New CNC Mill on the horizon

[Jonathan]

Ah so you've seen me mention sand before.!! Yes dry kiln sand works good and is easily removed.

That or seen someone else mention it - it's a well documented solution.

I'd go for epoxy granite over concrete. Concrete moves/warps after it's set and since you're using profile rails any movement in the piece they're mounted to could cause serious problems. If the rail is bent ever so slightly the slide coefficient of friction increases dramatically, so if this happens over a long period of time you probably wont notice until the machine stalls due to the greater power needed to move each slide. By that point some serious wear could have occurred to various parts in the system.

Frame looks appropriately sturdy, but I'd be inclined to add some smaller box section to link the legs. It wont cost much compared to the rest of the frame and could help with resonance, since at the moment you have a large mass supported by legs (rather like a cow which wobbles a lot if you push it!)

[JAZZCNC]

That or seen someone else mention it - it's a well documented solution.

I'd go for epoxy granite over concrete.

Ye but seemed logical has I mentioned concrete and he added sand which I've mentioned and recommended many times in the past.!! . . . . But does it matter.!!

Personally I wouldn't go with Epoxy or concrete.!! Sand is cheap the concrete example was to make a point that heavy or dense is good.!
Epoxy is not a good solution either has the heat from the large qty of epoxy could and will warp the steel.!! . . .Plus the cost of epoxy it would be just has cheap to buy plate steel.??

[fvfdrums]

Sands good with me likely hood is I'll need to move the machine at some point so the potential to "drain" some weight would be useful

[Jonathan]

Personally I wouldn't go with Epoxy or concrete.!! Sand is cheap the concrete example was to make a point that heavy or dense is good.!

Yes of course, sand is perfect going by the 'heavy is good' and reducing resonance arguments. However it doesn't add strength, unlike concrete/epoxy. I assumed you suggested concrete additionally for that reason. It's a shame the cost of epoxy is so prohibitive.

[JAZZCNC]

I assumed you suggested concrete additionally for that reason. It's a shame the cost of epoxy is so prohibitive.

There you go again with your ASS -Sume-ing.!!