Shop OBEX P1 Docs P2 Docs Learn Events
Beginner: Motorised Camera Pan and Tilt — Parallax Forums

Beginner: Motorised Camera Pan and Tilt

Dr_ZoomDr_Zoom Posts: 3
edited 2008-08-18 06:30 in BASIC Stamp
Hi,

I'm new at this, and need some help getting started on my project. I have done a lot of programming before, but nothing like this.

I would like to build the following:

A small unit that can pan and tilt my camcorder (350 grams).
It should fit on top of my tripod and fit in a 1.0" pipe. ( I know.. tiny)
I should be able to have wireless control (via remote control or wifi or Bluetooth ect)
It should be able to program it. ( Eksampel: if I press "1" on the remote control then turn left 5° at x speed and 3° up at y speed)
Run on batteries


How do I get started? Can I use the "BASIC Stamp 2 Module" as my core? What motor(s) should I choose?

Thank you for any and all help!

Comments

  • patterson7019patterson7019 Posts: 25
    edited 2008-08-13 17:42
    Can't help with wireless yet, but the stamp can do all of what you want. A couple servos like the Parallax (Futaba) Standard Servo. Not sure what the load capacity is on them, but if you need more, you might want to get the Parallax Servo Controller (Serial) which also lets you set the speed the servo should move. I use controller now, and really like it since I don't have to worry about the frequency I am updating the servos at.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    http://perfectaperture.com/robb
  • SRLMSRLM Posts: 5,045
    edited 2008-08-13 18:16
    Sounds like you are trying to make a cheap platform to make professional camera pan system. The size requirements will make everything difficult, but if you are willing to stretch it a bit the standard size servos would work fine. Your minimum dimensions would be about 2*4*2, not including the camera or powersource. However, this would be very cramped and a bigger system would be fine.

    If you do decide to go ultra small, take a look at the model helicopter industry. They have some small servos that are really powerful.

    As for wireless, parallax sells a pretty small wireless reciever module. Any wireless system that you choose will probably require that you have another BS2 to transmit to the stand.

    Mostly, I think this is a hardware project.
  • Dr_ZoomDr_Zoom Posts: 3
    edited 2008-08-13 18:30
    SRLM said...
    Sounds like you are trying to make a cheap platform to make professional camera pan system.
    Yes. I will use the system to make better adventure travel videos. yeah.gif
  • SRLMSRLM Posts: 5,045
    edited 2008-08-13 21:11
    Ah, good. It's very annoying watching homemade videos that go all over the place except on the subject. However, I should take a moment to mention that if size is a concern you'd do best to use something commercial. As much as you may hope, you're probably not as good at making a small product as a team of 100 engineers. That said: sounds like fun! A thought: make sure that you can charge/replace your batteries wherever you are. Nothing worse than dead batteries...
  • CannibalRoboticsCannibalRobotics Posts: 535
    edited 2008-08-13 21:40
    That's a really cool idea! Craming all of that into a 1" pipe is going to be a challenge. A servo with enough umph to move the camera will be a tight fit.
    What does your RF range have to be? I've used the Lynx tranceivers for similar projects but they are not good for more than about 50' unless you are willing to build them their own board with a bigger ground plane that anticipates the outer shape of your 'thing'. IR would probably be the cheapest and easiest to implement but it has some drawbacks in terms of daylight interference if you are using this outdoors.
  • SRLMSRLM Posts: 5,045
    edited 2008-08-13 22:36
    Check this page out:

    http://www.parallax.com/Store/Accessories/Communication/tabid/161/CategoryID/36/List/0/Level/a/ProductID/111/Default.aspx?SortField=ProductName,ProductName

    The range is more than good enough for your project, and the're relatively cheap too. Not to mention small...
  • patterson7019patterson7019 Posts: 25
    edited 2008-08-14 17:50
    I happened across a thread that pointed to http://www.servocity.com/html/pan_tilt_roll___accessories.html for pan & tilt systems. Looks like they have some good prices for servos too.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    http://perfectaperture.com/robb
  • SRLMSRLM Posts: 5,045
    edited 2008-08-15 05:49
    Looks like you can get the servo pan/tilt setup you need for about 45 dollars. Good find!

    http://www.servocity.com/html/spt200_pan___tilt_system.html

    It won't fit in your 1" tube, but I think that's a pipe dream anyway. (Alright, bad pun...) Anyway, You'll still need some sort of microcontroller system. Question: Does the tilt, pan system come with servos? I couldn't tell from their documentation... Almost hope not, since you'll probably want continuous rotation servos instead of standard servos.

    Anyway, they also have a joystick that you could use. Looks about travel size:

    http://www.servocity.com/html/2_servo_joystick.html

    Anyway, good site. It's going in the favorites.
  • Dr_ZoomDr_Zoom Posts: 3
    edited 2008-08-17 19:37
    Does anyone know how I calculate the torque i need on the servos?
  • FranklinFranklin Posts: 4,747
    edited 2008-08-17 21:18
    torque is usually measured in foot/pounds or inch/ounces in the US and something like neuton/meters in the UK. Inch/oz is the ability to hold 1 oz on an arm 1 inch long.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Stephen
  • SRLMSRLM Posts: 5,045
    edited 2008-08-18 06:30
    To find out how much torque you need (from a physics view), find the mass of the camera, and the center point. Measure the distance from the center point to the axis of rotation. Do the same for the platform, and anything else you stick on there. Then use the torque equation to figure it out. Engineers usually multiply this amout by 1.5 to have a safety margin. The torque equation:

    torque = rFsin(theta)

    Where:

    r = radius
    F = Force applied
    Theta = angle of applied force.

    The force applied is the gravitational pull by the camera, and the angle is how tilted this is. You'd do best to use the worst case scenario for this (1), but if you never expect your camera to go horizontal then you can choose your own value. Keep in mind that R is the radius distance to the center of mass of the camera, not the edge. The center of mass can be found·by dangling teh camera from a string in different orientations in each of the three dimensions.

    The equation for force applied due to gravity is

    F = mg

    where:

    m is mass
    g is gravitational acceleration (9.8 m/s2 or 32 f/s2)

    You'll have to run each component through the equations, then find the total torque reguired for an axis. Then simply choose the motor that gives you your requirements. Keep in mind that you must use the same units in all of your equations: metric or imperial. It's your choice, just don't confuse them. Finally, this is for one rotational axis. You'll want to do the same for the second if torque is an issue.

    Hope you made it through the physics review...
Sign In or Register to comment.