This is a trial and error / design and development process which I followed in developing a camera slider for creating time-lapse video clips on my DSLR camera.
The idea came from using standard Aluminium extrusions I have available at hardware stores, and create a slider chassis / dolly which is able to slide along this extrusion. The Aluminium extrusion is what builders use for creating a smooth screed on a floor, or plastering a wall. It is a perfect hollow rectangular extrude, of approx 70mm by 20mm, and is available in various lengths between 1m, and 4m. The wheels which I found which are suitable are standard Hillaldam shower rollers, which ended up working perfectly.
The process of development saw the following needing to be designed, tested, and then prototyped:
1. Slider Rail (standard Section)
2. Camera Dolly / Slider (rollers attached to a bent metal chassis)
3. Motion Control: this was the most tricky and takes up most of this instructable. It illustrates how I developed and tested a standard geared motor, with a gearbox... which didn't work well enough. After this, I attempted utilising a stepper motor which is controlled by an Arduino Uno board which worked much more effectively. I am unable to provide set plans which you can follow, as my design depended heavily on the resourses which I had available to me (South Africa). The availability of components to me is not as diverse as in the US and Europoe, and please keep this in mind when commenting.
For the planning and design work, I used Corel Draw. This is also what I used for designing the cogs and gear layouts which were lasercut.
The designing of the gears was done with the assistance of one of the most useful online generators, being Woodgears.ca, This allowed me to save the files as HPGL, and import directly into Corel Draw.
With regards to the the actual time-lapse clips, this is all done with Magic Lantern, which is installed on my Canon 500D DSLR camera. It allows me to utilise the incorporated Intervalometer for taking timelapse images. Furthermore (my favorite) is to film video and override the initial 30 frames per second and make it film at one frame per second. When it plays back, it is 30 times normal speed which is extremely effective. This needs to be compensated with a Neutral Density filter, and Exposure compensation (with Magic Lantern).
The first idea I had was to use a geared motor (30 RPM if I am not mistaken) to drive a set of gears, which reels a spool of fishing gut. This is to slowly drag the slider along the rail.
Required: Geared Motor (12V) & 12 V battery.
Perspex: For cutting the gears.
Bearings: Friction fit into holes cut within the gears.
Bobbin: to wind up the fishing gut onto the output drive.
And fasteners for assembling.
I wont go into too much detail here, as the outcome was unsatisfactory, ineffective, jolty, frustrating, and still far too fast. There was no area for adjustment, and I went back to the drawing board (CorelDraw).