chocochunk

In January I began work on a specialty camera rig that could be used for a shoot of a corporate building with a range of sitelines. After going through a few designs on paper, I figured out that a tethered floating rig would provide me with a range of moving shots. And as long as I had a wide shot, I could correct otherwise unusable footage with the advanced motion stabilization in Boris Red 4. If I engineered it well it would allow me to float through doorways and still have range to have controlled floats up to 25′, as long as the heater fans didn’t kick on. I wanted to show the flow of the space, and given that I recently had purchased a sony dcr-pc55 (mini DV) I was set on applying it where ever its 12 ounces would fit. The constraint of this project? $300 budget. Creativity required.

The track was the first puzzle to figure out with the project. Given the budget I needed to work with, my material choices quickly dissolved since I planned on several 75′ shoots so that I would have enough captured to speed up the video.

The solution was to CNC cut 1″ mdf (medium density fiberboard) to my shapes which were laid out on paper then drawn into autocad. Then sandwich two pieces together with a finish nailer. The straight pieces would be 2″ tube mild steel. The 90 degree turn you see has about a 6′ radius.

Next up the “train” engine of the device. I needed lots of weight, and smooth rubber wheels that were less than 2″ in diameter. I had access to lots of mild steel scrap, so that met the weight quotient. I stopped by daddys Skate shop on sandy and picked up some skateboard wheels with ball bearings for about $60. So far the most expensive part.

After some trial runs I realized that I needed all 12 of the wheels I purchased. Between the side bumpers and top wheels it would take all of them to stay on the track. It took three prototypes and a few configurations to come up with this design. The side wheels need just the right gap to go through the turns without too much drag.

Next is the locomotion. In engineering school I was defeated in a cable weight competition by a group that used a high-torque drill to carry a dollars more worth of coins up a wire. Being one to learn from a loss, I finally had the opportunity to put this defeat behind me and adopt their innovation.

I stopped by Chas Day on 11th avenue, and they gave me a box full of power drills for free all of unknown condition. Also they had a grinder attachment that would fit the drill for $.69, a great budget friendly stop! I was able to piece together enough parts to get one that worked well enough, and after melting the grip off, I hose clamped it to a bracket made of 1×1/4″ mild steel.

Next on the list, I calculated out my ratios for a few choice shots, and drew up some diagrams for an in house machinist for the cable reel. After picking up a $25 piece of rolled aluminum in clackamas (3″dia x 12″) I handed it all off to the machinist, and he took a shot at making this. I set off to cut 1/2″ acrylic so that I would have a box to mount the cable reel and a motor from a hobby car. He had a 1″ piece of rolled aluminum for the motor gear.

There are ball bearings on both sides of the reel, I purchased some pins and allen screws from mcmaster carr. The belt came from a music supply store in industrial portland.

Here is the tether I cut from 1/4″ cardboard. There are also 3 little mild steel tubes that my machinist bent and flanged the inner part of the tubes so they wouldn’t cut the delicate fishing line! This piece is about 40″ long, and about 30″ wide so it will fit through doorways easily.

All together now, here are what the pieces so far look like together. I epoxied a lazy susan to connect the rail to the caddy base.

At this point I tested two component functions separately. I wired up the base with an electronic speed control, and radio control equipment. It worked very well on the track. I also purchased a few party balloons and tested the reel about a dozen times with the fishing line running through the top assembly. Also worked without problems!

In order to fit all of the ballast with a 12 ounce camera through the door I calculated out the volume of helium required, and discovered that I would need to push up the camera as well as pulling it up to get an acceptable amount of height for my shots. After looking around I discovered foamboard would be perfect in terms of rigid strength and ease of cutting. I purchased a sheet for $11, and made this by using concentric circles that followed the path of motion. This design seems to be rigid enough, especially if it has visquine tacked to both sides. Note, the front of the vehicle has two strings to help with dragging it sideways, and there is one string in the back which lets out about 30% more line per revolution. This is so the camera will be tilted as it rises for focal shots that are of interest.

As you can see here, the most dense part is near the middle, which is where my tiny sony camera will be mounted in flight and the ballast will be shaped like a V so it doesn’t interfere with the shot. all three tethers will be attached to this which will provide a rigid maneuverable base that will have visquine ballasts on top and bottom. I am still reducing the weight of this piece. It is about 8 ounces, and I need to have it at around 6 ounces.

Here is the camera I intend on using for this project. I suppose any camera that weighs up to 14 ounces or so could still pass through the door on my device. I can’t imagine this would work with a wire dangling, so it would need a film camera or a light digital camera to be effective. This one is a palm sized pocket recorder that uses mini DV as its format so there is a tape in this tiny package.

This project is waiting for the right opportunity now. I have plans to add a optical speed controller for precise adjustment. I’m also thinking of adding a lazy susan motor and midi control so that I could control the caddy through my video capture software and time the shots to music or direction.

It was an impulse scrap exercise from when I learned to cut and weld stainless steel. Made out of the material used to control REAL microwaves. This micro-pistol was just a lawn ornament for a while, but everyone that sees it can’t seem to help from picking it up to make a sound. I’d gladly trade it for a collection of all the noises people make when they play with it!