Sliders have caught on in popularity recently with the lightweight DSLR camera explosion. Some say that the effect is overused – perhaps it is, but in my mind adding some slight subtle camera movements to your shot adds a tremendous amount of production value. And when it comes to subtle movement, sliders deliver the most bang for the buck, both in terms of cost and ease of setup and use.
I’m going to demonstrate how to add a crank mechanism to an existing slider such as the indieSlider which I’m using here. A little bit of ingenuity and you should be able to adapt this to any slider.
But like all things on this earth, everything good thing comes with a drawbacks. A basic slider’s lateral movement is based on the human’s ability to smoothly push the slider carriage back and forth. Having done this a few million times, it’s not always so easy to get a great take out of the box. Fatigue, and angular physics all play into how smooth your shot will be.
So I wanted to take the human element out of it – or at least change the way the slider is powered. I wanted to centrally locate how the carriage is moved.
The following diagram lays out how I mechanized my indiSlider – this technique can be reworked to apply to any slider you have.
Here is a list of specialty parts you’ll need:
- 1/4″ Precision Shafts (which you’ll cut into pieces)
- 1/4″ 0.08 MXL Pitch Timing Belt (enough to span twice the length of your slider plus a little bit more)
- 2 Timing Pulleys with Flanges
- 2 Metal Collars
- A Handwheel (bore .25″) You’ll need to drill a locking screw with these wheels.
- Nylon bearing Collars (available at your specialty hardware store)
- 4 Aluminum 1/4″ spacers (1 inch long) – for lifting up the end blocks of the indiSlider
- 4 2 inch bolts to anchor the end block.
Tools you’ll need:
- Drill press
- Drill kit (capable of drilling through metal)
- Measuring tape
- Tap kit (for drilling a locking screw into the wheel)
- Hexwrench kit
Here’s a really quick and basic run down of the process to assemble the mechanized slider.
First thing you need to do is drill a hole for the drive shafts on both the powered and the none powered ends of the slider. See the diagram above for the placement of these holes. The hole should be slightly larger than the 1/4″ shaft and enough to accommodate the nylon collar bearings.
Now you can remove both end blocks and remove the carriage sled. Using the diagram above drill two holes for screws and install screws so they hang just below the carriage but not low enough to hit the floor of the slider. You may need to inset the screws slightly if you have a big pan-tilt head on the carriage as the screws can interfere with the head.
Place the carriage back on the slider.
Next, assemble the shafts as shown in the diagram and fit them into the holes that you drilled earlier. Assemble each end so that it looks like the diagram above (note that only one side will have the handwheel – the other side will be free spinning).
Now that your ends are assembled, it’s just a matter of installing the timing belt. The neoprene timing belt listed above does not have much give but it works very well without any noticeable slipping. Make a loop on one end of the timing belt and hook it to the screw on one side of the carriage. Run the belt over the pulley, back under the sled, over the other pulley and attach the other end to the other screw under the carriage. I use a combination of tape and staples to keep the loops in place.
As a note – the hand wheel listed above has a bore of .24″ – you’ll need to widen the bore to .25″ to get the drive shaft to fit. You’ll also need to drill a hole for a locking screw so that the hand wheel doesn’t slip while in operation.
And that’s it…Having the mechanized slider opens the doors to all sorts of possibilities – including adding a step motor for controlled timelapse photography.
If you’ve priced out the items above you notice that this mod is a decent investment. At around $120 or so, it’s still far less expensive then $1000 crank sliders out there.
If you attempt this project – leave a comment below on how it worked out of you!