How to Make Almost Anything > John's class Homepage > The NC Mill

The NC Mill: It Could Kill You

This 6^th assignment we are to design something simple, import it into FeatureCam, and machine it with the NC Mill.

I designed a test block that I hope will fit with Lego blocks. My idea is to copy the top and bottom of an existing Lego block and make them as two separate pieces. My hope is to get the specifications right, design a 2^nd generation with a hollow inside for electronics, then use this with Legos as part of my final project.

I measured 3 Legos blocks. Here are the dimensions as scanned in from the paper towel I wrote them on:

I drew them in Blender. The trick to making the knobs is the Dupliverts command. This allows creation of multiple objects w/ a set geometry. Scaling of the objects and their place can be done independently. At the end, the entire deal can be turned into separate meshes with <CTRL><SHIFT><A>. I may redesign my microphone sensor stand (see 3D printers) with this technique.

After creating both blocks in Blender, I did Boolean union ops to turn it into one object. This created too many polygons for Featurecam to handle. I used the Decimate command in Blender (F9) but this destroyed the integrity of the object. So we ended up importing into Featurecam as many separate meshes.

Featurecam:

• Creates a new geometry from the DXF file you import
• Import 2D objects
• Featurecam has to recreate the objects to be a geometry it understands. This is easiest done by converting to curves.
• Feautrecam does well with Omax DXF files.
• With each curve, you can choose how far in a pocket Featurecam should make the object.
• Set tolerance to 0.
• Islands are what to take out inside, boundries are what to take out outside.