Biesse Rover 342 LinuxCNC retrofit

I caught this on a recent fishing trip:

A Biesse Rover 342 wood router / machining center.

The machine came with a native CNI controller, based on 68881 and Z80. There are 2 spindles with some variant of ISO30 taper and a 10 places tool rack / changer. Additionally, the machine has a gang drilling aggregate with something like 50 positions, 10 of which are pernpendicular to the z axis, 6 parallel to X and 4 parallel to Y, one "Schlossaggerat" for milling lock pockets (?) into door blanks and one additional axis that can be outfit with another drilling aggregate or a circular saw.

Work-Area is something like 3100×1350×100mm. Max speeds are about 80m/min for X axis and 60m/min for Y axis.

The CNI controller had to go. Interface was awkward, even the floppy format was proprietary. No network interface, therefore no straightforward possibility to transfer programs to the machine.

I decided to retrofit the machine with a LinuxCNC based controller. Hardware (for now) is a RaspberryPi running some version of Linux RT-PREEMPT kernel. LinuxCNC connects to a Mesa 7i90 via SPI. The Mesa 7i90 connects several other 7i90s via RS422 smart serial (7i44) board. Axis are interfaced with a 7i48 card, servo controllers take standard +-10V speed signal. Encoders for position feedback have 12V differential quadrature + index signal, some resistors drop the voltage to levels appropriate for the 7i48.

All in all there are about 120 outputs and 100 inputs. Original wiring was kept, I designed custom input/output boards to interface the legacy input and output boards to the 7i90 cards.

Some initial kinks with strange bitfiles for the 7i90s were easily resolved, all in all the solution with the Pi works pretty well.

The LinuxCNC forum and mailinglist is very friendly and helpful.

Some links:

• circuit diagram Circuit Diagram
• custom input board
• custom output board

Status:

Machine is working with one spindle and manual toolchange.