tracing an object using the shadow effect and laser cut the file

[stan kern]

this will show that placing a projected light 90 degrees to the drawing table
casts a shadow that can be traced and a dxf file created to allow a fitted foam
insert for that object using the CO2 laser to cut it


https://stankern.vids.io/videos/799eddb1161de9c7f0/tracing-an-object-using-the-shadow-effect

[Keith Outten]

That's a nice tip Stan. I will be sure to try your technique shortly.

[stan kern]

Keith
you need a good powerful light setup 90 degrees to the object, in my case i used a projector, but my ceiling being 8 foot i can only trace out small objects like say 18x18 in
I need to find a more adjustable light source

[Keith Outten]

I have a suggestion.
Have you seen the round LED lights that are made to be installed in an overhead socket?
Jackie gave me one for Christmas that I installed in my shop. It has three fan blades, each full of LED bulbs and the white light it produces is amazing. I will snap a picture of the light ASAP.

[Keith Outten]

476914
Can't take a picture with the light on because it just blinds the camera. Note that each of the wings are adjustable. The light is about 12 inches in diameter and a bright daylight color that produces way more light than a standard two bulb florescent fixture. I could easily replace all of my florescent lights in my shop with these LED's. This one is used as an access light when I enter the shop and want to go upstairs without turning on any of my zone area lights.

See my post number eleven for the picture.

[Glen Monaghan]

hmm, I get "Invalid Attachment specified. If you followed a valid link, please notify the administrator (https://sawmillcreek.org/sendmessage.php)"...

[stan kern]

can you resend the picture even with the light off

[stan kern]

also i tried a few light sources and the best was a slide projector but its the focus that giving me grief
But the slide projector light was strong and gave a sharp shadow, i would like a projected light with varying focal length
right now light at 7 feet gives me a 20x20 image on the table , would like something bigger

[Bert Kemp]

invalid file attchement

[Keith Outten]

477275

Sorry about the first attempt to upload this pic.

[stan kern]

would like to see the shadow of an object, because i feel the light has to be like a lens light that you can focus

[Keith Outten]

I will see what I can do. Moving the wings up and down may provide the adjustment you are looking for.

Been real busy working on my dune buggy's brakes. I finally got the new master cylinder reservoir installed last night and filled with fluid. I need to get the car out of my shop, it just takes up way to much space. Once its running again I can move it inside and out to accommodate the days work.

[stan kern]

dune buggy sounds great, my shop will not house any vehicle
its 3500 sq feet but i cannot get a vehicle into it, garage door is 20 in off the ground (loading bay) and there is too much equipment there
my john deer trator won't fit the shop, I need a bigger shop

[Keith Outten]

I have similar problems, my shop is three bays, 24 by 36 feet but I keep one bay open for work space and have a place for my workbench that I move around when I need the full bay for a project. I Can't get my tractor inside either the doors are only eight feet high and the ROP won't fit under the door even though I cut the top of it off so it would go in my barn. My welding equipment is in the corner by the door so I can work outside if weather permits.

Struggling with the last castle nut on the rear wheel, haven't been able to break it loose yet. Today is the day though :)

I will try my best to get the picture for you today.

[Keith Outten]

I captured two pics placed directly under my LED light in my shop. I am not sure how this is supposed to be done because my results don't seem to be very good. The light is about 7 feet above the surface and I was standing on a ladder at least 5 feet above the wooden piece. In the second picture I raised the wooden piece above the surface about one quarter inch.

478008 478009

[stan kern]

Keith
i was lucky on my first attempt, i see now that you need a projected light 90 degrees to the object and you focus on it and the shadow is perfect all around
I used a slide projector but i need one that has a variable focal length as i can only trace about 14inx14in
Or a higher ceiling
The strength of the light also helped
I am still working on finding that perfect projector 9very difficult without trying it)

[Keith Outten]

The LED light worked fine. When the piece was perfectly centered under the light there was absolutely no shadow when the part was sitting on the table probably because the light is not a point source. The three blades cast the light evenly all around the part. Raising the part off the table was the only way to produce a shadow, I think this is because of the distance between the light source and the part. As the light gets closer a shadow will develop.

[stan kern]

Yes i agree to lift the object off the table even 1/4 to 3/8 might be a better shadow effect