OpenSCAD

My First Design with OpenSCAD
Let's look at a simple example using OpenSCAD. A rectangular plate with screw holes in the corners:



So how do we produce that?

Step 1. Install OpenSCAD.
Visit http://www.openscad.org/downloads.html and follow the instructions to download and install.

Step 2. Designing.
Once OpenSCAD is installed and you've started it up, you'll be presented with a set of blank panes. Let's whack the following into the left hand pane:

difference {

// Plate size overall square([75,100]);

// Screw holes translate([6,6,0]) { circle(2, $fn=50); } translate([6,94,0]) { circle(2, $fn=50); } translate([69,6,0]) { circle(2, $fn=50); } translate([69,94,0]) { circle(2, $fn=50); } }

What does all this mean?

Difference
http://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling#difference

difference {

Subtract the intersections from each other.

Square
http://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#square

square([75,100]);

Draw a square that's X=75mm and Y=100mm.

Translate
http://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#translate

translate([6,94,0]) { circle(2, $fn=50); }

The object in the perenthesis will have it's origin at X,Y,Z. As we're drawing in 2D we don't care about Z so this will always be zero for this case. The origin for our circle is X=6mm and Y=94mm.

Circle
http://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#circle

circle(2, $fn=50);

The first parameter is the radius, not the diameter of the circle. The second parameter provides a higher resolution when drawing small circles.

Step 3. Tweak and update
Make changes to your design, and then hit F5 to refresh the rendered view of your design.

Step 4. Save the damn design!
Once you've got a design you're happy with, save it to disk before moving on.

Step 5. Compile, render and export.
Now it's time to compile that so that we can export the DXF. You can do this by:


 * Hitting F6
 * Using the menu Design -> Compile and Render (GCAL)

Now we can select Design -> Export as DXF. Select a sensible file name in a location you'll remember.

That's our OpenSCAD work done. At this point, we can make changes using Inkscape or go directly to sending it to the cutter.

Nut Traps / Hexagons
Makes a perfectly snug M3 nut trap, loose enough that the nut can be placed by hand, but then snug enough that I can bang the object on my table and the nut stays in place. 5.5mm edge-to-edge is the size of a m3 nut.