CNC Routing for Beginners

New to CNC Machining?

Many of our customers who are new to the CNC Routing process ask a lot of questions such as how do I load the STL file to rout the part, or what bits do I use etc. In the most basic of terms, there are 3 components involved in CNC machining. The CNC Router Hardware, the controller software and the 3D model.

The CNC machine you choose is entirely up to the user, but here are some helpful hints below, to get you going in the right direction. 

Workpiece Platform or Bed: Minimum size for any guitar, ukulele or mandolin work is 24” x 36”. This size is often referred to as a tabletop CNC.

Frame & Rail Stability: This depends of the accuracy of the part that is expected from the customer. If you intend to rout fret slots, intricate inlays or expect highly accurate routed pieces, consider a solid steel frame. For most guitar work and non-professional work, other materials such as aluminum would likely work.

Axis Movement: Minimum of course for most work is 3 axis, that is X, Y and Z. For more access to contoured and angled drilling you will need the 4th axis. This allows the spindle to tilt to undercut surfaces, drill angled tuner holes in the peghead etc..

Bit changes: Different bit shapes are required for doing different types of routing. 

Controller Software: This is the software that you load you STL file into, set the stock size, position the workpiece, re-size the part if needed. You also can set the outside vector or vector offsets for the piece, set roughing and finish tool paths and outside cuts. If you are doing 2-sided routing you can set up registration holes with this software as well.

The YouTube videos below will give you some insight as to the steps required using Vectric Aspire. Vectric V-Carve Pro will have many of the same controls. When everything is setup, you can run the G-code for the part and load it on a memory stick or send it directly to the CNC, depending on your setup.

If you have technical questions on your controller software, you should contact your software reseller or tech support. 

Note: For techniques for 2-side routing, stock setup and much more, check out videos on YouTube under CNC routing guitar.

Router Bits: Usually contoured areas such as for an archtop guitar or F5 Mando top will require a ball-end bit. For holes, pockets and roughing cutting a flat bottom spiral bit is the best bit. Specialty bits are available for fine work such as fret slots, inlays etc.. For cutting forms, templates and most of our Guitar tools, a 3/8” and 1/8” spiral down-cutting carbide bit is best.  

Fret Slot Bit

Spiral Cutting Bits & Ball End Bits

My CNC machine is a Laguna I.Q. which has a 24” x 36” bed, heavy steel frame and 3-axis movement. I use Vectric V-Carve Pro for the controller software. There are many other capable programs out there such a RhinoCAM, Fusion 360, Aspire etc.. The videos below are from Aspire, but the basic setup and part handling will be very similar.

How to carve a STL file with Vectric Aspire Part One

How to carve a STL file with Vectric Aspire Part Two

Also, additional information that is available to the beginning CNC woodworker is available on CNC Sourced