My breakout board does not have a spindle relay. Any instruction I have found use a board with a spindle relay. Do I need a new board?
--You shouldn't need a new board, just buy a relay board. This is the one I have https://www.amazon.com/gp/product/B07DSYTJMD (one controls the spindle, the other the laser)
My board only has a 5V input. Any boards with a spindle relay also have a 12-24V input for the PWM. Do I need a new board?
--The PWM comes from Mach3's parallel port pin usually pin 14 or what ever pin you have defined on the spindle for ports and pins. So shouldn't need a new board, it's just a pin on the BOB.
If I get a board with the spindle relay, do I connect the TTL input to the laser controller to the relay output or to the PWM ports on the board?
--The TTL connects to the PWM pin defined for the spindle on the BOB and ground.
If I get this working, can I manually turn the laser on and off using the spindle control in Mach3?
--Yes, I just got this all working on my setup with Mach3 and a gecko G540 controller.
I have my laser connected to pin 1 (output 2) for the relay to send 12v power to the laser unit. I setup a fake C-Axis so I could use the direction pin to toggle the TTL on/off, but to get this to work I had to build a "AND Gate" circuit with pin 1, C Axis dir pin, and the PWM pin. Sounds confusing but this allows me to use my current spindle and laser in the same profile with PWM/TTL control.