Tracing Tools for laser foam

[Sheldon DeCosse]

Hello all,

I have a Universal Laser VLS 6-60 60w, and have been struggling with a good and reliable method to trace random tools, wrenches, screwdrivers, etc... to cut out Laser foam for special tool cases.
I have tried taking pictures and importing to corel... the trace function picks up shadows, etc. Is there a quick way to do this for a nice tight fit on tools with out re drawing and scaling them all?

thanks in advance.

Sheldon

[Matt McCoy]

Sheldon: You could photograph the tools on a white backdrop (e.g., poster board or sheet) outside or with even lighting and import it into your graphic software of choice. Try to shoot perpendicular to the face of the object and be conscience of lens distortion. Adjust brightness/contrast to simulate a silhouette to give yourself a good starting point. Tweak what the auto trace has trouble resolving. Adjust scale to match your measurements with calipers or a ruler.

[Joe Hillmann]

Put the tools on a scanner and scan them in. Convert to a bitmap. Convert to 1bit black and white with the slider set as dark as you can while keeping the background white. Then trace the bitmap.

Although that will only work for tools that sit right on the glass or have a very small gap between the glass and tool.

[Ross Moshinsky]

Scanner is better than photograph. Tracing with a pencil and then scanning is often the better method when applicable.

There are boards out there where you can put the object down and with a stylus mark the points or trace the object and it directly imports into a drafting program. They aren't cheap but aren't crazy expensive either.

No matter what, this is not the fastest process in the world. You should plan and charge accordingly.

[David Somers]

Sheldon,

I agree with Ross and Joe. Scan it. A photo will work but a scan is easier. Also, be sure to measure the object and scale it in your graphics program to match. not all scanners will produce a 1 to 1 scan. Better safe than sorry until you know the ins and outs of your scanner.

Dave

[Dennis Rech]

Hello all,

I have a Universal Laser VLS 6-60 60w, and have been struggling with a good and reliable method to trace random tools, wrenches, screwdrivers, etc... to cut out Laser foam for special tool cases.
I have tried taking pictures and importing to corel... the trace function picks up shadows, etc. Is there a quick way to do this for a nice tight fit on tools with out re drawing and scaling them all?
Sheldon

I make gaskets for antique engines and machinery and I find the easiest, fastest and most accurate method is to take a zoomed in digital photo from about 5 feet back to eliminate parallax and then to manually trace the object with a CAD program. I use the drawing portion of V-carve because of it's excellent node editing features. With a bit of experience, it only takes a minute or two to trace the required features and to scale the dxf file by measuring the distance between too points, usually bolt holes.

I have found that scanners do not work too well on three dimensional objects, too many shadows and reflections and software tracing follows the shadows and reflection instead of the object. Scanning existing gaskets hasn't worked for me. The old gasket is usually warped and misshapen and even new gaskets or original objects end up with all sorts of jaggies when bit map traced.
Dennis



Engine cropped.jpg
Gasket cropped.jpg

[Glen Monaghan]

I'm with Dennis on this. My experience with scanning of 3D objects is that there are usually shadows, plus most consumer grade scanners have a bit of parallax in them (of no consequence for 2D scans but problematic for 3D if you are looking for close tolerances). Use a high megapixel camera, on a tripod, with as much zoom as you can to take a picture from as far back as you can with the object perpendicular to the lens and framed to fill as much of the image as possible. You can eliminate most of the shadows by positioning the object above or in front of a white surface with lighting from both sides, diagonally positioned so any shadows hit the white surface out of frame. Since you are only really interested in the outline, you can manually set the exposure to somewhat blow out the background while drastically underexposing the object. Ideally, you'd get a pretty good silhouette, just make sure you don't overdo it such that the white background "blooms" into the silhouette.

[Matt McCoy]

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Sheldon: Here's a cigar box shaving kit I make with a foam insert. I ship these internationally and, so far, they have arrived with everything in its proper place.

Hope this helps.

[Dave Sheldrake]

Very nice Matt

[Sheldon DeCosse]

Thanks guys. I will.use your advice.

[Eric DeSilva]

I've started on a project to do this--I also found tracing and scanning (my scanner is 1:1, which helps) then just using drawing tools in AI to work for me.

For those that cut foam, have you had any problems with fire? I'm going to start the foam part soon, and have heard of some problems with both melting and fire using EVA foam. I have both 3/8th and 5/8ths I can use--will one work better?

[Rich Harman]

If you have a higher end DSLR and Lightroom, Aperture, PhotoShop or DXO (maybe other programs) you can make use of their lens correction features to correct for all manner of lens distortions.

[Martin Boekers]

Here is a video on how to add a cut line to a bit map... If your familiar with Corel you can use the contour tool to expand the outline as needed.

It's always good to have some scrap mat board around to test cuts for accuracy first...