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cycollins
02-05-2007, 05:58 PM
I'd love for any successful user or CW staff member to chime in on the feasibility of the following project:

Imagine a simple human figure standing upright with arms at the sides (but not pressed agains the side - i.e. separated by some distance from the side and hips). Let's say a scale of 1" to 1', so call it 6" in height. I'll throw in an image if I can manage it, in case I'm not being clear with the descriptions. Anyway, as we all know from our days as geeky young lads (apologies to the ladies out there), such a figure can be successfully cast in plastic with a two-piece plastic injection mold, because that's how all our army men, Gumbies and Major Matt Masons, etc. were produced. That's because such a figure has no major concavities or undercut to it, if it is viewed separately from in front and in back (with the possible exception of ears and nostrils, which can be faked and forgiven - also assume the hands are in a fist or a knife-hand kind of pose - no fiddling with fingers.) Perfect for two-part molding. Of course you can do even better if you can dismantle the figure (witness Barbie and GI Joe), but lets assume a one-piece figure for now.

So, imagine a possible CarveWrite recipe for executing such a figure in wood. Assume we have a hight-field representing the front of the figure and another representing the back. Now, we take 2" X 2" X 10" work piece and we carve the front of the figure into one side. We also carve out all the negative space to the left and right of the figure down to the maximum 1" cut depth (also between the legs and between the arms and sides), leaving only a 1/4" margin of the left and right of the work piece. We'll do the same with the top of the figure, leaving an inch or so of margin, but the feet of the figure will remain contiguous with the work piece. Thus if you were to stare down the length of the work-piece, you would still see a 2" X 2" square, but if you looked at it from in front, you would see something like your figure, lying on its back in a tight-fitting box, half filled with liquid (hopefully an image will be provided to illustrate that lyrical description). OK, so now we turn the work piece over and lay down the height field for the back of the figure (hopefully getting the registration just right), using the same rule for the negative space of the figure. Presumably now you would have something that looked like your figure, with the feet attached to a 2" X 2" X 2" block, 2 "walls" on either side of 1/4"-thick wood and a 2" X 2" X 1" "roof" about an inch over its head. Now remove the piece, take it to a conventional circular saw cut the feet free from the base, and you should have a free-standing statuette.

Using this recipe, the work piece is always a single piece of wood, while it's in the CW machine (I read the warning about accidentally severing a piece of wood in the middle of a project). At no point do we have a cut-depth that violates the 1" rule (although I suspect it would be better to use a thickness of less than 2" to make sure that proper piercing would take place). And at no point does the CW machine have to do anything other than produce relief.

Does anybody whose had practical experience with the machine actually think this would? How 'bout those who designed and produced the machine? Too ambitious? What if we scaled back the goal of the project to only be a dowel-like subject, like a decorative pipe or recorder, rather than something as intricate as a manequin? How about the basic idea of a front/back carving with some piercing? Anybody want to throw in a guess?

BobHill
02-05-2007, 06:25 PM
Put your wood in a sled, then once you have the figure cut on the one side, turn it over, being absolutely sure it's repositioned in mirror to the cut side, attach it to the sled (perhaps some sculpting clay for balance and cut the second side. Experimentation before success, I'm sure. And basswood would be a good one until sure of the process.

I believe you'd have more trouble designing the figrures in Designer than the machine having trouble carving it, though.

Bob

cycollins
02-05-2007, 09:21 PM
...which is why I would write custom mesh-to-CW-pattern converters. I have (or will have) meshes of the figures I wish to carve out. All I need to do is render them to a height field of the right density and save them as an image file that the CW software can digest.

Let me see if I understand your suggestion for a sled + sculpy solution. Are you suggesting I not bother trying to keep the work in a contiguous block of wood? Rather I should fill the empty volume on the side that I carve first with some kind of clay to suspend the figure which will ultimately be dislodged by the reverse-side cutting?

The reason I'm not quite seeing the vision of the sled in all this is that I thought the CarveWrite already had pretty good mechanisms for squaring and securing the workpiece. Is the idea to keep the clay from contacting the runner that moves the wood (I'm sure there's a better name for it than that, but you know what I mean)?

cycollins
02-05-2007, 09:27 PM
The clay and the sled, I mean. The interesting side-effect would be that the clay actually DOES form a mold. In other words, if I were to use some kind of casting plaster in stead of clay, I would get two-for-one. The plaster would form a mold within the framework of the wood. After the reverse-side cutting was done, I could put some mold-separator and another layer of plaster on the finished product. Then I'd have a two-piece mold AND the wooden figure. I'm not sure why that's cool, but I like the possibility of having a wooden figure and the same figure produced in different materials as well.

BobHill
02-05-2007, 09:48 PM
Don't forget that if you have plastic or molded figurines, that if you put them into a clay bottom (on a sled, of course), then let the 3D probe do it's job, No design problem and if you're any good at modifying the plastic figures, that's a big advantage. Not only could reproduce the original in wood, but could easily change the size (scale).

Bob

cycollins
02-06-2007, 12:32 PM
Actually, for my application, I won't have physical originals, which actually makes it even easier to resize. However, I'm told that once you get beyond a certain resolution, the faceting of the tesselated mesh is visible, so I might have to introduce some kind of surface fitting. Kind of fun anyway.

cycollins
02-06-2007, 12:36 PM
Actually, for my application, I won't have physical originals, which actually makes it even easier to resize. However, I'm told that once you get beyond a certain resolution, the faceting of the tesselated mesh is visible, so I might have to introduce some kind of surface fitting. Kind of fun anyway.