This is what I came up with:
It is a little bigger than what I would of hoped but maybe I will make a smaller desktop/ office version soon.
It uses the Arduino as the brains of the operation and do note I'm still quite new to Arduino.
It use 3 servos to control tension, angle and trigger.
Tension and angle are controlled but two potentiometers.
The trigger is controlled by a push of a button which also resets automatically!
There is a extra button for Manual Reset if needed, As well as the on and off button (blue)
all powered by Arduino and a custom shield to run the servo without killing the Arduino
Let me show you how I build it so you can build your own!
Step 1: Materials and tools
Grab some paper and draw what you want! This way you wont spend hours in the hardware store getting things you wont need.
My design is very basic, it uses a H shaped piece for the angle stopper and just a simple arm made out of a plank of wood that share the same pivot as the H piece.
Design yours how you want, even do a Google on some designs if you don't like mine.
I have listed some pictures to look at for ideas.
When you have your design and idea your going to need to get the stuff to build it out of, Now it doesn't have to be wood, I could be anything!
Try and keep it light to keep the work low on the servos.
I went down to my local hardware store and picked up a bunch of wood for around about $15 for this project.
Your also going to need basic tools, bolts and other junk depending on your own design.