Counter Strike

Before we get started: The writer of this document and all related stuff is not in any possible way responsible with what you do with this information.

With that out of the way, why would you want your personal sentry for anyway.

Well I want to:

1. Make an automated tennis robot

2. Keep something of my porch/lawn/dock/deck/driveway/etc

3. Have a Security/anti robbery system

4. Just have it for plain old neighborhood mayhem

5. Just scaring some friends

6. Make it recognize the shape of a weapon/pistol and use it for store-security in combo with a taser.

7. Build a better mousetrap

8. automatic skeet shooting competition

9. Give rise to my inner power-hungry villain on a quest for world domination

Ok well if that is what you want let’s start making your very own fully automated sentry projectile dispenser. You might want to read all of this before running of to the shed and starting slapping parts together.

First you need to make a choice of what you want to use the sentry for. This because the more weight, size and/or recoil the mounted dispenser has the stronger the rig and actuators have to be in order to be able to cope with the stresses involved in the dispensing of you chosen projectile.

Now that you have decided what you want to use it for you need to make a list of deliverables. In this the most important factors are considerations of range and accuracy.

Range is largely dependent on the quality of your camera and the range of the dispenser.

With regard to the camera more pixels is better for larger distances and accuracy but worse in terms of computing power and reaction times. In general, for reasonable distances of 10 to 30 meters a webcam with autofocus is a good investment. Obviously for the same distances you could also use a usb enabled camcorder or similar, night vision, infra red or thermal infra red is also a nice idea.

With regard to the dispenser one has to take into account that over a certain amount of distance the projectile is influenced by wind gravity and other factors such as temperature, air pressure and humidity. The further the distance a projectile has to travel the more influenced it will be. Therefore it is desirable to have a dispenser that has enough force to travel the desired distance in as little time as possible. Check your dispenser beforehand in order to see the general deviations trajectories might have and if this fits with the desired result as well as the camera you are planning to use.

Additionally you have to take into account the weight, size and recoil of the dispenser as reaction times, in terms of movement, are dependent upon these, i.e. use stronger bigger servos.

What you’re going to need to build your own sentry dispenser for tictacs, teddybears, bb’s, water, etc!