Indiana Limestone and 3D scan

[ManitobaKeith]

We are working on a project that I described somewhat in a different link. It involves 3D scanning of various historical wall carvings and replicating them by CNC using Aspire.
With assistance from Randall for the settings, we did this initial trial without major problems. There were a few glitches, but that is just part of my learning curve. All in all, the carving turned out quite accurate (depth) given that I did not have the correct bits (waiting over 2 weeks so far) and needed to prove the concept last Tuesday. The attached photo is during the cutting and it is exactly how the original showed. Total time for the carving was about 2:45. The 3D scan was overkill for the accuracy that I can attain as the STL file is some 98 Meg in size for a ~ 4.5 square carving. I was not involved in the scanning. This carving material is Indiana Limestone, but the original and hopefully the duplicate will be of British or French Chalk Stone. With the help of a few forum members in England, we will probably be able to determine the suitability of using the Chalk stone to replicate the originals. My main concern is whether the chalk will flake. That isn't a problem when creating an original, however when duplicating it would not be accurate or acceptable if it flaked.

More information and photos as time progresses. Thanks to all that have provided and still are providing assistance with this project.

[stankern]

whats about machining soap stone with the cnc is that possible ?
I've done woods of all sorts , aluminum and brass (thin)
Soap stone would be interesting if you can hold it down

[Rcnewcomb]

Soap stone machines very nicely.

[rickw]

Rcnewcomb
Could you enlighten me on bits to use on soapstone ? Feeds and speeds ? Sounds interesting,like to try it. Course , i dont know where i'd get soapstone in mid north indiana. I can get limestone easily but i worry it would be real tough on my equipment. Thanks, rick

[Rcnewcomb]

Could you enlighten me on bits to use on soapstone ? Feeds and speeds ?

I use solid carbide bits. After a bit becomes dull from wood cutting we move it into the "stone bit" pile. Stone doesn't require as crisp an edge on the bit. I've used V bits: 60º, 90º, and 120º, ballnose: 1/4" and 1/8", and some end mills.

For feed rates lately I've been using 0.5ips to 1ips at 13K RPM. Limit your pass depth to no more than 0.125"

I would recommend starting with a simple shallow V-carving. Here is one of the first pieces I tried in Kasota limestone: ->Link
Practicing with Indiana limestone is a good place to start since soapstone is 4 to 8 times more expensive -- at least where I live.

You can get soapstone from a stone wholesaler in your area. Buy some stone from them (best $40 I ever spent) -- that gets your information in their computer. Then bring back samples and have them show them around. That is how we got our first job, and since we were already in their computer it was a simple thing to have them change us from a customer to a vendor. Since then they have always given us samples to work with.

[John Murphy]

One more question Randall if you don't mind.

When you cut soap stone, are you cutting 3d images, or sticking to lettering and profiles?

Thanks
John

[Rcnewcomb]

Just regular v-carving. Sorry I just have the one example to show - and a poor photo at that.
->Link

[madtownrob]

I have cut some soapstone along the same speeds that Randall has. Here is a small example of a 3d project cut in aspire, maybe cut 1/4" total in depth. My first real modeling project with aspire

[rickw]

Thanks a bunch Randall. Cant think of much in the carved stone line i could do and sell right now. But i haven't thought along those lines. I do like soapstone though. Hmmm.

[Rcnewcomb]

Can't think of much in the carved stone line i could do and sell right now.

Your best bet is to carve some samples and show them to the stone wholesaler. People who design and install fireplaces are another potential market.

[gravirozo]

hello all

these stoneworks also need to be some class in october...

thanks
viktor

i choosed this post because all of "testers" has post here...