[Peter] wanted a camera slider and found some inspiration on the good ole ‘net. He then gathered some parts and came up with his own design. We’ve seen camera sliders made from roller blade wheels before but never one that uses skateboard trucks as the carriage! On each truck axle are 2 bearings spaced apart without the skate wheels. Each pair of bearings rides on one of two 48 inch long closet rods supported between two push-up stands. The top portion from an old camera tripod makes a handy mount that allows adjustment of the camera’s aim.
Some camera sliders are manual operated. This one, however, is lead screw driven with a goal of keeping the camera moving at a constant rate. A disassembled hand drill provides the motor, gearbox and speed control necessary to turn the lead screw. Although it works well at slow speeds, [Peter] admits that it becomes less usable as the speed increases. This is mainly due to the 5/16 inch threaded rod lead screw oscillating and whipping around after reaching a certain RPM. If you stick with a straight run, a belt-driven system might make those faster movements more smoothly.
Put the lead screw in tension. With a stout bracket on each end supporting an angular contact ball bearing and the rod tensioned it won’t whip until a much higher RPM is reached.
Then the rails flex…
The problem is rather that those long threaded rods aren’t straight to begin with. You’d need a hell of a tension.
Go back to non-slip tires and drive them with spring grabbing counter rotation. Geared stepper.
Now you are ready for extending the line any way. Curves, excitement.
Would something like this be steady enough for a 3d printer or a CNC mill?
For a 3d printer I would give it a yes. For a mill it depends on the material you are planning to work work with. For foam or balsa it sure is ok.
I had thought the same thing when I saw the picture… Possibly. There are machines that utilize bearings on “gas pipe” with angle iron and skate bearings… But those bearings are flat against the pipe not riding the edges like this is.
I wonder if a groove could be routed in the center of a scateboard wheel the diameter of the rod/cylinder.
That’s called a ‘v bearing’. Well, close enough.
Take power from the rails, mount a motor with rubber wheels inbetween the rails for motion, and mount a DMX chaser driven by a wifi enabled µC module to get total motion control
Couldn’t you use a belt? Fixed to the ends and wrap around a gear so the camera truck turns a gear and the belt is stationary (so you don’t have to buy a 9′ loop of XL belt)
Yeah that’s pretty common, this sort of thing: http://www.bg-cnc.com/wordpress/wp-content/uploads/2008/09/belt-5.jpg
Downsides are your motor needs to be on the moving bit (adds weight), plus you need to run a cable for power & control (not too difficult).
Better performance than threaded rod, still has a few problems over long runs with belt rebound etc.
Using the skateboard trucks is clever, cuts down the fab time by having the nicely bearings lined up for you.
Why does the motor need to be on the moving bit? Fix the motor at one end, use an open belt, and fix both ends of the belt on the moving carriage.
Better yet, use a spool on the motor and Spectra fishing line. This project is well down the budget road, no reason to ruin it with expensive belting.
Because you halve the amount of belt you need, plus less belt = less stretch etc.
Plenty of people use a loop with the motor at the end (my lasers do).
Cable drive (fishing line) is basically the same as belts. Tensioning can get a bit fiddly.
Most things work fine until they hit a limit, like threaded rods whip as the RPMs go up. Then you try belts, and rack & pinion after that. Or clamped rubber wheels if you can get positioning to work accurately.
Nice! I was going to do something similar with 1/32 scale slot car wheels, but ended up going with plastic bushings on 1/4″ rods.
for extended use you will notice a flat getting worn towards the centre of the rails, you can rotate the rod in it’s place every 6 months or so to get a bit more life out of it… that is more a problem from continual oscillation (manufacturing) so you might get away with it here.
They’re not only using skateboard trucks, but also skateboard bearings…