Smooth tracking shots over uneven ground can be infuriating, ‘I just want to move the camera from point A to point B!’. A dolly and track can only help with small bumps, what about that river? And how about the steep slope over there?
Luckily the solution is really easy. Here’s a zip wire dolly which can be put up anywhere there’s trees, buildings or big bits of scenery to tie it to. The hardest part of a build like this is the head, i.e where you attach the camera. Clearly you’ll want to be able to execute smooth pans and tilts as you track. We’ve cheated here by designing in a socket that lets you attach not just the camera but the whole tripod: which also lowers the centre of gravity and helps stabilize the rig!
Time (1 hour – 30 mins)
Things you’ll need.
Steel cable 3mm x 10m (anything above 2mm is fine: buy as much length as you need.)
Offcut plywood (3mm or above is fine)
2 x lawnmower wheels
(these can be bought at most DIY shops: the bigger the wheels the better).
4 x Carriage bolts and nuts
(these will be your axles. They need to be longer than 40mm and as close as possibly to fitting the bearings in your wheels).
A workclamp (see picture: this is what your camera will hang from. It needs to be sturdy enough to hold a camera and the jaws need to open wide enough to comfortably fit a camera into).
1) Prize the tyres off your lawnmower wheels. Hey presto: you’ve got pulleys! Use the sandpaper to smooth out any plastic lumps left from the moulding.
2) Cut two pieces of plywood, approx 50cm x 20. Make sure there’s enough space to fit your wheels. The further apart they are, the more stable your rig will be.
3) Drill holes for your axles at least 10mm in from the corners.
4) Slide the carriage bolts through the holes, fix them in place with a nut.
5) Slide your wheels onto the bolts with a washer on either side.
6) Fix them in place with a nut on each bolt and tighten them enough to allow the wheels to turn freely.
Great, you now have the dolly part of the rig. Now for somewhere to hang the camera. If you have the space, put up a short length of cable to hang the rig on while you work: otherwise use your imagination.
8) Drill a hole through the lower jaw of the clamp.
9) With a handsaw or jigsaw, cut out a horse-shoe shape piece of plywood, that roughly follows the shape the ‘neck’ of your tripod, just below the head.
10)Drill a hole through it and bolt it to the bottom jaw.
11) Hang the clamp on the rig as shown. Make sure that the cable won’t catch it as it passes between the wheels and that it’s balanced enough to not tip the whole rig off the cable.
12) Drill a hole through the upper jaw of the clamp and through the middle of the horizontal part of the rig.
13) Bolt the clamp onto the rig.
Lovely! You now have a smooth-running wire dolly that would make David Attenborough’s mouth water. Now the fun bit:
14) Find two trees/pillars/rocks etc and set up your wire. BE VERY CAREFUL HERE. The tighter you can get it the more stable the path of the camera will be, however this requires a lot of tension: often more than 100kg. Don’t attempt to tie it to drainpipes, electrical conduits or vehicles. Or Animals. Ideally get a burly friend to help.
15) Now hang your rig on the cable.
16) Finally, hang your tripod and camera on the rig, securing it with wire.