Going from pencil sketch to computerized laser cut

jmc · Nov 10, 2004

Say you have a detailed line sketch you want to feed to a computerized laser cutter that accepts dxf and dwg files. So after you scan the sketch, what keeps the laser from making multiple passes in sections where the line width was a little to wide on the sketch? (The original sketch is detailed enough you wouldn't want to go back an manually adjust the wide segments.)

rdln · Nov 10, 2004

There is probably a tolerance setting in the software otherwise anything that is in math will be recognized by the machine.

<font color="blue"> (The original sketch is detailed enough you wouldn't want to go back an manually adjust the wide segments.) </font>

Then the final part should be detailed enough no?

aardvark · Nov 10, 2004

The hand sketch will be scanned in as a raster file, similar to a bitmap format. The DXF and DWG formats are vector files. There is software you can use to conver raster files to vector files, but if the raster lines are too wide in areas, the conversion can potentially make the end points of the different vectors segments discontinuous during conversion. Most good software packages would compensate for this I assume, but I don't convert rasters to vectors often. Mostly I just export dxf's and pdf's from Pro/ENGINEER native drawing format.

How hard would it be to just draw the sketch into a cad station and export a dxf?

gsxr1100 · Nov 11, 2004

Another ProE user! Whoa. I now use UG and it is not as good as Pro!.

We have rasters at my work place that scans them in pretty **** good. At least my Kubota symbol came out nice...till IT deleted it!

You should be able to sketch the dwg better in ProE, UG, Cadam, Cadra, Catia, Autocad whatever and be cleaner.

RobS · Nov 11, 2004

Scan and import into your CAD program then redraw over it in a different layer. For the laser you'll need to make sure all the lines intersect properly /forums/images/graemlins/smile.gif

jmc · Nov 11, 2004

Everyone,

Thanks for the replies. A little better description:

This is an art project about 3 ft square completely covered in freehanded curves. The artist says that he cannot draw with a mouse/stylus like he can with a pencil so directly entering his work on the computer is not negotiable as far as he's concerned.

Anyway, following up on Jared 's lead on raster to vector file conversions, I found some companies who do this- $28.00 for a 12 x 18 inch scan. (scaleable to any size) And as Steve suggested, there are tolerance settings to avoid multiple parallel vectors covering the same (wide) line segment. The company tailors their settings according to what you want to do with the vector file.

If anyone is interested in how this turns out, let me know and I'll post a followup.

Thanks,

John

aardvark · Nov 11, 2004

The company I work for uses Pro/E here in the US. I actually run the US based mechanical engineering dept. My UK co-workers all use IDEAS, but are looking at going to UG instead. If they go to UG, I'll probably end up with that too, but I can't get rid of Pro/E because of legacy products. I've released 16 new products in the last two years all in Pro/E. We have released even more Pro/E based stuff prior to that.

John, it sounds like you found a decent place to do the scanning and conversion for you. Post a picture when it's all done. I have a couple vendors down here in Fort Lauderdale who have laser cutters and a water jet cutter. I'm actually farming out some BX23 components to them. You may want to ask your laser cut vendor if he wants a rev 12 or rev 13 or rev 14 dxf or dwg file. Both my vendors can take Autocad rev 12 formats, but they can't use rev 13 or 14. They both bought thier machines many years ago.

bontai_Joe · Nov 11, 2004

I'm interested in how it comes out. I use AutoCAD all day and if stored as a .dwg file, the lines can be stored as having no width, or any width value you want to give them.