[Eric Strebel] uses a small homemade vehicle with his camera mounted on it to get great tracking shots for the intros to his videos. If the movement is slow enough then the effect is quite professional looking. But he wanted it eight times slower. We not only like the simple way he did it, along with how he machined parts for it, but the result makes it look like a hot rod, hence his name for it, the dolly hot rod. He also has an elegant mechanism for disengaging the motor while he repositions the dolly.
The are many ways to slow down a rotation. We’re assuming he was already at the minimum speed for the vehicle’s 8 RPM motor transmission and electronic speed controller. Gears or pulleys would probably be the next options. But [Eric] went even simpler, switching from roller blade wheels to larger diameter scooter wheels.
As simple as that sounds though, it led to that age-old conundrum, how to attach the wheels to the vehicle. The axle is made up of PVC tubes. So he machined square the ends of some PVC plugs and bolted the plugs to the wheel bearings. That left only to push the PVC plugs into the axle’s tubes. There are a number of ways he could have machined the PVC plugs, and the full explanation of the one he chose is best left to his video below. But basically, it involved first machining a Bondo body filler cylinder with a bolt embedded in it and then using the cylinder to hold onto the PVC plug while he machined that.
The camera, in this case the one from an iPhone 6, is mounted to an off-the-shelf robot chassis that tools around on a pair of DC motors. The camera mount uses a stepper motor to get just the right shot. A PIC32 on board the ‘bot takes Bluetooth commands from an iOS app that the team built. The dolly works two ways: it can be controlled manually in free mode, or it can follow a predetermined path at a set speed for a specified time in programmed mode.
Our favorite part of the build? The camera’s view is fed to a smart watch where [Ope] and his team can take still pictures using the watch-side interface. Check it out after the break, and stick around for a short time-lapse demo. We’ve featured a couple of dolly builds over the years. Here’s a more traditional dolly that rides a pair of malleable tubes.
[Ivan] likes to take time lapse videos. Using his 3D printer and a stepper motor he fashioned a rig that allows him to control the camera moving any direction on a smooth floor.
The dolly has a tripod-compatible mounting plate and scooter wheels. An Arduino runs the thing and a cell phone battery provides power. A pot sets the speed and [Ivan] provides code for both a linear pot, which he suggests, and for a logarithmic pot, which he had on hand. You can see a video of the results below.
We’d call it a robot, but [Eric Buijs] calls it a dolly. [Eric] bought a Makeblock starter robot kit last year, but never did anything with it. He recently wanted a camera dolly to help shoot project videos and the Makeblock hardware fit the bill.
[Eric] found that one of Makeblock’s example videos showed off a camera dolly but had no construction details. He cracked open the kit and got to work replicating what he had seen. Two 6V motors combined with a reduction gear, a belt, and some wheels, and the dolly now moves under computer control!
While [Ted] was poking around the ‘net, he came across a neat little product called a camera dolly. These are used to add an artistic flair to filming. They are similar to a camera slider but can roll around on the floor or a table and do not need to follow a track. [Ted] wanted a camera dolly but the cost of a professional product seemed too expensive for what he’d actually be getting, so he set off to make his own.
[Ted] first designed the dolly in a CAD software and printed out templates for the parts. Those templates were then transferred to plywood and cut out with a jig saw. Three inline skate wheels support the frame and allow the unit to roll around. Mounted in the center of the frame is a pan and tilt camera mount.
The extraordinary part of the build is that the angle of each wheel can be adjusted independently. This allows the dolly to do anything from rolling in a straight line to gradually traveling around a curve or even just spinning the camera in place. Each wheel mount has degree indications so that they can be adjusted very precisely as well as be returned to a previously recorded position.
Driving a carriage up and down a cylindrical object isn’t the most popular activity but that is certainly no reason not to build such a device. Check out [Ryan’s] creation that does just that, he calls it a Tubular Drive.
There isn’t much going on here, basically there are 4 wheels that grip a pipe. Two of those wheels have integrated gears and are driven by a DC motor. The remaining two wheels are idlers. When power is applied to the motor, two of the wheels spin, which then moves the entire assembly down the pole. A quick reversal in polarity brings the unit back the other way.
With those 3D printed plastic wheels you may think that traction would be an issue but [Ryan] insists that it is not a problem. The ABS wheels were treated with an acetone bath to smooth out the print layers and the distance between the wheels can be adjusted using a couple of bolts. Together that allows enough surface contact and pressure to ensure slip-free traveling.
Although the wheels were made to grip 1/2″ electrical conduit, it would be very easy to adapt this design to fit around and climb up all sorts of cylindrical objects, maybe even rope! Perhaps v-wheels with a spring tensioner system would allow for traveling on different size tubes while also adjusting for any variation in the diameter of a single tube.
[Ryan] says version two will have a linear encoder and be driven by a stepper motor. Check out the video after the break…
Similar to other rigs we’ve seen, the heart of this design makes use of skateboard wheels — they’re cheap, have good bearings, and are easy to mount. He’s created a dolly for them using a T-strap bracket, which is used for wood framing — the wheels mount directly to it without any modification.
What we think is unique about this build are the rails [Shootr] decided to use. They’re U-Post fence posts — strong, rigid, and probably one of the cheapest forms of processed metal you can buy. To hold them together, he’s using a threaded rod with two pieces of 1/2″ square steel tubing, bracing the fence posts. This wedges the dolly in between them with just enough slack to slide smoothly back and forth.
The other method of making a camera slider like this is using tubular rails, which also allows you to add a curve in your camera track. And if you’re looking for a precise, 2-axis camera dolly… you should check out this one!