digitizing 2d templates?

[shadybacon]

Hi everyone,
I am currently bidding a job that will involve a lot of templating for curved moldings and am exploring the possibility of purchasing a laser scanner to to scan the templates for cutting on the cnc. I do not require 3d. Can anyone offer suggestions as to how to accomplish this? What I hope to do is place the templates on the cnc, scan them and export to a dxf or similar file that I can generate g-code from.
Thanks for your help.
Jon

[ger21]

What I do when I have to match curved work (woodwork, which I think is what you mean), is to measure the chord at any location on the arc, and then measure the distance from the center of the chord to the arc. Then, in your CAD program, draw the chord, and the line perpindicular to it, and using these endpoints you can draw the arc with the same radius. The bigger the chord the more accurate you'll be.

[MILLMANM]

how bout hand tracing the profile on paper ,then scan it in to a raster vector progam
and prduce a dxf file for your cam system.
just a thought
Brad

[Dan Fritz]

We have macros for Fanuc controls that will let you digitize any 2-D or 3-D surface with a touch probe.

If you have a Fanuc control, and if you plan to do this often, it might be worth the trouble to connect a simple touch-probe. If this is just a one-time job, then the cost of the probe will probably be too much.

[High Seas]

Are you trying to go from scan straight to cutting product? If so, a route would be something that give you stl output (or use a home built scanner and convert with Acutrans) then use Stlwork to generate g code. If not, you could make a probe, use Mach2, create a point cloud, use polyform to make it CAD useable, then from CAD back to Mach2 and cut. Sorry I'm not near my shop/garage and machinery to ops check this approach - but I've had a bit of time to think about it. <Note:I'm not associated with MACH2 or IMserv - but both have good products!>
Jim

[imserv]

Slice a moulding cross section 1/8 thick or less, paint it black( if it is uniformly dark or light wood you may not need to paint the cross section), and then scan it with a flat bed scanner with a white cover(contrasting to the wood color). The contrast will provide enough resolution to create a usable image for even the worst raster to vector conversion progrm.

You can also insert the scanned image into most cad programs and use heads up digitizing to create a vector tracing. The trick is to use the part on the flat bed scanner and not a traced line. With heads up digitizing, you sketch points along the edges of the cross section and create lines, arcs, and spline/nurbs curves.

Fred Smith - IMService
http://www.cadcamcadcam.com/hobby