I do not know how to solder the pins (that connect to the Arduino pins) from the wrong side so I just placed them on the top side of the PCB and pushed the tips through.
To safe some time I wrote on the PCB were the parts for the laser driver should go. Side note: for test runs without laser you can leave out the circuit for the laser for now.
I have also included an exported shopping list from my electronic merchant as it is sometimes a bit daunting looking up all the parts with different descriptions.
I did order the wrong relay from my electronic supplier so I ripped apart an old pc power supply I found in my electronic chest of wonderments. I am actually quite glad I keep alot of the “old stuff”. Most of the electronics are still working. I rather keep them instead of making the recycling depot happy. They sell it to Africa as “2nd-hand” which is not realy the truth.
Hence I have build this laser. Show people that “the old stuff” is no junk. In the right hands it is as precious as real money.
NOTE #2 (important):
When connecting the Arduino with installed board be sure to connect the external power supply FIRST.
I noticed that when connecting the Arduino to USB first with out power supply the motors start to scream. This does not sound healty. Remember the movie “Screamers” ?