View Full Version : Planning First Build

09-22-2015, 06:24 AM
Hello all, I'm building my first saber. I want to start simple but with plenty of room for upgrades. I've attached a photo of a wiring guide and parts, I would appreciate any advice on my plan.

Thank you for any and all comments!


Silver Serpent
09-22-2015, 06:31 AM
A single li-ion cell will not power a BuckPuck properly. You need a minimum of 5v to run them. You could either use a 2-cell pack (7.4v) or swap your BuckPuck out for a resistor.

Personally, I would use a resistor and the single li-ion. That way, it would be easier to add in a Nano Biscotte at a later date.

09-22-2015, 06:57 AM
Given the option I would rather have the single cell 18650, have plenty of them already. What resistor would you recommend?

Silver Serpent
09-22-2015, 07:05 AM
Give a man a fish, or teach a man to fish... :)

FJK has written a lovely tutorial that will teach you how to calculate your own resistor. http://forums.thecustomsabershop.com/showthread.php?17109-Tutorial-FJK-s-quot-Down-and-Dirty-quot-guide-to-Ohm-s-Law

The math isn't that hard. You'll find the forward voltage value for your LED on the store page. There's also a resistor calculator in my signature, but it tends to round up values unnecessarily. It's good for double-checking your math to see if you're in the right ballpark.

09-22-2015, 07:09 AM
I found the calculator. Correct me if I'm wrong. According to my plan,
Source Voltage=3.7v
Diode Forward Voltage=2.57v
Diode Forward Current (mA)=1000mA

The calculator output, 1.2 Watt capable or greater 1.2 ohm resistor.

Will this resistor work?

Silver Serpent
09-22-2015, 07:14 AM
That will work fine. You can always use a higher wattage resistor than what is recommended, it won't affect the brightness of the LED. Don't go overboard unless you need to, since the 5-10W resistors are BIG and eat up precious hilt space.

09-22-2015, 07:22 AM
I did the math provided by FJK (the calculation was easy, thanks)

I got 1.13ohm and 1.13w.

So going to a higher resistor won't affect the brightness, does it affect battery life?

Silver Serpent
09-22-2015, 07:35 AM
Higher wattage won't affect brightness or battery life. It just affects how much current can go through it at once before the magic smoke comes out. So long as you meet the calculated minimum, you're safe.

Ohms will affect brightness and battery life. If you go lower, you overdrive the LED. The LED will run brighter and hotter, and you run the risk of blowing it out. If you go higher, the LED will be dimmer. We generally recommend the value closest to the calculated value, rounding up is preferred over rounding down.