Building a turntable for actors
January 20, 2010 9:55 AM   Subscribe

I plan to put 3 actors on a 6' wooden turntable (which I will build myself) for a video shoot. Have you done or seen something like this before? Is my turntable design workable? Is there a better/simpler/safer way to do it? Details follow.

I'm planning a music video shoot that involves sequences of stills that create the effect of the camera "orbiting" around the actors. This will be shot against a greenscreen, with background imagery being added in post-production.

At first I was planning to keep my actors stationary, and move the camera around them. But I was concerned that doing so many different camera setups would create choppy, inconsistent results. This is ultra-low-budget, and will be shot in a very confined space, so a camera dolly and curved track is not really an option.

The solution I'm looking at now is putting the actors on a turntable, and simply rotating it slightly for each shot. (Again, I'm shooting sequences of stills, not continuous video.) I think this would ultimately be simpler in terms of camera setups, lighting, greenscreening, etc.

Here are my plans:

- The table will be 6' across. I figure I can build it from a couple layers of wood planks, with the top layer attached at right angles to the bottom one. Alternately, I might have the 2 layers of planks parallel to each other, but with a layer of spaced 1x2s in between, at right angles to the planks. I'm not sure which of those 2 options would be better. The table will need to be sturdy enough to hold up to 3 adult actors, but some scenes only involve 1 or 2 people.

- I'll cut a hole thru the center for a hub or shaft, which will be firmly attached to the floor, and will project up thru the turntable.

- I envision resting the turntable on a dozen or so golf balls, which will function as bearings. Each ball will be confined within a "housing" attached to the bottom of the turntable, which will be a small piece of 3/4" thick board with a hole cut in it, just large enough for the ball to rotate freely.

- I may build some kind of bracketing piece(s) along the rim, attached to the floor, that will be designed to ensure that the turntable stays level. Also, I will need some kind of simple, quick locking mechanism, to keep the table still and secure for each shot.

So, does this sound realistic and reasonably safe? Am I overlooking anything important? All suggestions welcome.
posted by Artifice_Eternity to Media & Arts (20 answers total)
Why golf balls when you could use actual wheels or casters? The golf balls are just going to get wedged in whatever homemade thingie houses them and not go anywhere. Also six feet in diameter with a shaft in the middle is a very small space. Mock it up with a chalk circle on the ground and see if that's going to be big enough.
posted by oneirodynia at 10:02 AM on January 20, 2010

I agree with oneirodynia---casters are not very expensive. If you just have a lot of golf balls that you need to use, you may as well make the bottom flat and rest it on free-rolling golf balls. Put a rim around the outside so the balls can't escape and rotate the table carefully---but it's stills so there's no hurry, right?
posted by tss at 10:10 AM on January 20, 2010

Use low friction furniture pads resting on carpet to replace golf balls or wheels? Locking can be a pin placed through a hole on the disk.

But with people on it how heavy is this and how does it move smoothly?
posted by Freedomboy at 10:12 AM on January 20, 2010

When you say "planks", you should be thinking plywood.

Take four 4x8 sheets of plywood. Lay two down side by side. Apply a liberal amount of construction adhesive (PL-300 or the like). Lay the other two sheets on top, in the opposite direction. Drive in 1 1/2" wood screws every 12" across the sheet.

Once the glue sets, this will become a very solid platform for your purposes.

Use a skilsaw to cut this down to a 6' x 6' square. Depending on how perfectly round it needs to be, you could use a jigsaw to cut the corners off (use the old pencil on a string trick to get your shape). If it's not crucial, just lop the corners off and end up with a large octagon.

oneirodynia is right - you want casters, not golf balls - the golf balls will bind and jam up on you. Casters will let you rotate very smoothly. Bolt them to the bottom of your plywood disk. You'll need a caster every 12" or so around the circumference of your platform (about 6-10" in from the edge) - in fact, a smaller ring of casters 18" or so from the center would likely help keep the platform from sagging.

I'd use some sort of pillow block bearing with a steel shaft as a rotation point.

You'll need some sort of base for the center to attach to (unless you can affix it directly to your floor). A few sheets of plywood will do the trick. You might have to use steel connector plates or something similar in order to connect the two pieces together.

As far as a brake to hold it in place, some sort of wheel chock on one of the casters should work - alternately you could get casters with brakes built in.
posted by davey_darling at 10:16 AM on January 20, 2010 [1 favorite]

The theater way I learned to do this is a platform of 1x covered in ¾” ply with a series of fixed castors, with a hole cut in the middle for a pivot point. Here is a far too complicated explanation. A simple wagon brake should work if you don’t need to lock it down too firmly. This is basically a lever with a little rubber cap on it that you should be able to find at a home depot. Here’s a McMaster Carr page for them.
posted by edbles at 10:26 AM on January 20, 2010

No personal experience but I would do it with the actors stationary and the camera mounted on a counter-weighted see-saw device/arm that has it's center above the actors and I'd put the green screen on wheels.

What I have done is build Dobsonian telescope mounts that have sheets of plywood with cheap formica glued to the bottom and then everything rides on an array of teflon pads. If you make your central pivot point a tiny bit higher than the perimeter it will rotate more freely.

I'd really avoid putting them on a turntable, though.
posted by bonobothegreat at 10:34 AM on January 20, 2010

Response by poster: Thanks for all your suggestions.

I'm pricing casters now. Question for those with experience: Does an individual caster need to be rated to bear the entire weight of the turntable and actors, or just the total weight divided by the number of casters used?
posted by Artifice_Eternity at 10:34 AM on January 20, 2010

Response by poster: A few thoughts in response to some of the comments above:

- Using furniture pads or something similar had occurred to me. I'm just concerned that smoothly sliding the turntable with the actors on it, maintaining their positions between shots (which is necessary for the video concept) would be difficult.

