Here is a short video of the factory showing the LED sorting/testing machine. It tests each LED and measures its exact light frequency. Any that fall outside set parameters are rejected. It then automatically organises them the correct way around and with exact spacing onto cardboard tapes ready for the insertion machine:
After the LEDs are ready they are fitted to the LED inserting machine. It takes each LED and puts it the correct way around in the correct hole. This machine is (again) assembling three colour (RGB) panels for outdoor signs - it inserts a row of red LEDs, then a row of green and finally a row of blue - then starts again for the next row:
All of these machines have to be setup for my product to be run and this is one of the reasons the factory can't do short runs - it simply isn't economically feasable: