The K40 machines differs a lot in what parts and function is has added, some has extra lights, laser dots and different parts already fitted, others are bare lasers.
These machines are already on the edge of what the power supply can handle, adding more load to it may create problems.
To solve this, we suggest that everything you add to the machine is connected trough a own power supply or smaller wall plug with correct voltage.
Doing this you can rule out all problems occurring in the machine to your added peripherals and make sure whatever it is, it isn´t because of your added parts.
I added a 24v 10A 3d printer power block and an LED 12v 5A block
24V runs the Board and Radial fan for Air Assist
12V runs a Waterpump and 2 120mm radiator fans for watercooling that runs into a 20L tank.
The 12V is wired with a separate cable and plug, 24v is wired to the Machine 240v input plug.
I bought a cheap 3-socket extension power cord as “distribution block”, cut off the plug and screwed the cables into the clamps of the on/off-switch.
I also had good use for the plug: I attached it with wire connectors to a 24V PSU (built and marketed for powering LEDs, hence came with bare cable ends instead of plug), which now powers a couple of fans. So basically, I plugged the plug of the extension cord into one of its 3 sockets.
The second socket powers the 5V PSU of an USB-hub, which in turn routes a USB type-B extension cord to the controller board and a webcam mounted in the lid.
Third internal power socket is still free. I’ll be careful not to run a crazy amount of amps through the original power cord, so no vacuum cleaner to be attached here. (No joke, I use a liquid sucking vacuum cleaner as a makeshift wet scrubber. So I had a short consideration of switching it on/off with the main power switch. I decided against.)
Can you recommend any power supplies as might be found on Amazon which I could use for LED case lights and laser indicator/guide attached to “air assist”? Any suggested wiring diagrams?
Pretty much any 12V supply will work. For LED´s only a 1 to 2A wall plug is enough. Install it inside your machine with a small “distribution block” where you can attach all your 12V stuff.