Chester Cobra milling machine (CNC converted)


This machine was bought new in 2008 and has only been used to convert it to CNC and test it out. It works very well and because the conversion does not involve modifying the existing parts it can be put back to the original machine if you wanted to and standard replacement parts are available as the standard machine parts are.


Now that I have made the conversion kit I am looking to sell the machine to recover my costs. I am looking for £700 which is what it has cost me. You will need a suitable computer and software to run it. I can supply the computer and Mach 3 software (shareware version limited to 250 blocks of code) all set up as shown in the photos for an additional £75 or you can supply your own.


I can also make and supply the motor mounting kits to order if required.


Feel free to phone me on 07854500851 and ask for Bob or contact me through the Contact Us page.


Photo Number 12 shows the word Triumph Logo engraved into a piece of aluminium.


To see machine in action go to the youtube link below.


Standard machine features.


Dovetail column.

The variable speed control and gear drive. No belt changes necessary! 

Precision machined table. 

45deg Tilting column.

Safety shut off switch.

Adjustable depth stop.

Fine feed head control.

10mm drill chuck.


See full machine spec of the standard machine on Chester machine tools web site


CNC Conversion Features

Converted using the machine standard leadscrews.

3 Axis 2.5 amp bi-polar stepper motor controller

3 x 1 N/M stepper motors (Dual Shaft).

Adjustable backlash nuts on X and Y axis as standard on machine.

Adjustable backlash fitting on Z axis.

Handles fitted to stepper motors so can be used as normal milling machine.

Original standard machine axis dials fitted to conversion and clear plastic motor covers fitted so dials can be seen through covers.

PC supplied with machine

Tower PC.

17” monitor. Keyboard and mouse

AMD 2400 mh processor.

512 Mb Ram.

80 Gig hard disk.

CD writer.

Card reader.

Complete with Mach 3 software (Unregistered Shareware version)