See it in action here: https://youtu.be/PHySMmbABcs

Really liked XOTFC's design for using a 555 timer and a small trim potentiometer to move a servo. It's very simple to put together and cheap to make so I drew up a hand-held housing for it and incorporated a battery case to make it a useful SERVO TESTER for my tool kit.

It is designed for me, so I left it open for ease of use. Feel free to modify it to fit your needs better.

Fun, easy solder-less project that is useful too!

See the original schematic and a video of how to wire it here: http://www.xoftc.com/Circ555/Circ_555_servo_control

Note: Because of the built-in 9V battery I added an on/off switch and LED.

Note: I made a knob for the trim pot, though if you are going to be using this fairly often I would recommend switching this part for an actual surface mount piece. If you want to use the knob anyways, it is just glued in place with a bit of epoxy (crazy glue would probably work too.)

Note: Still looking a the wiring, I am sure it can be optimized and improved. Who knows, I may get bored and rewire it up all over again, that is why I left the hand-held open on a mini breadboard instead of soldering everything down :-)