I am using pins 2-9 for Step/Dir on the 4 drives.
Pin 1 is for the charge pump (not yet implemented but planned)
Pin 14 is for drive enabling.
Leaving only 16 and 17, Ideally 1 for Spindle and 1 for coolant.
As I am having trouble with pin 16, I have both relays connected to pin 17 so the coolant comes on whenever the spindle comes on. It is not ideal but it seems to be working OK.
It would appear that the fault does not lie with pin 16 - which, I assume, switched the spindle on and off correctly, but lies with the "dir" pin for the axis in question.
Can you elaborate on that? Why would the dir pin affect it? If I stop using pin 16 altogether then the problem goes away (or at least has not shown itself since disconnecting that pin)
You say that you press F5 - so I assume this must be set up on your system hotkeys. Check on your system hotkeys set-up and make sure Pin ?? is not inadvertantly set up to also react to F5. (Or indeed on someother program that may be running in the background - although to be fair pins 2 - 9 were only data pins if used with a printer)
F5 is the standard key for spindle on. I have not modified the system hotkeys from the standard install.
Does the fault occur if you use the mouse on the screen
Yes, if I press the screen button then the fault occurs. (while pin 16 is connected)
I did do a complete strip down and rebuild when I added the 4th axis including completely rebuilding the electronics enclosure/wiring etc. The original system was using the onboard LPT port and I had the same problem. I have installed a separate LPT card now and the problem is still there. I can only assume it is some sort of interference problem on the StepMaster board or within the driver system of the PC.
Hindsight is a wonderful thing. Whilst the StepMaster is a great little card, I appear to have outgrown it quite quickly! When I first started I didn't want the 4th axis, coolant/spindle control or a charge pump!