CNC Machining, Mold Making and Resin Casting

The best guide to CNC Machining, mold making, and resin casting that I’ve found online is over at It is thorough and detailed, and definitely worth studying.

CNC machining (computer control milling) is a “subtractive” method for processing raw material with a drill-like rotating cutter with computer controlled movements of the cutting head.

Michal Zalewski points out that if you can make a mold using CNC milling, the cost of making a small part out of high strength,
engineering grade plastic or tough rubber, is extremely cheap.

He gives practical advice on buying a CNC machine – important factors like mill rigidity to take into consideration.

The part on using resin casting to make the part is excellent too! Go read it!

Casting Metal Parts from 3D Prints

There is a good series over at AdaFruit about Casting Metal Parts from 3D Prints. I have done a similar thing but casting pewter from a 3D print of a birds skull. It turned out quite well, although I discovered how important it is to properly “finish” the 3D print. The next time I do this I will sand and paint the print to smooth it before casting. I definitely want to get better at this kind of thing.