AXYZ 4008 retrofit – original steppers/drives + Mesa 7I95T + LinuxCNC

I’ve recently acquired an older AXYZ 4008 CNC router and am in the process of replacing the original AXYZ controller with LinuxCNC and a Mesa 7I95T.

I thought I’d document the conversion here, both in case it helps somebody else and because I’m very interested in advice from anyone who has already converted one of these machines.The intention is not to gut the machine unnecessarily. Mechanically it appears to be a very substantial router and much of the original electrical hardware looks perfectly serviceable. The aim is therefore to replace the obsolete controller while retaining as much of the original AXYZ hardware as practical.The machine is an AXYZ 4008, approximately 2007 vintage, with a roughly 3 × 2 m working area and an ELTE spindle. X and Y are rack-and-pinion driven and Z uses a screw.Motion is provided by Vexta/Oriental Motor PK299-F4.5A 2-phase steppers, rated 4.5 A, driven by the original Pacific Scientific 6410 stepper drives.The 6410s are particularly encouraging because they accept fairly conventional step/direction control. The existing AXYZ controller feeds the drives through DB9 connectors. We initially considered reverse-engineering these signals with a logic analyser, but having found the drive documentation and previous AXYZ LinuxCNC conversions, that now seems largely unnecessary.We have bought a Mesa 7I95T, which should give us considerably more I/O than we immediately require and leaves scope for additional axes/tools later.The rough architecture we're aiming for is:
 One interesting discovery has been the AXYZ connection board inside the cabinet.Rather than simply removing it, we're investigating whether it is worth retaining. It appears to handle quite a lot of the machine-side infrastructure, including limit sensors, tool sensor, E-stop-related connections and various auxiliary functions.It is associated with a substantial toroidal transformer and appears to provide several control voltages including 5 V, 12 V and 18 V.The board has conveniently labelled connections including:
 There are also connections elsewhere on the original controller for the vacuum pump, dust collection, inverter(s), ATC controller and RS485.So at the moment we're considering retaining this board as the interface to the existing machine wiring and taking the appropriate signals from it into the 7I95T, rather than rewiring every sensor and auxiliary device individually.One difference from some of the documented Mesa conversions is that the 7I95T doesn't provide the convenient 0–10 V spindle-speed output found on boards such as the 7I76. We'll therefore need a separate interface for the VFD's analogue speed command. Spindle run/enable should be straightforward using an isolated output/relay.The other area we're treating separately is the E-stop system. The original E-stop appears to have been interpreted by the AXYZ electronics, but for the retrofit we want an appropriate hardware safety chain rather than relying on LinuxCNC software alone.Our initial milestones are deliberately simple:

1. Get LinuxCNC communicating reliably with the 7I95T.
2. Connect one original 6410 drive and establish STEP/DIR operation.
3. Jog X/Y/Z correctly.
4. Identify and interface the existing home/limit sensors.
5. Implement a proper hardware E-stop.
6. Start/stop the existing VFD/spindle.
7. Add 0–10 V spindle-speed control.
8. Make the first test cut.

After that we can tackle the tool sensor, vacuum/dust control and eventually the ATC.We have already found the earlier AXYZ 4008 retrofit thread here extremely useful, particularly because it demonstrates that retaining the original AXYZ steppers/drives and interfacing them to Mesa/LinuxCNC is quite practical.I’m documenting photographs of the machine, original controller, connection board, drives, motors and mechanical drive system on our workshop site here:continuumkit.org/workshop-inventory/axyz-cnc/I'll add wiring diagrams, Mesa configuration and anything else we learn as the conversion progresses.If anyone has experience specifically with the AXYZ connection board, Pacific Scientific 6410s, or interfacing an AXYZ spindle/VFD to a 7I95T, I'd be particularly interested to hear how you approached it.