Update: what about a linear actuator? Which I know nothing about!
I want a 3 foot arm running parallel to the ground to move 90 degrees back and forth, like a windshield wiper - but not quite. One press of a button moves the arm 90 degrees - then the arm stops and stays rigidly in place. Another press of the button moves the arm back where it stops. Speed of this movement should be slow, say 2-3 RPMs. The load at the end of the 3 foot arm is 5-10#. I know nothing about math, physics, or motors or coding. I am looking for the simplest option, please.
Which motor would do this? AC? DC? How much torque would I need? Battery run or plug in? Gear box - don't really know what that is - would the motor mount at the fulcrum? Guess I would need a counterweight too - or do I make the fulcrum a hinge and attach a rod say in the middle of the arm like the mechanism of an automatic door opener. Trying to keep this under 50 bucks. Also fire safety is a big deal.
Is there a switch that will reverse the motor? Do I need a servo and some computer programming or can this be done more simply? Simple is preferred. I really don't want programming.
Thank you very much.