CNC Engraver

New PCB Mill!
This page shows the the retrofit of a small CNC Engraver from a Commodore 64 control system to a current Step/Direction controller using an IBM compatible computer.

June 2002 I aquired a small professionally engineered CNC Engraver from a friend that was not able to use it. This is a factory made mini mill, that is very well made. The engraving cutter is a 12VDC dremel style of rotory tool. The steppers are 7.5 degree 12VDC motors. There is an optical sensor for both the X and Y table (currently not used, but could be used for limits sometime in the future). The controller was for an obsolete computer system known as a Commodore 64.

July 2002 the controller was torn apart for parts, and the remainder tossed out. The mill was disassembled to expose the wiring connections. All the wiring is labeled and should be very easy to connect to the Step/Direction controller I am using.

January 24, 2002 - disconnected motor wires from old control interface. Mapped out the wiring of the steppers and connected the appropriate wires to +12V. Soldered the motor windings to a new Piker4X stepper conntroller. Wired the motor spindle directly to Aux1 relay driver so the motor will come on under software control.

January 26, 2002 - completed all electrical connections from the Piker4X to the little mill. Had a bit of trouble connecting an IBM laptop running CNCPro to the Piker - turns out the IBM uses port 3BC instead of the standard 378. Once it was changed the mill fired up! I am getting feed rates of 10 inches per minute which should be great for PCB's (6 ipm cutting, 10 ipm moving!).

IBM 365XD Controller!
Assembled an MDF base unit to house the Piker4X controller, wires, switches, power supply, etc. I even had room for a small drawer to store bits. The base is 22" wide, 16" deep, and 6" high.

Inside Of The Chassis
February 1, 2003 - completed assembly and painting of the base unit. The little PCB Mill is now complete. 3/4 inch MDF was used for the base construction. A Piker4X is the "guts" for the controller. The Piker4X controls the spindle cutter, and even a piezo alarm to alert me when the job is finished!. This machine is capabable of 10 inches per minute, and works great!

Another Shot Of Mini Mill
The base features a storage drawer, large 22x16" work surface, all painted a metalic green to match the engraver parts.

April 20, 2003 rewired the control to the spindle to have the +12VDC motor run through a relay to increase RPM's. It was going through a TIP120 that was reducing the voltage and limiting the current slightly. Now the TIP120 drives the relay and the relay turns the motor on with a full +12VDC - much better!

Engraving Stock Hold Down!

The above stock hold down is used to quickly mount thin material (aluminium, brass or plastic multicolor plate) for engraving. It is easily removed for other operations. In the photo, you can see an aluminium name plate about to be engraved. I use these tags to identify my wood working projects and use them for keytags, tags for identifying gasoline mix (how many gas cans can you own anyways) and any other small tag requirements I have. You can see the plexiglass jaws (one side is cut perpendicular, while the other is angle cut to pressure fit the stock) that are easily adjusted by the four brass wing nuts.

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