Slab thickness for machinery?

[kpj]

I am planning on putting up a shop in the spring or next fall at some point and was wondering how thick to go on the slabs if I plan on having 1 or 2 milling machines, a lathe, and hopefully a CNC milling center. I searched through the forum and I couldn't find what I was looking for.

Thanks,

Ken

[Reflexx]

hey KPJ,

I just did it myself. I went 6"-7" thick. Originallly I was just going to do half 4" and half 6", but the cost was not that much more for all 6" thick. Still fricken expensive, and as you said: "but I never know where the machines might end up sitting in the future or if I add a lift"

REFLEXX :D

[DRM]

I did 5" fiber reinforced, no-rebar slab, and going on 3+ years of no cracking yet (fingers crossed).

I told the builder I wanted to be able to put in a lift later, and this is what he recommended.

[d.d.machine]

I have a 4" slab and its holding up ok ,,, the parts thats cracked is not under the machines ..... but next time I well go with 8" to keep down on Vibs from one machine to the next ,,,,, My big shaper can fook up the finish on all the rest of the machines in the shop .

Duffy

[MC]

I have a 4" slab and its holding up ok ,,, the parts thats cracked is not under the machines ..... but next time I well go with 8" to keep down on Vibs from one machine to the next ,,,,, My big shaper can fook up the finish on all the rest of the machines in the shop .

Duffy

HOLY TE MOLY 6"s minimum guys. Keep in mind kpj that a cnc is usually around 6-15 thousand pounds and will vibrate the crap out of the floor during heavy cuts. We have 12"s of concrete under our feet here but when we move to the new shop it will be only 8 which is fine for what we do (no stamping)

[Albin]

I did 5" fiber reinforced, no-rebar slab, and going on 3+ years of no cracking yet (fingers crossed).

I told the builder I wanted to be able to put in a lift later, and this is what he recommended.

I meant to ask what you used but then we got busy dissecting that Toy 4runner, I forgot.

Thanks,

Al

[PTSchram]

I was gonna suggest GO BIG, but got beaten too it. The more stable the machine is, the better cuts it's gonna make. At this stage of the game, concrete is cheap and easy to plan for. Expensive and damned-nigh impossible to go back and do it over if you didn't plan for it originally.

The importance of stability of the foundation is difficult to overstate. My floor is very thin (second floor) and my machinework shows it (except for the rare occasions when the planets are aligned just right). If you're gonna run automated machinery, it wants to be able to find the origin in the same place everytime-easier to do if the machine is stable.