here is an easy print box mod i have designed for use with a single 18650 battery,

i have listed below all parts that have been used to wire and connect it up to a fully functional "mechanical"  mod it functions like a mechanical in the power will go down as the battery dies, but when using the parts listed below, it has reverse polarity protection, low voltage protaction and will not fire any higher than 50a.

similarly the cutouts for the 510 and the button are also for the parts below, but for note the switch hole on right side is 12mm and the 510 is 10.5mm (space for an m10 thread)

switchfet v2.5 -
http://www.modmaker.co.uk/Switchfet-V2.5 (mosfet)

switch -
http://www.modmaker.co.uk/12mm-Stainless-Steel-Clicky-Switch-With-Flat-Flush-Actuator?search=12mm%20Stainless%20Steel%20Clicky%20Switch%20With%20Flat%20Flush%20Actuator

510 connector -
http://www.modmaker.co.uk/Fat-Daddy-Vapes-510-V3-Short-Body?search=Fat%20Daddy%20Vapes%20510%20V3%20Short%20Body

i used the contacts from one of these sleds -
http://www.modmaker.co.uk/Blossom-1048-Dual-18650-Battery-Holder?search=Blossom%201048%20Dual%2018650%20Battery%20Holder

the wiring diagram for the mosfet is included on the site linked,

the drip tip included is made to fit this blank (not needed but looks pretty :D) -
http://www.modmaker.co.uk/510-Drip-Tip-Blanks-10mm?search=510%20Drip%20Tip%20Blanks%20%2810mm%29

NOTE
dealing with electrics and batteries is dangerous, please use utmost caution when building this, and triple check every connection made to make sure there are no issues.

any issues are at the users discretion... you have been warned!

Enjoy! :D

When printing, nothing NEEDS support when printed in the orientation provided, but it is recomended as will give a better finish for the holes and i recommend rotating the box part 45 degrees so that it is stood upright and then printed with full supports, this will give the best overall finish when paired with the side cover.