3D Modeling of Existing Parts Tips and Tricks

[mattanonymous]

A couple of tricks I've learned are below. I'm just a hobbyist and am looking to find more tips. I appreciate any help!

• 2D scanner: scan (either a tracing or the actual part), import image into modeling software (I'm using SolidWorks), trace in sketch mode, give one of the lines a real dimension
• Modeling Clay: I've used it to get the rough look and pulled dimensions and angles from that, but it could also be used with the 2D scanner method mentioned above

Any neat things you guys do?

[curious aardvark]

I generally just use my digital caliper and measure the part and then design it in openscad.

[awerby]

I use 3D scanners for this; it's a lot easier than modeling by hand for complex objects. But if you're trying to replicate a mechanical type of part, you usually have to "reverse-engineer" the critical features, using the digital calipers or whatever to retrieve enough info to create an accurate CAD model.

If your parts aren't mechanical, and you can't afford a 3D scanner (although there are some relatively inexpensive ones now), you might look at photogrammetric solutions, which reconstruct parts from different 2D images. Autodesk has a free photogrammetry application called 123D Catch which you might find interesting.

Andrew Werby
www.computersculpture.com