Carving Limestone slab

Hi Everyone,I was in a store that has a sculptor using Limestone,the question I have can it be carved on a Shapeoko and if so are there any issues using the material.I am in an region that has a quarry cutting slabs for cladding and walls

I v-carve marble with my SO3 XXL, and from my cursory look, they are about the same hardness, so I would say yes. I use inexpensive 6mm shank PCD (PolyCrystalline Diamond) bits from aliexpress, because the ones from places like ToolsToday are nearly $200.00/ea.

EDIT: Here’s the link to my post about carving marble tiles.

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This is on my long list of things I wanted to do. How is the tool life?

I neglected my cyclone dust collector hopper and filled it up and then packed in my MERV 15 filter with wood dust, so I have not been cutting for a while,but. . . I have v-carved 15-20 4"x 4" marble tiles, and so far I have not seen any degradation of the bits I have been using.

I have tried the 45deg, 60deg 70deg and 90deg bits, and none of them have spontaneously exploded or otherwise failed unexpectedly. I have used the 70deg the most, and the one that I have used for ~10 tiles appears to cut just as well as it did when it was new.

I have also purchased a few of the PCD straight cut bits as well in 3mm, 4mm and 5mm. I have only used the 3mm on one tile just to try it out. It worked, but it leaves a shiny surface and the v-bits leave a matte surface, so there may need to be some post processing to make it less obvious there were two bit used.

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there is a video about it on youtube

The most important thing I remember from it is that you really really do not want to inhale the dust it generates, so … take a load of precautions.

hmm soapstone not limestone…

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It’s one of the materials listed at:

For more information see:

https://wiki.shapeoko.com/index.php/Materials#Limestone

Well I thought there could have been some real issues but If I take it slowly and good dust collection I am going to try it.The guy doing the sculpture here is using a very white limestone and relatively dense and certainly not crumbling when carved.

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Here’s a few marble coasters I made last night for a friend. Used a 70deg PCD V-bit and a max depth of 0.060". Took 30 minutes each because I ran at 20ipm.

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These are really elegant, nicely executed.

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Thank you. I try to find a nice font to use, and after going through all of the ones I think look nice, it seems that Times New Roman almost always wins out when I show the mock-ups to the customer. The biggest issue I have is centering the engraving when I have the design close to the edges.

These “4 inch tiles” are actually 3.875" nominal to account for a 0.125" grout line. However, they vary up to + / - 0.1"-ish. Plus, the tumbled edge radius is ~0.04"-0.06", so I can’t get too close to the edges.

I typically do not get closer than 0.100" from the edge of the “ideal” dimension of 3.875". then I measure each tile and adjust the offset to keep the design centered on the tile. I’m at work now, but I will upload a pic of the indexing tool I use to hold them later tonight. It makes life easier when engraving multiple tiles in a single session.

Also, each tile is a different thickness, and some are “drastically” different thicknesses - up to 0.125" different thicknesses, so a Z zero is required for each new tile at a minimum.

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They are brilliant,I have some one inch thick slabs of limestone to be cut for me in the next few weeks so will be interesting to see how I go with it.

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