Ok, i got tired of having to flip the Spindle switch all the time and decided it was time to get Mach3 doing its job!
I have a newer version of the Chinese CNC 3020T-DJ with a black controller box and the controller board is model JP-382A and the spindle board is JP-1482.
The controller has a PWM output and the spindle board has a PWM input but they are not connected. Here is some pictures i included on another post..
After i got done adding home switches to the controller i also started to trace out the boards to figure out the Spindle control.
You need two JST-XH connectors to make the interconnect cable, also if you want to add limit/home switches its the same 4 pin JST-XH connector, look on eBay for LiPo balancing cables and connectors as they are used in the LiPo battery packs.
Note... I don't yet have the PWM speed control working, still finishing up how to set that up, but i DO have Spindle On/Off control now from Mach3! The PWM control just wasn't as big of a concern for me as i generally run it full speed all the time for PCB milling.
Ok, on the controller board the jack marked PWM i numbered them from the back panel forward, pins 1-4.
1. LPT Port Pin #17 to Spindle Controller PWM Input
2. +5v from Spindle Controller to the EL817 labeled DDO, This is Spindle On/Off
3. Ground from Spindle Controller
4. Spindle On/Off
On the Spindle Controller board i labeled the pin numbers Left to Right looking at it from the front panel, pins 1-4.
4. Spindle On/Off
The front panel Spindle switch only switches a ground on the Spindle Controller and its in parallel with an Optocoupler, part number EL817, on the Spindle Controller board. So you can leave the front panel switch for manual control and leave it in the OFF position to allow Mach3 to turn it on and off.
You need to make a cable so that its matching 1-1, 2-2, 3-3, 4-4, using the pinouts as i described them. The plug orientation is flipped, so pin 1 on plug on one end of the cable would be the opposite side of the plug on the other end. You will understand what i mean when you look at the jacks, the controller board has its jack going front to back with the keyway to the left and pin 1 towards the back, but the spindle board has its jack going left to right and keyway to the back and pin one on the left. So the cable is a flipped crossover config.
Set Mach3 for Active Low on Pin #1 to turn the Spindle On/Off.
Set Mach3 to control the Spindle PWM using pin #17
Now, as i said i haven't hooked up and configured the PWM control to pin 17 yet, so all i wired up was three pins between the boards, i didn't install the wire from pin #1 on the controller to pin #1 on the spindle controller, thats the PWM control. You need pins 2-4 for On/Off control as the Spindle controller board feeds +5v back to the controller board via pin #2 to run the Optocoupler labeled DDO, the output of which toggles another EL817 optocoupler on the Spindle board that then enables the spindle motor, the front panel switch is wired in parallel across the Optocoupler on the Spindle controller board which gives manual control and can be left in place.
Here is some schematics i drew up quickly... Notice that pins i didn't continue to trace out for PWM on the Spindle board or the ENO Opto on the Controller board are marked unknown. Also in the case of the EL817 marked ENO on the Controller board note that Pin 1 of the component was clipped and bent back at the factory, ENO looks to have something to do with the A-Axis as its connected to one of the pins of the four pin header marked A-Axis, i didn't continue tracing that out as it wasn't necessary. Also pin 2 of ENO dead ends at a set of open pads on the back side of the board, i would guess there should be a 330 Ohm resistor there as they kept the same basic design across the boards, using a 4.7k pullup resistor to 5v on pin 1 and a 330 ohm resistor on pin 2 on the others for what i would assume is current limiting through the optocoupler.
Attachment 250418 Attachment 250420
Anyway, with a three pin jumper you can make the Spindle On/Off control work with Mach3, or whatever software you use, but i haven't got the PWM config working just yet. I would assume it requires removing the front panel trimpot from the circuit, either just unplugging it or installing a jumper as in the other versions of these boards but i don't have that info yet.