Building a motorized slider / pan & tilt head setup for <$1000 ?

Sangye

Sangye

Member
I have about $1000 to spend on some motion control gear for my GH2 rig, and I could really use some help figuring out what parts I'll need. At the very least I want a motorized slider with a motorized pan & tilt head. I already have a 5' Igus DryLin-W slider + carriage, so for the slider component I only need a mechanism to motorize it with. My rig weighs about 20lbs, so I think I'll need high torque motors. I plan to use this system both for timelapses and for live motion, so I may need to either buy two motors, or a gearbox for dramatically varied speeds (from sliding 1" every ~5 minutes, up to about 6" per second).

As for the pan & tilt head, again it needs to support up to 20lbs. It obviously needs to be capable of smooth movement, preferably again on vastly different time scales (for subtle pan/tilt movement during extended timelapses as well as live action movements).

If it's possible within the stated budget, I'm also interested in making this setup programmable. I'm not sure if anything like this exists, but it'd be really cool if I could both control it on the fly and program it from an iPhone.

If this is possible with extra $$$ to spare, I've also been thinking it'd be cool to convert the slider into a crane. With another very high torque motorized pan & tilt head supporting the slider on one end (with counterweights somehow fastened beyond that end), I'd think that crane movements could be motorized as well. This might require too big motors though.

I know I'm kind of throwing a lot of ideas out there hoping one of you will be able to put them together and understand and be able to relate back what I need. Thanks in advance.
 
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Hi,
for the forward movement You would need:
a high torque motor plus gears for a gear belt - get three different sizes, so you can keep the middle sized gear always mounted on one side, whereas you can exhange the small and big one (on the other side) for faster and slower movements, youll have to calculate that, depending on rpm of the motor - if that speed difference couldn't be achieved in this way, get you an intervalometer, you would get a DIY kit for this at about 50$, 12V input, and you can control the time between the movement and the duration of the movement by adjusting 2 rotating buttons. BUT: it will be very hard to achieve that big speed differences with just one motor, one gear gives you more torque, the "high speed gear" will steal it... and you'll need torque to move a pan an tilt head plus camera ;)

Pan and tilt head: do you have some sketch or a concept how the support for your camera should look like?
 
I would call up RobotShop, they sell 2 pan/tilt systems. One is $350 but only supports 6lbs, the other is $1499 and supports up to 40lbs. You could ask them if it is simply the servos which limits the 6lbs one to 6lbs, which I am sure it is, and if so, ask if you can buy the everything but the servos and get 2 different servos so it could handle 20lbs.

http://www.robotshop.com/aluminum-pt785-pan-tilt-system-2.html
 
I've decided to do this in two phases, holding off on the pan/tilt system for now. All I need at the moment is the belt and motor system, and whatever support brackets may be needed. I've also decided to remove my camera from its rig whenever I use the slider, so weight shouldn't be an issue. This'll also let me mount the camera to the slider carriage with an articulating arm, for more creative angles.

I've seen DIY motorized sliders where the motor was mounted to the camera carriage and pulled along a single length of belt, and ones where the motor was fastened at one end of the slider and rotated a loop of belt to move the unit. Any thoughts on the advantages of both? Where can I get lengths of belt that can be matched with a gear that's driven by the servo?
 
Thanks guys. Assuming I decide to attach the servo to the rail rather than to the sliding carriage, how would I link the sliding carriage to the belt? Is there a sort of quick-release clamp that could be fastened to the sliding carriage and be used to cinch down the belt when it's go time? I suppose I could permanently attach the carriage to the belt (superglue, bolts, etc), but I'd prefer to keep it as modular as possible.
 
Sangye said:
Thanks sinapps, that's exactly what I was looking for. Did you build this yourself? (I see the URL in your signature). If so, do you have any additional photos that might make it more clear how you fastened the servo to the rail?
Click to expand...

Sorry - I sold the slider some time ago. That page should have a downloadable PDF with the design of the holder (for laser cutting). Would recommend going with a servo that has more torque than the one I have listed on that page.
 
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