SX2 spindle control
Reply with QuoteHello, surprised no responses yet. I'm building up a spindle controller for my SX2 so I have some insights that might help. The macpod website has some good info on the signals that control spindle direction, and you should also search for djbird3's LMS 3900 build thread, as he also made a spindle controller and detailed the connections. I hate to add a disclaimer, but the following is to the best of my knowledge, and until I actually complete my controller, is relying upon the work of others which have successfully demonstrated control. Please read all of it before doing anything. If you are not comfortable and/or it doesn't make sense to you, err on the side of safety and don't take unnecesary risks with your equipment. On the positive side, others have done it, so you should be able to get there too. Edit: The first thing to do is email CNC4PC for additional info, they seem to be very responsive and should be able to give expert advice for obvious reasons.
In looking at the C11GS, you will need to provide a separate 12 Volts DC supply to connector X1. This is a separate power supply, such as a wall wart. The analog output pin X2 is what goes to the SX2 spindle controller pot P2. P1 of the pot is connected to the 12 volt ground. The SX2 pot is set up for 5 volts, SO YOU NEED TO MAKE SURE TO ADJUST THE VOLTAGE ON THE OUTPUT X2 TO 5V OR LESS BEFORE CONNECTING IT TO P2. Once you set up Mach3 to control the spindle with PWM on pins 14, 16 per the manual, hook a meter up to the output X2 and 12 Volt ground, turn on the 12 Volt supply, and set up Mach3 to control the spindle, and set the output for maximum spindle speed. Adjust the C11GS pot X3 untiul it is safely below 5V. Now, this is where my knowledge gets sparse. Because the SX2 pot is built into the board where the connectors go in, there is no easy way to disconnect the pot pins P2 and P3, so if you connect to those directly you will be feeding the pot in parallel with the SX2 reference voltage. Personally, I would do this: 1) disconnect the main input connector (10 pins) from the pot board. 2) Per macpod's wiring diagram, release the spindle control pin (he shows it as the red wire labelled Analog input from the connector housing. This is a crimp pin with barbs to hold it in the housing, so use a small screwdriver or the proper tool if you have it to get it released 3) plug the connector back into the board 4)Connect the analog output from the C11 X2 to the red wire, and connect the 12 volt ground to the pot P1. With everything connected, you should be able to power everything on and control the spindle speed from Mach 3. AGAIN, PLEASE DOUBLE CHECK THE ANALOG OUTPUT PIN WITH A METER TO MAKE SURE THAT THE VOLTAGE ALWAYS STAYS BELOW 5V ACROSS THE COMMANDED SPINDLE SPEED RANGE BEFORE HOOKING UP TO THE MILL CONTROLLER. IT WOULD BE A GOOD IDEA TO MARK THE POT WHERE YOU READ 5V ON THE METER, AND START WITH THE VOLTAGE LOWER. ONCE YOU GE IT CONNECTED TO THE SX2 CONTROLLER, YOU CAN TWEAK THE POT TO MAXIMIZE SPEED, BUT BE CAREFUL. THE SX2 INPUT BE FAIRLY TOLERANT, BUT NO SENSE TAKING CHANCES.
If you get this working ok, controlling the spindle direction should be much simpler by using the relays to connect the forward and reverse pins to the center ground pin of the 3 pin header. Use one relay to connect forward to ground, the other to connect reverse to ground. The relays are just electronic switches so the worst that can happen is the controls are reversed if you get it backwards.
Hope this helps, maybe others can chime in too. --md
Originally Posted by mduckett
