Binkley Uses CNC Machine to Carve a ZBrush File




michael binkley sculptor on stone sculpture 3D zbrush virtual design cnc machine

The next step for me on my virtual sculpting path is to have a CNC robot carve one of my 3D ZBrush compositions. My friend and colleague, Carl Nelson invited me to send him one of my virtual sculptures to try on his 3 axis CNC machine. CNC stands for Computer Numeric Controlled machine.

Carl brought a Pro4824 CNC router to the NWSSA Oregon International Stone Carving Symposium at Suttle Lake, USA (above) in August that had been adapted for carving stone. I emailed him my virtual ZBrush file in advance, and Carl was able to partly carve my abstract female torso in Texas limestone. Since there was enough space available in the chosen limestone block, Carl added a second torso to the file and carved two identical sculptures, inverted beside each other.

Since this CNC machine has 3 axis, it was only able to router down to the widest points of the sculptures, but unable to undercut from the top. After getting to the halfway point, Carl then flipped the stone over so the machine could successfully carve the other side of the sculptures.

michael binkley sculptor on stone sculpture 3D zbrush virtual design cnc machine

The ZBrush file (above left) is a mesh and is not sufficient computer language to operate the CNC machine, so Carl had to use a translator program to enable the machine to carve the shape I designed. Above right is an illustration showing my abstract female torso laying on her back in black, translated into a language the CNC machine can understand. The machine needs a 0-0-0 reference point in order to carve the sculpture correctly. Therefore, Carl imbedded the bottom of the design in a block that would not be carved by the machine. Since the top of the sculpture is quite delicate, Carl left a block of stone at the top as well. The yellow lines show the path of the rotary carving head of the CNC machine.

michael binkley sculptor on stone sculpture 3D zbrush virtual design cnc machine

The raw limestone block was secured into the carving bed of the CNC machine, and after a few hours, the machine worked away, removing the superfluous limestone and leaving the image of the two torsos. The sculptures are revealed looking like a topographical map, as each successive pass of the carving head was approximately 1/32″ down from its predecessor.

Once complete, I took the sculptures back to my studio to separate them into two pieces. I will complete one of the sculptures, but leave the other as is for future demonstrations. Here is a short vid of this part of the process:

What do you think of me using a mechanical assistant to help me to carve? Would you feel differently if I employed a human as an assistant? Let me know in the comments section below.

4 Responses to “Binkley Uses CNC Machine to Carve a ZBrush File”

  1. I think it is great, the more tools the more creativity. Do you think it will be faster? the nice thing is you do not have to do bronze’s to get more of the same. Is it expensive? Is the model hard to do? Can you make it any size or what is the limit of the size? Look forward to your next post

    Reply
    • Michael Binkley

      Thanks for writing, Donna.The carving process will be faster, as the machine is more exacting than I am at roughing out. Expensive is relative term. I do think there is a point of diminishing return, so perhaps smaller scale sculptures are best carved by our own hand – at least for now. This experiment was with a 3 axis machine. I’m going to look into a 6 axis machine that’s available for projects in Nelson, BC. This service has a minimum of $2,500, so a carve project has to support that in the budget. The ZBrush program is challenging with a steep learning curve – at least for me. The limit of scale is how large a CNC machine can work. I’ve read of machines that can carve up to 10 by 4 square feet. Cheers!

      Reply
  2. I love the potential of this but the unknown factor of cost makes it difficult to go with. Can it do granite? What is the name of the contact company in Nelson? I am in Peterborough, Ontario and I like to use Canadian companies.

    Reply
    • Michael Binkley

      Andrew – Thanks for your comments. There are tools for carving granite; it’s best to check with a prospective service before committing, but granite can be carved. Pat Doratti runs the CNC machine in Nelson, BC. He does not appear to have a website, but his LinkedIn page is https://www.linkedin.com/in/pat-doratti-86831b6/. Cheers!

      Reply

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