you need 0,3mm drill bits for 0,25mm cable and 0,6mm drill bits for 0,5mm cable. and you need HSSG drill bits, all others break too quickly.i have used 0,5mm but if i would do it again i would use 0.25mm for the whole ship. this was my soldering plan for 34 cold white 5mm led's and 1 red led for...