CNC Machine Tool Axis Conventions

So that it is clear what motions & components I am talking about in future build posts, I will outline here the axis conventions that I will use throughout. They are as per section 5.2.3 of Manufacturing Automation (2nd Ed) by Yusuf Altintas:

Machine tools are programmed in a Cartesian coordinate system. The Z axis is always aligned with the direction of spindle. The primary X motion is normally parallel to the longest dimension of the primary machine tool table. The Y axis is normally parallel to the shortest dimension of the primary machine tool table. Characters A, B, and C designate angular motions around the X, Y, and Z axes, respectively.

With this in mind, the axes of movement that the machine will be designed to use are X, Y, Z, B & C.

Manufacturing Automation contains a great deal of information on metal cutting mechanics and CNC design and I expect it will prove to be an invaluable resource throughout this project.

5 Axis CNC Design & Build

This is the beginning of a new project that I’m starting to design and build a 5 axis CNC machine. Computer controlled 5 axis machines are very powerful tools as they allow for complex parts to be created with great accuracy. Here’s one of the best examples I’ve seen of a 5 axis machine in action:

Typically 5 axis machines have a starting price of around £100,000 excluding tooling and software which makes them rather unattainable for small businesses or individuals. So, over the coming months I will be designing and building my own low cost machine, with the intention of using it to cut wood, plastic, brass and aluminium.

The project aims to set a new standard for the design of ‘home made’ machines by starting from the first principles of machining and using the results of numerical techniques and FEA to drive the design.

I will be releasing the plans for the final design and the techniques used to determine the design parameters and evaluate the machine’s performance to the community, so that others are able to make their own low cost 5 axis machines with confidence. I also hope to work with component suppliers so that fellow builders will have easy access to the components they require.