3-Axis Milling Overview

CNC milling is suitable for machining complex 3D contours surface or solid models can be submitted as *.iges files. Files that originate in a polygonal modeler can be submitted as an .stl file.

Please recognize that the demand on our facility has increased steadily so that we need a higher level of preparation on your part to help us to meet your deadlines for completion. For best results, include the following in your planning:

Early Contact:

As soon as you have a design that you believe you will use, please consult with the RPC Staff regarding strategies for Rapid Prototyping. Bring in images on paper or screen to show us what your finished shapes and functions will be. Even if you are already confident in what model making techniques you will use, we may have some helpful suggestions and will also get a sense of how much demand you plan to put on the RPCenter resources.

Best Methods:

Sections of your model that are best accomplished without using RPCenter operations should be directed appropriately. This includes:

  • flat-panels or other shapes which could be accomplished by manual means
  • parts that could be easily purchased ready-made
  • items that should be made of materials other than those that are effectively used in our Rapid Prototyping technologies

Thorough Preparation:

CAD files for CNC milling should have all parts arranged for cutting in the 3-axis machine. Here is a quick review; appropriate preparation includes:

  • A good strategy for separating pieces of your product to facilitate tool-approach issues, including considerations for re-assembly after cutting, if needed.
  • The CAD model arranged for milling, showing exactly (and only) the parts as you want them cut, including space between the parts for the cutters to work and the foot-print of the block of material modeled in wire-frame ( see maximum milling size)
  • The material prepared as directed. Most parts will require that the material is mounted on blue foam. Please be sure to use ONLY blue foam that is in very good condition. The success of your parts depends on this foam during cutting (to hold the parts).
  • For parts which must be flipped, to cut from 2 opposing sides, refer to the pdf for setup: wheel-flip_set-up_sheet.pdf

What Kind of Materials can be Milled on the 3-Axis Milling Machine?

  • Styrofoam, rigid polyurethane foam, Renboard, styrene, acrylic sheet, various engineering plastics, machine able wax, etc.

Maximum Milling Size

  • x33 x y18 x z10 inch (838.2 x 457.2 x 254 mm) or
  • x36 x y15 x z10 inch (914.4 x 381 x 254 mm)

Important Issues to Insure a Successful Result

Checklist before exporting CAD model:

  • Position your object so that the origin is in the lower left.
  • Position parts at Z zero
  • 0.125 inches between parts and outside edge of block
  • 0.050 inches minimum between top of part and top of block.
  • If you have several objects in one file, create at least 0.625 inches space in between.
  • Make sure the scale is right.
  • No undercuts (split parts if needed to avoid undercuts).
  • Layers in your program will be exported which can be useful with understandable naming conventions.
  • Show a representation of the footprint of the block on separate layer.

Which Programs can export the right file format?

The RPC accepts the file format .iges for milling. Proven programs that export .iges files are:

  • Alias Studio
  • Rhino
  • Solidworks
  • And any other program that can export .iges files

Tutorials and Instruction