DC motor Pan-tilt & Camera Q

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

I'm designing a pan-tilt platform to be controlled by LabVIEW + joystick, via an Arduino (see my other thread for details). It needs to support a substantial amount of weight (20+Lbs) so I'm going with the DC motors over the servo motors for this reason (and the $$$). Anyone know of any good DIY's on pan-tilt thingies? I was thinking of using the joint (where the frame meets the forks) on a bicycle for the 'pan' bearing, by cutting off the forks and replacing them with a gear (parallel to the ground for pan), and then building a stand off where the bike frame would normally attach.

It would really help if someone had experience with this type of thing though.

Also, any advice on making it move smoothly? with soo much weight, theres going to be a lot of momentum (inertia?) to combat, not to mention the clunkyness of large DC motors themselves. The motors i have come with adjustable internal limits so i could set a max pan-tilt range in the motors, and not have to worry about maxing them out with the arduino.

It would be really great to work out 360 degrees of pan, but i cant quite figure how to get the power where it needs to go without twisting wires. surely theres power connectors for this type of application, like the brakes on bmx bikes?

Also, maybe someone knows something about CCD cameras? i'm looking for a CHEAP but decent black and white digital video cam, that either has motorized zoom or can have a zoom lens mounted on. On that note, anyone know of any good & cheap motorized zoom lenses?
I don't need any startling resolution but it would be nice to have a good frame rate.

Cheers

A

2

Ok there was a lot there, I can only answer to a part of your questions.

20lbs is pretty tricky. At least look at Servo City for pan and tilt systems using hobby servos. These things can handle about 10lbs tilting although the pan systems can do a whole lot more with the right servo attached. Maybe it can help you design something for your needs. Take a look here: http://www.servocity.com/html/pan___tilt_systems.html

The other problem with most motors is they will want to overshoot their position. Precision wont happen easily.

The other thing is that you need to look at what are called slip rings. I dont have a good source but know you can get some with numerous connections. They are not cheap but are the only way to solve your wire problem.

Cheers,
Brian