Chris Lomont's Laser Cut Torus Page
Published
A laser cut torus
<img alt="Small pieces" height="630" src="Screenshot.png" width="708" class="style1" /><p>
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<img alt="Code" height="802" src="Code.png" width="874" class="style1" /><p>
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<p>I wanted 32 slices for my wife's 32nd birthday, and I wanted to use
1/4" wood, since that is about as thick as the laser cutter cuts. I wanted
the inner hole to be the size of a tube in case I want to nest some (plus
I find that ratio pleasing). I also wanted the final item to be roughly
square gridded, meaning the gaps and the solid parts should be pretty
close in size. This leads to an outer dimension of about (16*2+1) *1/4 =
8.25", a pretty nice size.</p>
<p>So the code takes the values from the sliders, walks the corresponding
torus in constant x slices, and for each slice uses the equation for z in
terms of y and walks y in 1/100" increments, computing a list of z values.
The values are stitched together along the top, and the bottom has notches
inserted where the corresponding slices should go. The result is cleaned
and written out to a DXF file. All this is done in custom code since I
don't know how to make such things in any solid package (although someone
probably does). <a href="MakeTorusDXF.zip">Here is the zipfile</a> of the
VS2010 project files.</p>
<p>This above values led to the various radii. Tweaking was needed to ensure the outer
lips were thick enough to hold the pieces together. Here is the resulting<a href="TorusFinal.dxf">
DXF</a> and <a href="TorusFinal.cdr">Corel Draw</a> file. The DXF is
pretty spaced out so you'll want to edit it. The Corel Draw file is for a
12"x24" piece of 1/4" wood. Each file creates enough for 1/2 of the final
torus, so you'll need to cut two. </p>
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<p>To keep the pieces snug, I used wood glue. The gluing of pieces has to be
done very carefully and in a precise order to ensure all pieces are snug.
The rough idea is to assemble the shape without glue so the pieces are all
held in a good position. Then glue the first 4 above since they rest on the
lowest surface. Once they are dry, glue the top layer of pieces to only
those 4 cross pieces. Once that is dry, turn over, and glue everything. </p>
<p>The order is to make sure you don't glue any pieces that are not fully
snug and held in place by gravity.</p>
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<div class="boxed"><h3>Final</h3>
<p>Here is the final result, and my wife's birthday present.</p>
<p><a href="Finished1.JPG">
<img alt="Finished torus" height="480" src="Finished1_Small.jpg" width="640" class="style1" /></a></p>
<p> </p>
<p>I made two matching torii, one for each of us. People at work saw my
prototype and liked it so I decided I'd like one for my desk also.</p>
<p><a href="Finished2.JPG">
<img alt="Finished 2" height="480" src="Finished2_Small.jpg" width="640" class="style1" /></a></p>
<p>Here are the two final ones and the initial prototype (the wood of
which is missing parts, is cut funny, etc.).</p>
<p><a href="Finished3.JPG">
<img alt="Finished 3" height="480" src="Finished3_Small.jpg" width="640" class="style1" /></a></p>
<p> </p>
<p>That is all. I hope you enjoyed this, and happy hacking! </p>
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