Hey Bob,
Yes.
Yes, if you have a DC load that sucks a high current and is operated at 36 Volts.
If you look a the Onefinity CNC Controller Schematics and search for the string “load_”, then you see the pins “load_1” and “load_2” on DB-25 I/O are directly in-/outputs of AVR microcontroller with its 3.3 V output voltage, while J7 “LOAD” and J8 “LOAD” outputs on the back of the controller are controlled by “load_1” and “load_2” too (over IN3 and IN4) but you have +Vcc (with a high side current monitor with its output watched by the ATtiny on the board) over a mosfet and finally a 40 V zener diode. As the power supply enclosed in the Onefinity Controller case is a 36 V version of Meanwell LRS-350, these outputs are 36 V outputs.
On Buildbotics.com controller, these “LOAD” outputs are rated with 10 A:
Each of L1 and L2 are capable of supplying up to 10 amps. However the total power budget for the Buildbotics Controller is 15 amps, so L1 and L2 cannot both supply 10 amps at the same time.
See also Buildbotics Manual v1.0 > Power budget
But see Meanwell LRS-350 36 V version used in Onefinity CNC Controller for total power on this controller.
Also a difference is that the pins on DB-25 can be used the way I already cited above:
This has been discussed and shown frequently in this forum. You can find it easily:
The router and the dust collectors should be both switched on with M3/M4 commands so the ‘tool-enable’ pin is the correct output. As most users here use the Onefinity to mill wood and wood dust is not compatible with oiled mechanics like ball screws and is as well harmful for human respiratory system and cancerogenous, usually you want dust extraction to run always when milling motor is on.
Switching dust collector on with M7/M8 commands would require that your program and/or post processor diverts “workpiece mist coolant” / “workpiece flood coolant” commands from their intended use.
Also you don’t forcibly need “IoT” relays, if you can wire things you can simply buy a relay on a small board with screw terminals. They are easily available.
In any case look at the specifications of a relay if you buy, on the switched side they have to be rated for the voltage of your dust extractor and of your router respectively and to have enough current (Ampères) for your dust collector and this applies to router too. Use separate relays for dust collector and for router, even if you let them both be controlled by ‘tool-enable’. On the controlling side of relay, you got to know that generally you do not drive the relay with the power from the I/O pin sink/source current of AVR microcontroller (datasheet) pins directly which would be max. 25 mA. In order to drive relays, usually you have a power supply for this, e.g. one with 24 V which is a common voltage for this. The relays you can buy on small boards are switched by an optocoupler on the board so they are galvanically isolated from the switched circuit which is safe.