Week 6: 3D CAD 4 Axis CNC

CAD model of enclosure
What Not To Do Clock in CAD

We will model enclosures in CAD and then cut them on the 4 Axis CNC.


3 Axis

Became this piece.

A 3 axis CNC can move in the X, Y, and Z axes.  Typically, no undercuts or double sided parts.

X Axis – The left and right direction on a CNC.

Y Axis – The front and back direction on a CNC

Z Axis – The up and down direction on a CNC

What parts can be made on 3 axis CNC


4 Axis

The 4 axis mill can do everything an X, Y, Z mill can do plus it can rotate the material (A), this is the 4th axis.  The way the rotary axis works is similar to a lathe.

The 4 Axis mill can mill in the round…

or can do double sided parts.


Flat Stock

Two sided parts made from flat stock.  All of the roughing and finishing is done to one side of the part, the stock is rotated 180 degrees, then the other side is roughed and finished.  Tabs will often be added and there is a faint seam line left after machining.


Round Stock

Full rotational parts can be made from round stock.  There is a full roughing stage, then a final finishing pass.  These often take longer than two-sided parts made from flat stock.  Tabs can be added to the two ends of the part.

Whatever the shape of your stock, there needs to be extra material at the ends of the part.



Parts will always have tabs.  They can be designed into the part or the CAM software can add them.


Center Holes

Just like a lathe, the 4 axis has a live center and a center hole must be made in the material before it is mounted.



We will need 3D models to work with the 4 axis.  An .igs or .stl file is ideal.

Intro to 3D CAD Intro to 4-axis mill



We will be using Roland’s SRP Player for the CAM.

This where you will select material, set the size, create the tool paths, and get a time estimate of the job.


Machine Interface

VPanel for Modela Pro II is the interface you use to set origin, jog the spindel, and work directly with g-code.  For now, we will not use g-code.


Setting Origin

The mill remembers origin, even after it has been shut off.  Most of the time, you will only need to set X origin and Z origin in relation to the bit.


Length of Job

These types of jobs usually take a very long time (hours).  Check the length of a job before beginning.  You can NOT leave the machine unattended.

There is a pause button, but you must also stop the spindle from turning.


Saving Time

Always prepare your stock material as close to the ideal dimensions SRP Player gives you.  A few minutes on the lathe or the miter saw can save you many minutes (possibly hours) on the 4 axis.

The ideal dimensions are on the right in parentheses.

Thick Tabs

If your design can allow it, the thicker your tabs are, the shorter the time to mill them.

Editing Tool Paths in SRPlayer

This video gives a detailed description on how to do this (at the 6:20 mark).


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Almost all of the CNCing is done. Soon back to the lathe.

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Became this piece.

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4th times the charm

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Related Reading/Viewing

Roland MDX-540

Users manual for MDX540

User’s manual for the ZCL-540 rotary axis unit

Tutorial guide for SRP Player Pro software (pdf)

SRP Player Workflow (video)

Vectorworks Loft Surface

Vectorworks Deform Tool

Vectorworks Create Helix Spiral

Vectorworks Oval Tool

Vectorworks Fillet Tool

Vectorworks Cone Tool

Milling Time: Testing the Roland MDX-540 4-Axis CNC

Convert obj Files to stl