[hooligan]

This is my first post and i can not be considered a "carver", but i had some questions. If you look at the attached pic what you will see is where I have created a carving file in my 3D program. I take a 2d flat line drawing and assign colors to it in a paint program and then assign varying heights to the colors so that when i model them i can keep track of the heights which let me sculpt muscles, haunches, heads, textures like fur and features that are more in the background than foreground. I can then take the resulting file and cut it out on my cnc machine.

First, does anyone else do this? Because my assignment of heights between say the left front leg and the right front leg differ to give it depth and in "real world" heights it is only a difference of 10/1000ths is there any good way to judge how to figure those heights? What you see is many hours of trial and error and i'd like to learn how to do this faster than what this took me. I don't think its that good but could be better. Anyone else use a cnc for carving? I read the "cheating" post (using power tools) and the "3D relief" post by Susan but what i think i need is advice on how to create the heights in my mind as opposed to how to carve them in the wood (or is there a difference?)

[squbrigg]

What is a cnc? A computer driven carving machine?

Power carving, as we talk about it here, is usually a rotary hand tool, such as a Foredom, Dremel or Micromotor. Machine carving would be a more accurate description for what you are talking about, for mass production.

Not my cup of tea, thanks.

Bob

[hooligan]

CNC stands for Computer Numerically Controlled. The idea being that if you look at the picture (top right) it looks like a topographical map (like a mountain range) the varying heights designed in the software translate to moves that the machine (a router) carves of the various features. Similar to a duplicarver in a sense.
I guess my questions were geared more to how to analyze a picture to decide where your highs and lows might be to create a accurate copy in 3d relief, what you basically do by hand.

[AlArchie]

Hooligan, (can I call you "Hoolie" for short?)

Using a CNC system to produce art of any kind is a "trial and error" method, no more or no less than doing it with a pocket knife or the best of rotary or reciprocating tools.

Until unless you can grasp the exact placement, in your mind, of the coordinates you need to accomplish the carving you are attempting, you will need to resort to the trial end error method. What you are attempting to do, in effect, is replace the knife in your hand with another "knife in hand", the CNC software and plotter. And just like training your hand to do the work, you will need to learn to teach yourself to "think" through the machine. It will do your bidding, but ya gotta train it!

There are several companies around that do CNC carving, and they employ some exceptional "artists" to do the initial work on CNC software. P. Graham Dunn of central Ohio is one such firm. They do custom carving and laser engraving on all sorts of wood products, from pens to small placques, to mantles, to alters and doors.

I know I'll probably catch some flack for this, but the artists who produce the original works at Dunn are the equall of anyone working "by hand".....they just use different tools. Conceptually they have adapted their thinking to coordinates in 3 dimentional "free space" just as we who do carving by hand have learned to translate what we visualize into completed objects with our hands.

Duplication is, I believe, wherein lies the rub with blade and power carvers. Once the original piece is completed and refined, the multitude of spatial coordinates are permanently recorded on the computer and innumerable identical pieces can be turned out by feeding the data into the CNC routing, lasering, or cutting machines.

Might I suggest you contact the P. Graham Dunn outfit and see if you can speak with some of their artists. They may be able to help you with the process. Or maybe not......it may all be very proprietary, but it wouldn't hurt to ask.

Sears is also marketing a CNC carving machine for around 2 grand, and maybe their instructional manual could help you a bit.

Been thinking a bit more about your question, and would just like to reinforce what you will need to do......and that is to THINK in the sense of using the X,Y,Z axis to define your work. I was trained in AutoCad, back when it first came out, but haven't used it since Release 11, so I may be more than a bit out of dat, but learning to visualize the "model space" they incorporated helped immensely in developing the 3-D models. I think you'll find the contrast between hand carving and computer modeling is going to be a mater of precision. When we "look" at an object and then attempt to translate that internal view to a carving, we utilize our visual senses to place the design on the wood both in depth and lineally. Pretty crude placement by comparrison, to the ten thousandths on mm's that the cnc units can accept.

And as far as that trial and error method goes, all my hand carving is done by trial and error. A little off here, turn it over and take a little more of there, then try that again and again and again, till I either get it right or add it to the woodpile! You'll just have to learn a different trial and error system.

Al

[hooligan]

Hello Archie,
Yes looking at the pic i posted i work in a type of cad/cam program that, by virtue of how you "sculpt" an object determines the code needed to translate that to the wood working in the X,Y,Z axis. I guess my questions need to be more in the realm of how to visualize anatomy. In the pic the mooses rump and shoulders are higher in the Z axis then his midsection. By sculpting it that way it shows the "definition" of the muscles apart from his midsection and other body parts. Given that that is a fairly straight side shot that might be easier than if he was standing at 3/4 profile.
Maybe I should be thinking more about studying the anatomy of a subject to get a better grasp of how to sculpt them?

[AlArchie]

Looking at the original picture and then your last cuts, it would appear that there are two concepts you may have some difficulty with.....not meaning you in particular but "you" in the general sense of the term.

Perspective and undercutting. A lot of the depth that is IMPLIED with relief carving is due to these two concepts.

Perspective is something that may be relatively easy for you to get a handle on. One thing to remember is that the perspective on a relief carving is very dependent on where the carving is viewed from. If you plan on displaying the carving at eye level, be sure you carve the piece from that viewpoint. If it will be lower or higher than eye level, the perspective you carve into it must be adjusted for best visual advantage, from those positions. This may require you to adjust the anatomical features to conform to the viewing position and the changes in depth that you want to convey. Fer instance, on that moose, looking at the piece from directly in front, the head is turned TOWARD the viewer, and may be best represented as slightly larger to show that it is actually forward of the body. And the surfaces of the nose, eye placement and antler orientation will change slightly due to actually cutting them back into the wood, as opposed to being drawn on a flat plane. Getting the hang of these changes in perspective will make the depth appear much more real than is actually carved.

Using the CNC system, you are going to have some difficulty achieving any undercutting unless you have a swiveling cutter head. Undercutting is simply removing material from behind an object in the foreground. One of the things this does to add depth and realism is due to the play of light and shadow into the carving. These undercuts can be used discreetly for subtle effects or boldly for some rather stunning visual "grabbers".

I'd suggest you go and look at some of Mark Youndt's work for some amazing use of these two concepts, and check with Susan's site for some tutorials on relief carving. (L. S. Irish) There are others here with works you can check on too.....Mark Gargac, is another.....aw, c'mon guys, pipe in here!

The concepts you will use for these relief carvings will be the same time tested ones that carvers of the old school use, and THEN, you can apply the "grunt work" to the computer and the CNC tools. OK, Mark, I don't mean the term "gunt work" in a derrogatory sense......just as the laborious part of the artistic process.

Al