Who uses a granite surface plate for their mills?

[xander18]

My mill (X2 CNC if you're curious) came with a 24"x24"x3" granite surface plate. So this thing weighs close to 200 lbs. I moved it by myself last weekend using a sling made out of ratchet straps and it was wildly inconvenient and probably pretty unsafe.

Since I'm a college student I move around a few times a year at least and I would really rather not deal with the surface plate since everything else in my little portable machine shop I can move on my own. So my question is, how necessary or helpful is it to have my mill on a granite surface plate? I'm not doing anything wildly precise, .001" is probably the tightest I could possibly hold on that mill and I don't anticipate ever needing that precision for my projects.

How many of you set your mills on granite and how 'bad' is it to not have it on granite?

[photomankc]

A granite surface plate is more often used for measurement rather than a base for the machine. It's used as a known flat surface for testing other surfaces against and for measuring features of a part as the distance from that surface. I have a small one that is more easily moved that I measure tool height with check parts with. Never seen one used as the base of a machine before.

[xander18]

A granite surface plate is more often used for measurement rather than a base for the machine. It's used as a known flat surface for testing other surfaces against and for measuring features of a part as the distance from that surface. I have a small one that is more easily moved that I measure tool height with check parts with. Never seen one used as the base of a machine before.

Using it as a base for the mill was what the previous owner was doing so I just stuck with it and the machinists I work with (precision CNC internship) thought that it would generally stabilize a mill. I don't really do enough inspection to need it for that, though.

[hoss2006]

Use it to make a CNC lathe.
Why I'm holding onto mine.
Granite surface plate lathe
Hoss

[eartaker]

xander18,

You want to have a surface plat that you can use, but one that size and for what you are currently doing is not needed. You could hold onto it for a future project or get rid of it, but as of now it has no good use with the X2 unless you have a place to put it on a stand to use it as a measuring surface.

[Fastest1]

You could give it to your wife for a chopping block! You will get a few points with her and if you are real lucky, you will get what nateman-doo was looking for in one of his latest threads!