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lto
06-27-2006, 09:20 AM
I haven't noticed anyone on this forum using larger digitizing tablets/boards such as those shown on this site. http://www.logicgroup.com/Software/CadDxfDigi2.htm

Other than the initial cost of these, are there other drawbacks to using them to rapidly reverse engineer 2D parts to be cut? For example: imagine a need to replicate victorian gingerbread for a restoration project.

Any thoughts?

patricktoomey
06-27-2006, 01:20 PM
I have a Calcomp Drawing Board 2 (12"x12"), A Calcomp Intuos 3 (9"x12") and a GTCO 36"x48" rollup. I have used the GTCO for cad takeoffs for house and furniture plans but I don't know that it would work for tracing actual parts. You have to get the digitizer pen or puck right at the edge of the part which would not always be practical. The GTCO requires pretty close proximity to the pad surface so trying to trace an existing piece of molding that's 3/4" thick wouldn't work. The Calcomp works out to maybe that distance but it would be squirly and the point would drift around killing the accuracy. If you're talking about digitizing large plans for moldings or parts then it would definitely work.

For recreating gingerbread I have found it to be accurate enough to take high-res digital photos with a ruler laid next to the part. A sticky backed measuring tape like they sell to stick on extension tables for miter saws works great for moldings that are already installed. If you're careful to take the picture as close to straight-on as possible the distortion is minimal. Once you have the pic, you can trace over it in Illustrator, Corel Draw, ArtCam, etc. to get your vectors. I know this is not a high accuracy method but it's fast and for moldings and such should usually be sufficient.

One additional trick. If I will have a hard time getting a straight shot of the parts, like molding that's already installed, I take two aluminum squares (1/16" thick with double stick tape on the back) and position them upper left and lower right of the parts so they're in the picture along with the ruler. Then in Photoshop, I can shear and deform the picture until the squares are square and then take my scale off the ruler.