Jan 29, 2021

Tony's Motorized Slider (behind the scenes)


This project like many others reiterates the adage that necessity is the mother of invention. I needed to solve a problem.  As a solitary filmmaker, I fill all the roles, director, cinematographer, screenwriter and so on. I am also the talent and that creates a major problem.  It is difficult to control camera movement while on camera!

I particularly like the shots from a camera mounted on a slider, especially reveal shots. For my birthday my wife had given me a very nice slider. I used it with my Samsung S7 and liked how smooth it was and the shots I was able to take with it. BUT, I was not in any of the camera shots because I had been operating the slider.
An easy solution would have been to have purchased a motorized slider for several hundred dollars. The cost was prohibitive for me. 


When I first got the idea to motorize the slider I looked for a motor in my spare parts bin with no luck. An inexpensive rechargeable drill would provide the motor. But I would have to disassemble the power tool to adapt it to a task for which it was not designed. With a hacksaw I cut the plastic case apart. I used a hacksaw because it had fine teeth and cut carefully to avoid cutting any wires. Since the reduction gears used the plastic body for a gear case they fell out and I had to put them back in.  It was sort of like putting together a puzzle. The battery pack, switch, and charging circuitry were cut free of the motor. 

In order for the motor to move the slider I had to mount to the slider track. I had to fabricate a bracket of wood to match the curvature of the drill motor body to the slider rails. Initially I intended mount it with screws to the slider. But I would need to drill and tap holes in the slider. I don't have a drill press or taps.  So...I resorted to wire ties although I would lose 6 inches in slider length. I scrapped the drill  momentary "on"  and reverse rocker switch. A simple continuity check with a multimeter determined where to insert a switch from my junk bin. An old 35mm film canister was used as a switch enclosure. Some old multi conductor phone wire was used to wire the remote switch.  The phone wire also provided the wire needed to locate the battery at the opposite end of the slider. I located the heavy parts of the system at opposite ends of the slider to balance the weight in case it was installed on a tripod. One final item had to be added. I had a problem. How to attach the movable slide to the drill motor. I could have used monofilament fishing line. Or maybe cotton string. The fishing line was too stiff. The string was not durable enough. But dental floss was strong, flat, and waxed.  It was attached to the movable part of the slider and the motor. I have used dental floss in other repair projects. Everything worked as expected and at a price I could afford. One caveat about the operation of the slider: it is extremely noisy!

I am a believer in close enough technology and this is a good example.









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