[RCaffin]

Epoxy granite is all very well, but for 1% of the hassle I can go to a nearby stone mason and buy a tombstone blank already polished up and pretty flat.
Well, why not?

Yes, there are quite a few threads here about sitting a steel or aluminium frame on top of a granite surface plate, but that is not what I mean. I am asking about using a granite tombstone slab as the actual base for some heavy linear bearing rails. Maybe using more granite slabs as the uprights for a YZ gantry. (Or beyond that.)

If this has been discussed before, just point me in the right direction please.
If there are some commercial machines which already do this ... I know there are, but feel free to mention them.

Cheers
Roger

[awerby]

As long as the stone parts don't have to move, that shouldn't be a problem. The major issue will be making attachments to the granite, but you should be able to drill holes in it with diamond tooling (take your time and use plenty of water). Then you can set anchors in it to hold your fasteners. If anything comes of this, please post pictures of your build, okay?

[RCaffin]

Oh, cutting and drilling granite with diamond tooling is no problem. Well - it's a known technology, anyhow.
What I am hoping to find are pictures of someone else's build!

Cheers
Roger

[RCaffin]

Um - no one has done this?

Cheers
Roger

[CaptainVee]

I think the main problem is that they apear flat but are not.
For their purpose they only need to seem flat.

I used a piece of granite that was intended for the face of a building and it had a few tenth of a mm dip over half a meter.

[RCaffin]

So did you use it? If so, what did you do about the dip? Epoxy between the granite and the rail?

Cheers
Roger

[CaptainVee]

Ah sorry, forgot to include that.

I had acquired it to become my routers base but used it first to set the gantry straight by under-casting with epoxy.
Because of the dip it was hard to figure out when the cantry was set correctly.

[RCaffin]

OK.
I must find out how flat the local tombstones are ...
They might have some rejects or something. ("Look, awfully sorry, but he's not dead yet ...")

Cheers
Roger

[Eldon_Joh]

it is easier to scrap granite with a diamond sawblade than it is to scrape cast iron with a carbide scraper. you won't get 40 points per inch, but you will get .0005" per foot or better.

[RCaffin]

you will get .0005" per foot or better.

Yeah, well, that's not too bad.
I wonder what the polishing machines the stone masons use can do? After all, who wants a wobbly tombstone?

Cheers
Roger

[Eldon_Joh]

Yeah, well, that's not too bad.
I wonder what the polishing machines the stone masons use can do? After all, who wants a wobbly tombstone?

Cheers
Roger

i've heard the same ones used to make surface plates.. they just don't spend much time at it.

[louieatienza]

Um - no one has done this?

Cheers
Roger

Minitech uses black granite for their mini mills. Datron uses solid black granite for their CNC machining centers' bases. Also check out Aerotech; they use granite bases for their 3-axis CNC machine bases.

[RCaffin]

Minitech - ooh, cute!
Datron - yeah, seen their dental mills before. Rather impressive operations.
Aerotech - knew them from before for micro-positioning gear for optics. They have grown though.

But they are not hobby MYOG units by any means!

Thanks Louie
Cheers
Roger

[louieatienza]

Minitech - ooh, cute!
Datron - yeah, seen their dental mills before. Rather impressive operations.
Aerotech - knew them from before for micro-positioning gear for optics. They have grown though.

But they are not hobby MYOG units by any means!

Thanks Louie
Cheers
Roger

Well if you have a waterjet, huge gantry mill with flood coolant, and ridiculously expensive PCD endmills and drills, you can DIY your own parts from granite slab! I have a waterjet guy, next is to make friends with the countertop guys that have a stone cutting gantry CNC.

[RCaffin]

I had a long chat with a very old Italian stone mason not that far away. He usually makes tombstones and counter tops. He was quite keen to make up slabs of granite for me!
Hum ... :idea:

Cheers
Roger

[alexlee]

Hi,dear sir.I think i can help you.
Forgot to introduce myself,This is alex from china,sales from SUDIAO,cnc manufacture.
We have some special model for grantie,Marble Cutting,Drilling,Milling.Here is some pic.
If you are interested in,Kindly contact me directly,i will reply you ASAP.
My email is [email protected]
Whatsapp :+86 18668926716Attachment 266488Attachment 266488Attachment 266488Attachment 266490Attachment 266492

[RCaffin]

Hi Alex

Thank you, but machining granite is not what I was looking for. However, interesting photos.

Cheers
Roger

[alexlee]

Fine.Your business is tombstones and counter tops?
Our machine is professional for this,also we have video to that making.
Do you need that?
If you don't need,sorry to disturb you.

[RCaffin]

> Your business is tombstones and counter tops
Not at all.

I was talking about making a CNC machine using granite for part of the structure. Very different.

Cheers
Roger

[alexlee]

Ok.Thanks for your time,Hope your business going well.