PWM Spindle Control

Do I need to proceed with connecting the spindle control if I have a DeWalt ?

I have my quiet cut 400w dc spindle just connected to it’s own power supply and turn it on and off manually.

You cannot control the speed of your dewalt with PWM.

Some people use the spindle control signal to control a Solid State relay to turn the DeWalt on and off via G-code.

If u want to control on and off with gcade, get a lot relay of Amazon. Easiest set up.

I believe that would be I(Eye) for (I)nternet (O)f (T)hings relay…

As stated you can not drive a DW611 via the PWM out. You’d need something else in between to take the PWM out (0~5V) and translate that from either 0~110V or 0~220V. This is exactly what the SuperPID is designed to do.

There are two pins on GRBL. Spindle Enable and Spindle PWM. Spindle Enable is exactly that. Spindle On/Off. Spindle PWM is for Speed control. Some spindles will fire up with only the PWM out from GRBL. 0v being off and 5V full power. Others need the Enable pin set to high and/or the PWM to set the speed.

In the case of the using the PWM with a SSR/Relay is not advised. If in your post processor you say M3 S9000 then GRBL is going to send the matching PWM signal. Which in turn case the SSR/Relay to pulse as the rate it’s commanded. i.e. you will hear a high pitch whine from a SSR or a rapid clicking sound from a standard relay.

If the end result is to simply fire up the DW611 (or any router)- Use Spindle Enable. If the end result is speed control, Then you need a device like a SuperPID and give it both the Enable & PWM pins (with a 5V ref.)

Can you trigger more than 1 SSR with the same signal - daisy chained together? Any additional isolation, etc. needed?

I’m still waiting for my X-Carve to arrive but I’m planning how to control the DW611, vacuum and maybe even a deep water aquarium pump (as an air blower) at the same time.

You can absolutely do that. The input of an SSR consumes very little current. However, if I could make a suggestion, it’d be better to connect 24VDC + to the + input control terminal of both, the - input control terminals of both together and to the drain on an N Channel mosfet, the source of that N Channel mosfet to 24VDC -, and the gate of that mosfet to the PWM signal from your Arduino. If you connected the PWM pin directly to the input of both SSRs, you run the risk of one failing (as SSRs, especially cheap eBay/Amazon SSRs, tend to do from time to time) and drawing more current than your Arduino can handle, destroying your Arduino. The mosfet will draw zero current from your Arduino. You could use a single 1 amp fuse between 24VDC + and the inputs of the SSRs if you really wanted to get fancy, ensuring that under no circumstance could you damage your 24VDC power supply. Any N Channel mosfet will do, like a common 2N7000 or a much beefier but barely more expensive IRFZ44N.

Here’s a schematic for you

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A simple solution is the IOT Relay: