using cnc machine to sculpt clay ?

[tree]

My brother is very good at model clay sculpting. It takes him along time to create his pieces. Would a cnc machine be able to duplicate /sculpt his art work from model clay? I am a newb at cnc i only heard of the machine 2 days ago.

[paulC]

All a cnc machine is, is a computer controled rotary tool.
Normal clay would wrap around the tool and just make a mess.
If the clay was dried as you would before fireing, I would think it possible.
You would need to generate the code to control the machine. This is done using CAD/CAM software. This is not something cheap or easy to learn. It is possible to copy an object but again this needs software and a probe fitted to a machine.
There is a lot you can learn simply by looking around this site, so have a good look around. There are people here cutting all sorts of material.
Paul

[ger21]

These gus are cutting clay. http://tarus.com/styling.htm

[cbass]

Originally Posted by ger21 These gus are cutting clay. http://tarus.com/styling.htm

Cool link Ger, I had never heard of these guys before.

As Paul suggests, it will really boil down to the consistency of the clay, and what typ of cutter is used. I plan on trying this myself, but am really more interested in machining fired ceramics.

Carlo

[cadman]

In the automotive industry, concept/prototype vehicles are machined from wooden frames that are covered with clay. A couple of my former customers did this at their shops. The clay is allowed to dry before machining and not fired. GM has a running commercial that shows a few seconds of a clay vehicle being machined on a 5 axis router.

CM

[chris1234322]

Has any one ever come across any information in this forum or else where about making a Tarus style CNC machine for cutting foam, clay, or wax? I have been casually searching for months. Is there a specific name for the type of X,Y,Z set-up? I would like to build a mill with eight feet of x travel, 6 feet in the height, and around 4 feet in width. Any information would be greatly appreciated.

Chavant makes the modeling clay that many car companies use for milling and sculpting. It requires warming to apply to an armature and when it cools it hand models wonderfully but requires a few passes when CNC cutting.

[Splint]

For what it's worth the styling clay used in the prototyping industry is synthetic clay and never dries out or cracks. If heat is applied it becomes soft and plyable and then melts. If excessive heat, like a flame is applied, it will scorch and become useless. Feeds and speeds for milling synthetic clay have to be low to avoid creating excessive heat which makes a mess of he job.

Cheers
Splint

[replicapro]

who knows if it will work, but.....
Why not put a clay knife on the head and simply let the mill drig the knife instead of using a endmill. You would not even have to turn the spindle on, just let the machine scrape the layers of clay off.

At least you should be able to get some basic shape, then switch to a smaller knife tip and do a finishing pass while moistening the clay. You could even put a clay sponge on the tip and do a smoothing pass.
If you are on 4 or 5 axis it should come out nice after a bit of practice.
If you mess up, just start again, no material would be waisted like a metal part would.
Nice idea by the way.

There is a clay called super sculpey you could use that can be baked in a home oven after to harden it.

[cbass]

Originally Posted by replicapro who knows if it will work, but..... Why not put a clay knife on the head and simply let the mill drig the knife instead of using a endmill. You would not even have to turn the spindle on, just let the machine scrape the layers of clay off. At least you should be able to get some basic shape, then switch to a smaller knife tip and do a finishing pass while moistening the clay. You could even put a clay sponge on the tip and do a smoothing pass. If you are on 4 or 5 axis it should come out nice after a bit of practice. If you mess up, just start again, no material would be waisted like a metal part would. Nice idea by the way. There is a clay called super sculpey you could use that can be baked in a home oven after to harden it.

replicapro, I've thought about this before.

If you're talking about loop tools, I think it would take more effort than its worth.

http://www.clay-king.com/kemperlist.htm

You would have to keep the tool perpendicular to the path, and if you start dealing with curves, you'd have to continually rotate the tool in relation to the path. Also, you need to remove the material, so it dosen't get in the way of the tool when it comes back to do another pass. Those loop tools would slice the clay, but wouldn't remove it from the work area.

I imagine using a rotating bit with an upward spiral. Augment this with an compressed air nozel on one side of the tool pointing to the clay and into a vacuum nozel (shop vac) on the other. This would kick up the heavy chips on a regular basis. I think that would work.

Carlo

[ger21]

Originally Posted by chris1234322 Is there a specific name for the type of X,Y,Z set-up?

You want a 5-axis machine.

[pointcloud]

Do not try to use clay like a potter would it is a TOTAL WASTE OF TIME TO APPLY IT TO A SURFACE. 99% of clays shrink, even the slightest amount would cause it to crack and then mearly fall onto your machine or floor.

I contacted Tarus, first they said that they would sell to me there machine clay, then it was like no one would help. The clays to use must have oil to prevent drying. Clay will come right out of the bit, it will not gum up the tool UNLESS you are cutting to slow, to deep, or you have a streight cutter. It will work just like a tractor tire, self cleaning.

I would love to see a video of someone machining fired clay of any kind. Not saying it can't be done, Just want to see.

[chris1234322]

Chavant make many different kinds of clay and you would want their industrial clay for milling applications. The clay is put on hot and after it cools it's cuts OK.

For me the only reason to use clay for milling is that it the quickest way to develop sculpture because it can be rework by hand after machining. You could build a model with a 3d program mill it out in clay and see that your volumes and proportions are not what you thought they would be. Then you can quickly remodel by hand. To me this is the single advantage of clay over other materials like foam and wax. On my little mill I can cut wax and foam parts much faster and with better surface quality but clay is easier to model by hand.

Milling pottery clay in any state would be a no go for me. I have be using pottery clay for 20 years for pottery,sculpture, and mold making and chavant industrial clay for 7 years in the auto industry and for personal projects. Pottery clay is abrasive in any state. I would think of it as something like 300 grit sandpaper dust. It would not seem to do much in a positive way for the rails and ball screws of a cnc machine. Industrial clay is made of wax and oil and may be a little pottery type of clay in it's mix some where. Industrial clay take years to dry out and get crumbly or dusty.