The concept behind this conversion is nothing new but most people are afraid of the electronics associated with it. conversion of an air retract is fairly straight forward. the piston is removed and a 4mm threaded screw driven by a 6v geared motor is used to drive the gear up and down. when the screw reaches the end of it's travel the motor stalls and draws a lot of current. Its this increase in current draw that trigers the Arduino microcontroller to shut the motor down.
The arduino UNO is the brains behind the system it's cheap and you can buy one online or at Maplins stores or electronic hobby stores. You'll also need the Arduino motor shield that fits on top of the uno. Thats it for the electronics. The motor you use will depend on the load and speed you wish to raise your gear by. i found a great source of cheap motors from this outfit www. uxcell.com . search for 6v 220rpm motors.
http://www.uxcell.com/search.php?cat...selectSearch=1The arduino is programmed from a computer and if you go on you tube you'll find hundreds of tutorials on the topic. Have a look at
Arduino - HomePageand search on you tube for Massimo banzi tutorials.
Arduino Video Tutorial 01: Get to know your Tools with Arduino CEO .... I'll post the code required for the retracts shortly once i've taken pic etc.