Introduction: Easy PCB Drill Press Run by a 12V Power Source

HI,guys,my idea is greatly inspired by '$30 High-Speed PCB Drill Press by lancandy' and "Easy Drill Press by LostRite",thanks for their generocity.sorry for my English,i'm from China mainland,i love instructables community and i've long been thinking to share something made myself.i happen to have a 12V rotor lay off which is ripped off from a portable grinder,it's perfect in spinning small  subtle drill bits.

The parts list:
Square Steel Tubing Shelf-custom-made from a local shop,=$12.00
Grinder Drill -  $7.00- THK Linear Slide Rail - $10.00
Linear Slide- $10.00-ordered from a local factory
MISC. Springs,Screws - from local hardware Shop

a 3 pin switch and a female head of a 12V line.$1.00  Note:the line has 2 thread,one connect to one rotor pin,another thread connect to switch pin,another pin from the switch connect to rotor another pin,the misconnect the pin on the rotor only result in rotor spinning the counterclockwise way.