Relay to turn on spindle

OT-CNC wrote:

I hooked it up to the normally open side and as soon as I turned the power on the mill the spindle started. After I booted into linux cnc the relay opened and the spindle stopped. The normally open side is closed untill there is power. And I don't see any jumpers on it anywhere

That sounds like you wired it normally closed? Try the other terminal on that BOB. Maybe it's mis-labeled. Is this your board?? I would check with a volt meter to confirm the state of that relay when everything is powered off.

Yes that's the board. If the USB is plugged in(board powered ) the normaly open terminal is open . As soon as I turned off the board it closes and the spindle starts.

With the other side it is opposite. I'll double check everything later today.

They way it's wired currently the spindle starts and stops the way it should as long as the Bob is powered. You can hear the relay click at power up and the LED lights up

Yeah, that sounds reversed. You want it off and stay off until linuxcnc is in control.

OT-CNC wrote:

Yeah, that sounds reversed. You want it off and stay off until linuxcnc is in control.

If I reverse it it will run as soon as the Bob is powered up. Something is screwy

Ok, it looks like I did have it on the normally closed terminal.

So something is making the relay close on start-up. I'll have to investigate more

Ok, if I unplug the parallel cable from the computer the relay turns off.

This doesn't make sense.

This is with the computer off and the USB power wire plugged in. As soon as the parallel cable is plugged in the relay closes

I inverted the pin for the spindle and it looks like that was it.

After unplugging the parallel port it must have reset because as soon as Linux cnc was starting it closed the relay

andypugh wrote:

Try a different parallel port pin. Some are hardware-inverted, some are not, so the default state (before LinuxCNC takes control) varies from pin to pin.

The documentation with the board says it uses pin 14 for the spindle relay.

After I inverted the pin in is seems to be working