Tracing Complex 2d Contour

[kgwhipp]

Hello All,

I've been at this all day trying to find a way to digitize a 2d part so we can create a good clean DXF for sending to the be cut on our waterjet.

Previous workflow usually involved scanning, PDF, open pdf in Solidworks and draw lines and tangents, splines over it until it was done.

Unfortunately a customer has provided us with a 2d part that has very few, if any, straight lines and is intended to fit into a console section of a vehicle. (Imagine a carbon fiber "inlay") and we're having a tough time getting anything to be "perfect" when we finally cut the part out and do a test fit. The customer supplied (hand cut) sample fits perfectly and is very flat. Our 2d dxf has to be VERY accurate to get the proper fit.

What would be the "modus operandi" on something like this? I've considered 3d laser scanning, and we actually just acquired a Wacom Intuos 5 tablet to try laying the part atop and tracing (I didn't think was going to work well considering the scaling, jagged lines, and pen tip thickness).

When I use splines in Solidworks, the curves all end up being "off" because the inflection points aren't located precisely, thus the part ends up cutting with a bad profile/fit.





-Kevin

 

[flash3780]

To me, they probably should give you a blueprint or a solid model if they want it perfect. That said, I'd think you could CMM trace around the profile with a Faro arm or something.
Given the picture you posted, you may be able to trace the shape in Inkscape? It's easy enough to make adjustments there if you're off a bit.
Maybe something [link

http://files.engineering.com/getfil...9a94aa4a30d5&file=carbon_fiber_template_2.svg

]like this[/url] (SVG) or this (PDF)?

 

[MikeHalloran]

Can the waterjet trace a part?

It seems an odd question, but bear with me.

I used to work at a tin shop that had an _ancient_ plasma cutter. I was surprised to learn that it had a tracing accessory, e.g. some kind of lamp/photocell reflective scanner that replaced the torch, and used a special mode of the _ancient_ CNC controller, to trace the outline of an arbitrary part, and generate and store a G-code file that could thereafter be used to cut a duplicate of the part.

Except for finding a large piece of clean cardboard to act as a background and placing the part on it, the operation could run unattended, and didn't require the incredible amount of manual labor required to produce a shape file with a CMM; just press the start button and let the head follow the part's edges until it was done.

I'm just wondering if newer equipment might also have some of that ancient machine's capability.





Mike Halloran
Pembroke Pines, FL, USA