emceepaul:
I am making a very similar circuit. Attaching 3 LEDs in parallel and uses 9 columns of these to make a 3x3x3 cube. Problem is I cannot attach individual resistors to each LED. Hence, is there a solution whereby I can use 1 resistor for every 3 LEDs in parallel, use a transistor to supply approx 60mA of current?
You might be able to get around this,
I use LED's a lot for de-bugging so I made it easier by cutting off the anode really close to the LED and carefully soldering a 1k resistor to the anode stump. ( trim one side of the resistor so you have just enough wire to solder. )
You could use this same method in your cube.