Servo/Motor for barrier gate I am working on a small project that will need to check for proper UPC's then if validated, lift a barrier gate to move along cardboard boxes. The Arduino comes in with the gate lifting. I have this barrier gate working with a very small servo that came included with the Arduino Starter Kit, but this could not hold the weight that might be pushing up against it with a longer arm. Has anyone had any experience with something like this or could someone direct of a power supply/servo combo that would be up to the task? These boxes could weigh up to 20 pounds.

Thanks!
You may purchase a servo motor with greater torque.

You may find both DC as well as AC servo's. If you are using it in a real industrial scenario I would suggest you to use the AC, as you may not have to convert the ac power to DC and these motors will need real high current. So it would be better if it works on the main voltage. I did find PANASONICs ac servo as google search result.

If you have problems with integrating the greater torque motor to your current system let me know i can help you out.