Make TRS Drawbot Rail and Arm for 9g Micro Servo Tower Pro

This is used as Rail and Arm for the TRS Drawbot.
Tower Pro 9g Micro Servos (cheap China Stuff) should fit.
http://makezine.com/projects/trs-drawbot/

Distance between Servo center: 4,0" = 10,16 cm

Servocontra Part by dpruim.