What you want is widely available under the name "Pan Tilt unit" Sometimes Pan Tilt Zoom or Pan Tilt Roll.
You are unlikely to want to zoom a paintball gun.
These mechanisms are often used for camera control but their use is much more widespread than this. The basic concept is simple - the actual execution ranges from trivial through vastly complex. Cost if you do it yourself can be almost nothing.
Doing it yourself can be conceptually easy.
Rotary motor driven platform. Could be stepper motor or any motor with suitable gearing and some form of position feedback. Stepper motor has advantage of position being inherent in commends given (subject to it not "slipping" when stepping.
Up and down tilt mechanism. Control with a hobby servo seems an easy and obvious start. Stepper or other motor control also possible.
Little else. Position sensing needed. Gun trigger. Radar or ultrasound tracking a bonus.
Not surprisingly, many makers of paintball gun robot systems call them "Paintball Sentrys".
The Sentry Project
Not the same as Jadiaz's Project Sentry Gun - and there will be others.
Added last but at the top, as *this seems to be very close to exactly what you want to start.
*The Sentry Project - how did we know they were going to call it that. This is the controller to turn a pan-tilt unit of your choice into an automatic targeting system - you hope.
I won't copy their interesting outline here. Have a look. They say
- If you have a turret (pan/tilt device) that uses hobby servos and has either a paintball gun, airsoft gun, water gun, nerf gun, laser, tennis ball launcher, pitching machine, video camera, or digital camera mounted on it, then the starter kit is what you would use to enable it to engage targets all by itself (as seen on the videos page).
One of many paintball sentry systems. Very real looking. Letsmakerobots paintball sentry system
- Robotic Paintball Gun Sentry. It's using a pair of RX-64 Dynamixels for the pan/tilt, with some major modifications to the default base platform. The entire base was designed in Autodesk Inventor and cut from 1/4" Black ABS on a lasercutter CNC. Onboard brains is an ArbotiX Robocontroller, which is programmed in the Arduino IDE. It uses a relay hooked up to a digital output to 'trip' the electronic firing control board that I yanked out of the paintball gun. Currently it's remote controlled using an ArbotiX Commander handheld controller and a pair of Xbee wireless radios, but a camera has been added and am working on a fully autonomous mode.
EMT paintball sentry turret dry firing test - you tube video
Access this video and you will see links to many other similar ones.
Paintball Brunei - Mobile paintball robot - tracked and wheeled. Looks lethal
Actually seems to be from here
Aha - being run as a kickstarter project and here
OTHER SYSTEMS TO GIVE IDEAS
Pan tilt video camera control using iPhone app over WifI - small and a camera - BUT the Wifi and iPhone control may give ideas.
Here is a very basic wikipedia introduction
Here are a whole range of "Robot Turrets" that do what you want but at a price that you certainly wont want to pay - but they show what is available.
Here is the result of a Google image search for pan tilt - this is immensely valuable as it shows you images of a very large number of implementations - some are clearly DIY - and you can access the relevant web pages as desired.
Here are a limited number of Pan/Tilt/Roll mechanisms and accessories that give an excellent idea of how real world systems are implemented.](http://www.servocity.com/html/pan_tilt_roll___accessories.html)
Yeeha! - Each of the above individual items has links to its own page - many with excellent details and discussion. Pricing is qyuite reasonable in some cases. Here is their SPT200 Pan & Tilt System prices at $US45.99 with versions from Futaba or Hitec. Price does not include the ervos and the 2lb capacity will probably be below what you want (maybe not wityh careful counterweighting) but it gives a superb idea of what can be done. Many pictures + discussion. They say:
- Our new Direct Drive Pan & Tilt System is perfect for cameras or sensors up to 2 lbs. One of the biggest problems with servos is they can not always handle heavy side loads even though they may have the power to rotate your attachment. As you can see from the pictures, our system incorporates 1/4” shafts supported by dual ball bearings and rigid 1/4” ABS plastic which makes it the most rigid and precise direct drive pan and tilt available. Three 1/4” holes in the top plate make it extremely easy to mount any camera or sensor. This plate can also be easily drilled to accept other attachments. The Direct Drive Pan & Tilt System can use any standard size Hitec servo. For cameras up to 1 lb, the HS-645MG or the HS-485HB servos work very well. For cameras up to 2 lbs, we suggest the HS-985MG or for the ultimate pan and tilt, the HS-7950TH. If you are needing more than 90° of movement in either the pan or tilt, you can order servos from us pre-modified for this on the Hitec servo pages. Unit comes unassembled with full instructions. Servos are not included and must be purchased seperately.
More good examples of real world systems