CNC Router project

I’m planning to build a CBC router and wonder what stepping motors and controllers would be suitable ?


Hi Mal,

Welcome to the forum!!

A CNC is a pretty complex system with many parts relying on the others. A good start would be to size up your system:

  • How fast do you want the mill to move?
  • How much do you want the carriage to weigh?
  • What kind of materials will you be milling?

As an intermediary step, it might be worth making a pen plotter to hone in on using stepper motors.


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Hi Liam. The functional questions are legit ones that need to be answered within the project.

As far as the mechanical build is concerned I have very well developed capabilities. My apprenticeship was at Vickers dockyard in fitting and machining. I worked on submarine refits and steam turbine rebuilds. I also have a well set up workshop with a lathe and mill.

This machine will utilise linear motion bearings and ball screws as well as high precision in its setup.

A big early question will be exactly what size motors and what equipment to use as power supplies, drivers etc.

This machine will be to rout guitar bodies and necks. It will do the carving for both as well as drill holes for components such as pickups bridge tuners.

The motors and control equipment can be bought any time and set up on a test bed to run.


Hi Mal,

Sounds like an awesome project :smiley:
With any mechatronic project sizing the actuators is an optimization problem, you could go with something that you calculate to be the most minimal solution or get something that could fling your mill to the moon. With some rough estimates on required torques and speeds you can then move on to grabbing motors. Liam had some good starter questions but some others would be… Do you want an open or close loop system? What controller were you looking at using and what features does the firmware offer (this effects the driver choice)?

No doubt about your level of skill here at all! Core has some larger stepper motors such as this one but if you are after something that can rip through wood then I’d be taking a look at something that can deliver a lot more power. FYI you can overvolt motors BUT be sure to keep the maximum current well within spec, this will increase the speed but not torque


Hi Mal,

Sounds like an awesome project! if your CNC is on a similar scale, I’d check out Marco Reps’ build playlist on YouTube, here’s his episode on a fancy servo system he picked up:

It’s above my head engineering wise (only just worked out how to build a decent 3D printer, let alone something designed to cut steel with micrometer precision), but I hope this gives you something to stew on (or at least entertainment)


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Thanks James

Thanks Liam

A more detailed answer to your comments on my project. I’m currently drawing on the experience of a number of people to see what they have done in their build.

One guy in America is onto his fifth machine build for his guitar building business. He exclusively uses rack and pinion to move the router. The drive pinion is pushed onto the rack with a spring to minimize backlash. From a mechanical perspective I don’t like this as gears need a bit of backlash to minimise wear. Also each drive needs a reduction gear for fine movement. Without a reduction each step would give about 0.3mm accuracy. Not so good. With the reduction gearbox he gets about 0.02 mm per step.

I’m not sure this is a great way to build this as a ball screw with direct motor drive can give about 0.015mm per step.

This guys next build will use Nema 34 steppers that deliver 1712 ounce inches. A monster of a motor.

The first step will be to consider what size machine to build. I want it to build electric guitars. This involves carving necks and bodies. Realistically this machine needs to be sized to make these two components. Whilst there’s a temptation to make it larger what limits should I place on it.

Much to consider

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