I'm looking to make a gear head for my tripod. Any suggestions? Anyone ever try this? I'm have a serious amount of machining background. I'm not intimidated by the project, just the design details that I might miss.

What do you think Charles? Am I nuts? I just want more control over my pan and tilt than using a fluid head.

David

By "gear head" what do you really have in mind? A gear mechanism to pan and tilt on the tripod?

Yep, Same as the Panavision Pan/tilt heads.

I built motion control pan/tilt heads for Dreamquest Images many years ago. Those were with stepper motors and Berg belts.

In all actuallity, I'd like to prototype a head that could be manufactured for a reasonable cost for use with DV cameras.

Hey, it sounds like you're the guy that can do it. Charge-on! If you can keep it under $500 for a design load range of 4-12lbs you'll have many orders.

BTW, you probably already know this, but Varizoom already makes a motion control head (the VZ-MC100 (http://www.varizoom.com/pages/mc100.htm)). It's darned expensive but reportedly well designed.

I don't know why you want to build a gear head, but if your purpose is to imitate professional camera operation, you will find more and more cameras used in film operated with fluid heads. The improvement in design of the fluid heads combined with the smaller cameras make for a very popular combination. In fact, famed Director of Photography, Vitorrio Starraro insists that his operator use a Vinten fluid head on all his projects. His claim is that the fluid head makes the camera more "organic" with the operator.

But have fun with your project.

Well. European DP's in particular have a fondness for fluid heads, and I have often heard the "organic" term bandied around. After growing up with fluid heads then learning the "wheels" i.e. gear head about nine years ago, I feel comfortable saying at this point that if properly operated, it should be impossible to tell which head is in use from looking at the results. I prefer a gear head for most kinds of shooting, switching to the fluid head for whip pans, extreme tilts, self-operated zooms (yup, in the film world it is often the camera assistant who works the zoom, I know it seems alien to most of you!) and fast, unpredictable motion. Dolly shots in particular are where the gear head shines, as starts and stops can often cause bumps in the photography with a fluid head (your body inertia results in involuntary tilts). Also it is easier to dial in slow continuous movements. I know many operators who have different preferences, but rarely do I see those who are completely comfortable and competent with the wheels opt exclusively to use a fluid head instead, if you see what I am getting at.

As far as building your own, David, I am fascinated to see what you come up with. There's quite a bit of elegant mechanics in there, for it to work well there needs to be an absolute minimum of backlash plus a nice smooth gear shift mechanism. Reverse engineering an Arrihead would be a good start! I would recommend attempting to build it using a L bracket support design rather than the classic arcing design, in other words a nodal tilt mechanism which means greater tilt range than the 60 degrees usually found in a classic gear head.

Ken, I was startled to hear that Varizoom offered a motion control head, then I looked at the page. I would designate that as a "remote head", whereas a motion control head allows for programmable and repeatable moves, which would be a fantastic bargain for $3000, and I'd write a check today if it were the case!

Aha. So for nomenclatural clarity's sake would it be most accurate to define a Motion Control Head as a device that provides the operator the with ability to programmatically set and control the camera's movements in 3 independent axes wih respect to time? For example, acceleration curves could be set and locked-in for the camera's pan, tilt and roll.

Versus a Remote Head which permits control, but not programmatic control, of the camera's motion in 1-3 axes.

Is this pretty close to a reasonable working distinction?

Thanks Ken and Charles. Charles, I hadn't even considered an L-Bracket with nodal axis. That sounds like a couple of anti-backlash worm gears and a few handles.

I also have a feeling that the gear head needs to have some mass to it so that while turning the handles, you don't cause the tripod to move.

Most of the heads I have seen have been mounted on a dolly or maybe a high hat mounted on the ground. I don't recall seeing a head mounted on sticks very often. The construction of the arm on a dolly is incredibly robust. That helps isolate vibration as well.

Hmmmmmmm.....................................

David

If you get one of these built i would buy one for sure if they are very cheap. Or i would promote it around my town and get the shops onto you in exchange for a unit.


Zac

Kermie,
You can be sure that what David's thinking about ain't gonna be cheap! <g>

Ken,

Heh that is why i suggested another way, i know a few camera stores here that would prob buy into them and get a few, they got some skycranes after i put them onto them.

zac

Ken,

Motion Control is not only used to control camera(s) but
also models, objects, cranes and other things. One of the
more interesting things is that it can repeat a motion exactly
same everytime to photorgraph different layers or do other
effects.

But basically your definition is correct!

<<<-- Originally posted by dmesloh@gimixfx.com :
Most of the heads I have seen have been mounted on a dolly or maybe a high hat mounted on the ground. I don't recall seeing a head mounted on sticks very often. The construction of the arm on a dolly is incredibly robust. That helps isolate vibration as well.>>>

David:

I will always work off the dolly if I can help it, mostly because I HATE levelling a Mitchell (flat base) head off sticks. Having to screw around with raising one leg, lowering the others etc. is just a royal pain compared to the quick height adjustments on the dolly. Plus having a seat is a nice way to get through those long days!

Nevertheless, I will use sticks when the location requires it for one reason or another. A solid set (Ronford makes the industry standard) is strong enough to handle the torque created by most operating situations. A geared head, incidentally, transmits less torque to the support apparatus than a fluid head.

Myself being a lazy machinist (among other things), I'd look to build something a lot less expensive than a 'real' metal gear-head.

Maybe a timing belt can be substituted for the gears. A whole lot cheaper and lighter. If mass is required, it can be added where it will do the most good, not distributed over the mechanism.

Perhaps one can engineer an add-on mechanism to some of those terrible but terribly strong Bogen heads with the removable sliding plate. Lots of room for mounting sectors.

That would also make it relatively easy to add a stepper or servo drive if one needed to remote the head.