must assess each on it's own merits. Many of the cheap POS machines are a great value, for the dollar spent.

Cheers Trevor Jones

Clean pea gravel. Even easier to clean up, as there is less dust to deal with.

Cheers Trevor Jones

That would work if you used a bit thicker metal than I was thinking of. The sand would dampen vibrations, but wouldn't do much for rigidity.

Dan

If you hand load shotgun shells..its a good place to store your shot.

Gunner

"Liberalism is a philosophy of consolation for Western civilization as it commits suicide"

- James Burnham

I just bought an import bench mill. the best I could find for $1600. It weighs almost 900lbs. and has a dovetail column. I welded a bench together for it but after mounting the vise I fing it to be too short. So tommorow I make another. My point is this, I was taught that next to safety. the most important thing about machine work is to have a rigid, solid set-up. If you want it in the basement, find a way. If you want to use concrete, ask around and be sure because it's obviously much more of a commitment that wood or metal. As far as the machine's quality goes, see point number one.

"When you buy the good stuff it only hurts once"

Good Luck Pal.

Best up-front gains on a minimill would be from improving the rigidity of the base to column attachment. Several good solutions online.

But it still needs a good solid base. I would lean toward a roll-around toolbox with a cast concrete top. Imbed bolts into it with the threads projecting about 1.5" above the concrete.

Now THAT'S a cool idea!

Gonna have to remember that one!

Cheers Trevor Jones

I'd do the opposite, embed grout-in anchors in the concrete. Studs sticking up out of something that heavy are asking to get bent.

Try this: .

Joe Gwinn

Damping and rigidity can be traded off, as their product is what counts: the higher the product, the better.

Some machine tools are made with a welded hollow metal (aluminum works) base filled with a special softish polymer concrete. One form is granite chips in epoxy.

Joe Gwinn

Ref: "Precision Machine Design", Alexander H Slocum (of MIT), SME 1992.

That's what I figured on doing with mine. But before I got to it, I acquired a Burke #4 horizontal, and I'm now considering combining the two machines. Burkenstein Mill.

One positive aspect I see right off is the reduction in vibration that comes with a greater mass. Since smaller machines tend to transmit vibrations to the workpiece more readily than larger ones, this alone would seem to be a benefit. I once visited a university lab that had an optical bench, a massive vibrationally isolated and dampened steel and concrete table to which optical components such as lasers and special microscopes were attached. The device was isolated on a series of hydraulic cylinders, but the assembly was located in the basement of a large building, mounted on what looked an awful lot like a giant concrete sarcophagus coming out of the floor. The principal investigator of the research project told me that the entire assembly had been located in the basement prior to the completion of the building, lowered in by crane. I can't even imagine what it weighed (probably on the order of 10 tons or so). ww88