The Masterwood Speedy 207 seemed to be a popular machine used in the woodworking industry for panel proccessing (cabinet boxs). The machine is reffered to as a rail and pod point-to-point boring machine. It has multiple vertical spindles for drilling and a horizontal spindle with a saw for grooving and a horizontal spindle for drilling dowel holes. It is not designed for 3D milling as its Z axis is moved by an air cylinder and has finite stops for depth control.
To make this machine into a more traditional CNC router an additional motor and drive is needed for the Z axis. I would also like to replace the spindle motor with one allowing for automatic tool changing.
The control electronics is not suitable for my needs so I will be replacing it with a PC and touch screen monitor.
There are significant advantages in a CNC router build from an existing machine rather than starting from scratch. The base is very sturdy with the X axis rail mounts machined to tight tolerances, sturdy gantry with the Y axis rail mounts machined. The ball screws and nuts have mounts and brackets already provided and of industrial duty. In my case I have correctly sized servo motors, encoders, mounts, pulleys, belts, drives and power supply all made to fit the machine.
The major disadvantage I see in converting an existing machine is that the working envelope is fixed, my model has about a 3' x 5' working area and about 6" of space under the gantry (Z height) these specs are not easily changed.
The choice to convert a machine also hinges on the delivered cost of that machine. Machines of this class are increasingly available for good prices as factories close or modernize or when repairs to the machines become to costly.

Sunday, January 23, 2011

Identify machine interface components

In the beginning I think I will use the interface boards that came with the machine. I could emulate the bus of the original machine or attach to key places on the boards. Having the machine and/or computer schematics would be very helpful for this but since I don't have any documentation I will have to make do by identifing the components looking up data sheets and reverse engineering the design.
 I plan to use an FPGA (field programmable gate array) to replace the low level controls then connect to a PC for the user interface. The FPGA will provide lots of  i/o so I can have multiple data buses and control signals to connect to these boards.

The two boards account for the total interface between the computer and the electrical devices.

One D connector per axis (X and Y)
Each connector has an incremental encoder inputs (A,B,0)
+/- 10volt motor command out, and three discreat signals.

TLP 2601 isolated line receivers seem to be used
for the encoders, there is a AD7237 A to D converter which would be for the motor command.
This board provides 24 inputs and 24 outputs.

This is the original control computer. 68000 based with a flat screen monitor and 3.5 " floppy drive.


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