Thank you Robert. I think I might start with the A40640 and if I have enough project and demand might scale up to something else! 
Thank you for the input Sir! 
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I’m preparing to install an a40640 on my lr3. Could you share details of your solution to the cable charring problem. In addition, could you share your source for replacement 4 pin cables?
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I did not need to replace the 4-pin cable, but you will. When I purchased my laser module, it came with a longer 4-pin cable. By mounting the control board directly over my CNC, I was able to reach all areas of my CNC bed. I later purchased a second A40640 for a smaller machine. It came with a much shorter 4-pin cable. Regardless, no matter what comes with your module, you will need to extend the cable for your LR. My suggestion would be to purchase some 18 gauge, 4-pin wire, remove most of the wire from the provided 4-pin connector, and solder/graft that cable to the remaining wire (i.e. reuse the connectors). The connectors clip in, so I’m not sure the exact name. Dupont connectors will fit the pins/spacing, but then you would need a dap of low-temp hot glue to make sure they stayed in place.
As for my upgraded rewiring:
In this diagram, the 4-pin connects to the socket pointed by the red and black arrow. My solution was to rewire the two power wires to use the two studs outlined in pink using crimp fork spade connectors.
This laser control board is optional. On my small laser engraver, I don’t use this board at all. You really only need three connections to the module, 1) Power, 2) Ground, and 3) a PWM wire between the CNC control board and the laser. The 4th pin is used to communicate temperature, which I don’t use. Note if you wire your laser directly and are using a separate power supply for the laser, you must share a ground between that power supply and your CNC control board.
P.S. Not for this project, but for other, similar projects, I just purchase 4-pin wire off Amazon.
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Thanks Robert. I’ve completed my wiring per your instructions and it is working well.
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