part creation from scanned images?

I often create parts from cardboard cutout pieces provided by R&D. The
shapes rarely contain many straight edges, are usually fairly irregular in
nature, and not necessarily accurate.

Currently, I trace the parts onto some high accuracy graph paper,
manually plot points along the perimeter, and create a spline with a
reasonably close fit. I then create the part using a 1 to 1 print and the
actual material to be used, then check fit. Most times small changes are
made, some for funtionality and some for asthetics ( R&D doesn't care what
it looks like, if it works ), then another prototype part is made.

When the shape is verified, I then create an identical part using
tangent arcs/lines rather than splines. I do this because most machine
tools ( mills, lasers, ect ), have an easier time processing arcs/lines
rather than the many small line segments a spline produces when converted to
NC code for most, but not all, machines. My vendors really appreciate this
effort.

Rather than tracing/plotting I have had some limited sucess using a
scanned .bmp at the proper scale inserted as an object and laying sketch
points along the perimeter. Other formats don't work for me, some because I
don't have the appropriate software installed to view them, and some, like
jpegs, I can't seem to get an image to appear ( all I get is a small square
box ). Scanned .bmps become massive in file size and cause a significant
slowdown on my comp even though I have much more physical memory than is
required.

Is there a better method of obtaining the needed points from a scanned
image? If so, what format/software have you had the best luck with? Also,
is there a macrom or small utilitym out there than can convert splines to
tangent arcs/lines within a given accuracy? The manual conversion is a time
consuming PITA.

SW 2005 sp3
win xp pro sp2
p4 3.06
1 gig ram
ati fire gl t-2 128

 

Hi Brian,

You should check out this web site. http://www.baren-boym.com/ Under
SolidWorks tools they have a utility called "picture converter". It
may help you out. Basically it converts image edges to SW sketch
entities automatically.

Do you work for the Starting Line Products that produces aftermarket
performance Snowmobile parts?

 

I do.

 

Nice. I'm a huge snowmobile enthusiast. Rode Polaris for 14 years
until they just stopped keeping up on technology. On a REV now. SLP
makes some great products. I had no idea they used SolidWorks.

 

.....snip

Wintopo should help here. It will convert a raster scan into vectors
which you could import into a sketch. There's a free and a paid version.

http://wintopo.com/


Art W

 

What happened to flatbed digitizers?
Does SW support them?
Last I knew AutoCad did.

Why splines?

 

I've used the free and the paid for version of Wintopo, and they work,
but now I import an image into Deltacad and draw over it.

--
J Kimmel

www.metalinnovations.com

"Cuius testiculos habes, habeas cardia et cerebellum." - When you have
their full attention in your grip, their hearts and minds will follow.

 

Thanks for the compliment, seems i must be doing at leat part of my job
right <G>. The only ski-doo that I've ridden ( was a 2000ish model ) had
too high a center of mass in my opinion, and felt a bit unstable. But I'm
sure they've corrected that by now.

I've already spent quite a bit on new software so rather than ask for
the $600 for picture converter I'll use the freeware version of wintopo. At
least it gets me points that I can use which negates the need to manually
plot positions.