- Building the turntable from large plywood sheets had also occurred to me. The problem with that is that I live in NYC, don't have a car, and will be shooting this in my apartment. Transporting and working with 4' x 8' sheets of plywood would be a huge pain and an added expense. Boards are much easier.

- I think rotating the camera and greenscreen would require a much more complex setup, and a lot more space than I have. Also, it seems like consistent lighting would be a problem.

But thanks again for all suggestions.
posted by Artifice_Eternity at 10:43 AM on January 20, 2010

Since other folks here have the construction angle covered, let me point out something from the video aspect. If you only rotate the actors and the camera, green screen, and lights are all stationary, you may not get a feeling of camera movement. The lights will be in the same place relative to the camera for each shot. I suspect it'll look like the actors are rotating, not the camera.

You could solve this by repositioning the lights every time you rotate the actors, trying the keep the lights' positions the same relative to the actors. You may run into trouble with this if your space is limited.

I assume you're going to composite onto a moving background, which will help. You might be able to get away without moving the lights if you light everything pretty evenly. But if you're going for strong side lighting, it'll be apparent if the lights don't move with the actors.
posted by echo target at 11:04 AM on January 20, 2010

Post a link to the final shot[s] for us OK?
posted by Freedomboy at 11:21 AM on January 20, 2010

Look into the various homemade and commercial turntables for pivoting motorcycles in small garages. (You can even make heavy duty ones for cars.)
posted by Forktine at 11:34 AM on January 20, 2010

Lazy Susan.

I use one mounted on a box to pivot 800lb+ pianos in tight spots. Inexpensive and durable.

The example is from McMaster Carr, but a decent hardware store will carry them.
posted by pianomover at 11:50 AM on January 20, 2010

Response by poster: echo target: Point taken. I am planning to use fairly non-directional lighting -- for the reasons that you cite, and to keep the lighting plan simple (since I'll need to light both the actors and the greenscreen, without either set of lights interfering with each other).

I might use a little directional light -- maybe just one key source, which would be easy to move around with the turntable, as you suggest.

As for the backgrounds, they are mostly going to be pretty abstract. I actually want to create the sense that the actors are hovering in a kind of void, with flat, symbolic imagery behind them, rather than merged into very distinct locations.

Freedomboy: I will definitely come back to this thread and post a link to the results!

Forktine: The commercial ones look way too expensive for me, but the link to the guy who used furniture slides to rotate his motorcycle is interesting. I'm wondering if using a whole lot of felt-bottomed furniture slides might in fact work OK.
posted by Artifice_Eternity at 12:09 PM on January 20, 2010

Response by poster: pianomover: Thanks for that link. Those turntables have got me thinking. Perhaps I could use one of those under the center of my platform, with 2 or 3 rings of furniture glides around it.
posted by Artifice_Eternity at 1:27 PM on January 20, 2010

how heavy is your camera? can u attach to the ceiling, or overhead? Maybe swing an arm in a circle? Could u greenscreen out one of those floor-to-ceiling poles? Surplus dental equipment? or film in dentists office? Steal a tether ball pole from the local school? Shoot in a gym and attach to the backboard?
posted by at at 10:55 AM on January 22, 2010

Wait a minute! Contrary to my earlier answer, I did do something like this once where I put my wife on a turntable to get some photo reference for a sculpture. I got sheets of cheap formica at the building supply store and layed them on the floor with the finished sides facing each other. They slid with very little friction (but you may want to compare samples in the store -I think pebbly finishes are best). If you bought 4 sheets (4'x8') they are super light and you just need to roll them up to carry them. Then you can tape them together on the backsides. If it's important, you could drill a hole for a pivot point in the middle. If your actors are standing in a line, you'd only need 3 sheets.
posted by bonobothegreat at 11:12 AM on January 22, 2010

Also, the closer all your actors are standing to the middle point of whatever turntable you decide upon, the easier (by a factor of 10) it'll be to turn.
posted by bonobothegreat at 11:29 AM on January 22, 2010

Response by poster: UPDATE: After various delays, I'm shooting my video next weekend. I refined my turntable design, and bought all the supplies. Here's what I settled on:

- 2 layers of 3/4" pine boards, at right angles to each other, cut to form a circle 5'8" across.

- 2 concentric rings of casters affixed to the bottom (an outer ring of 12 plus an inner ring of 4). Some of the outer casters have brakes on them, so I can lock the turntable position as desired. I'll also use some kind of chocks or shims to further immobilize the wheels.

- A 1' diameter round "lazy susan" turntable from McMaster-Carr*, sandwiched between layers of plywood, at the center of the underside. The bottom plywood layer will be attached to the floor via duct tape. This assembly will be the pivot around which the whole thing rotates.

I haven't fully assembled it yet. I'll post another update after I do.

*Thanks again to pianomover for this suggestion!
posted by Artifice_Eternity at 10:06 AM on May 21, 2010

Response by poster: UPDATE: I assembled the turntable on Thursday, and shot my video today. It worked exactly as planned!

Here's a photo showing what the underside looks like:

And here it is in use:

At various points I had 2 actors on it. It remained steady and solid the whole time. It didn't turn completely frictionlessly, but the moderate resistance was good -- it meant that we didn't have to worry about locking it in place between rotations, because it basically wouldn't move on its own.
posted by Artifice_Eternity at 10:28 PM on May 29, 2010

Nice job.
posted by bonobothegreat at 10:50 AM on May 31, 2010

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