This project is not complete as we had visioned it. But the submission must go in before midnight. It is, however, mostly finished except for the photo to mesh part. Therefore, this is the ongoing quest.
Step 1: Your STUFF
Vector Drawing Program
Mach3, EMC, or similar (http://www.machsupport.com/) (http://www.linuxcnc.org/)
CNC Router or a contract fabricator – (www.100Kgarages.com)
Staple Gun or screws
X-Acto, utility knife, something sharp
Blue insulation foam, 1"
3/4" Corian Plastic (counter top stuff)
Sandpaper, foam blocks, dremel tools
Step 2: My STUFF
Lots More Patience
Dust collection system
Step 3: Drawing Programs
There are so many design programs out there (http://www.freecad.com/) (http://crunkish.com/top-ten-cad-software/). Some are free, some are not. Try the free ones, or the trial downloads, and spend some time assessing their capabilities. Make sure you look at what they can import and export. This will be important in moving your drawing files to the CAM generator (more about that later). The higher end ones, have a steep learning curve and take a while to be comfortable with. The lower end and free are getting better all the time. Check out Sketchup (free) with the ruby script that allows output in .stl and .dxf formats. Sweet! (http://www.guitar-list.com/download-software/convert-sketchup-skp-files-dxf-or-stl)
Step 4: Output to CAM
Some drawing (CAD) programs have no way to get g-code from them. G-code is a language defining where the router must go to perform the task you have in mind and is generated by the CAM. Some CADs have CAM with them but they tend to be the pay for types. For those of you who are using a CAD program that does not have this function, you’re going to have to find a separate one to do this. Here is some links. (http://www.rhino3d.com/resources/display.asp?language=en&listing=545)
For those of you who want to learn about g-code there are sites that will show you what it all means. (http://www.cncezpro.com/gcodes.cfm)
Step 5: Head Hunting
Step 6: Selecting the Bit
Our router only goes one speed in rotation and maxes out at 25 linear inches per minute, so the only control we have is how deep it cuts per pass, and the inches per minute speed it travels thru the material. Before any machinery is turned on, install the bit into the router you have. Be VERY careful, they are quite sharp. I wouldn’t know that, but there are a wide range of band aids and compresses readily available in our shop, just in case.
Step 7: Load the Material
Make sure that the piece you load on the machine is bigger than the project. Seems obvious, doesn’t it? Also, that the material is oriented correctly in the X and Y plane. I never made that mistake before.
Many treacherous opportunities lie here. Cut the foam larger than the project. You want extra room for clamping down the outer edges with screws, cam locking devices, or even double-sided tape. In this case I used sticks and screws it clamp it down. Regardless of the method, one wouldn’t want the highly rotating router bit or the router itself crashing into something hard and unyielding. Some very interesting results WILL occur and you really don’t want that experience. The least is you may lose some steps in the g-code and get the remainder of the cut all cockety-wampuss, and the worst is flying bits of high speed steel flying around. Which brings us to the all-time favorite subject of OSHA, da-da… SAFETY.
Step 8: SAFETY
---Ears - CNC machines are loud. I like to put on noise cancelling earphones with my favorite music playing in the background. Not too loud as you want to lightly hear the machine as it runs, giving you a heads-up to any problems.
---Eyes and face – Flying objects do sometimes come from the machine, best to protect them. I use a face shield.
---Breathing – All materials have some dust created during the cut. Use at least a filter mask for non-toxic woods and cardboard. Use a much better mask for foam and plastics.
---(If at all possible make or buy a dust collection system to keep the fumes and dust to a minimum. That’s the next project for us after this contest. Wish I had done it earlier.) (http://solsylva.com/cnc/vacuum.shtml)
Step 9: Power the Machine and Computer
Step 10: Zero, Zero, Zero
Step 11: The Magic
When the cycle ends, and the router comes back to zero, turn it off. Then remove all the clamps, screws, staples, or what-have-you that is holding the material firmly. Pick up the piece and be amazed. Remove the waste sections, and vacuum or blow off the dust so the machine is ready for the next fabulous experiment.
Step 12: Examine
If you think it needs improving, return to Step 3, and go for Plan-B, or Plan-C. In my case, it always takes several iterations and tests to get the effect you want.
Step 13: Finishing
It seems that the stability of our homemade machine may not be as good as a commercial unit. That may be what left the grooves in the first Corian piece. The second try looks as if a line or two of g-code may have been jumped.The beginning of the second finish pass did start well as it began the forehead, but didn't appear to have touched the material throughout the remainder of the run.
After some sanding, she looked pretty good anyway, but I want the machine to do a finer job.I will need to also reduce the size of the polygons around her cranium, the're big and visable.
Well, time has gone wherever it goes and this must get submitted.
Future tests will, I'm sure, resolve the machine problems and I can get to the most perplexing part of this project. How do I make 3D meshes from photographs?
There are several sites I have found that will allow you to upload a series of pics and will return to you a 3D mesh to spatially define the subject in the three axis, X, Y, and Z. Although I have done a number of uploads using a small statue of Ben Franklin and my Wife (patient as she is), the results back were not good enough to work with, considering my lack of experience with 3D drawing. Working out this set of challenges will be at the heart of the next few weeks, and I will post the results here. When I can manage meshes of my kids and Wife, I will mount them on a nice piece of walnut.(http://www.123dapp.com/catch) (http://www.hypr3d.com/)(http://www.tgi3d.com/index.php?Page=PhotoScan)
Please post any help, ideas, or suggestions for this work. I doubt that this is the first time in history a head has been cut by a router.
Thanks for reading this far. The game is still afoot.
Step 14: Why We Want to Win
Our club of makers will continue to explore the vast world of CNC routing. We have in mind a large backlog of ideas that would be furthered by winning the PRS Standard 96-48-6 ShopBot . Our homemade CNC can cut 31” x 21” and cuts at a maximum of 25”/ min. The 4’ x 8’ table and 300”/min will vastly improve our ability to produce prototypes, develop and improve designs, create larger projects and test out 2.5D, then move to full 3D sculpting.
Here is a small selection of my personal list of projects:
Giant Spirographs using chalk for outside
Wing Ribs for Experimental Aircraft
Mazes for more than one player
Giant mazes on a half sphere to be played by young children
Interchangeable mazes of increasing difficulty
Picture frame mazes
Patterns for Cabinet doors
Wood Blocks for printing from ancient lithographs
Negatives for molds
Thank you for considering this submission