Friday, November 22, 2013

ServoCity Actobotics Channel Slider Project: Part I

Even though I have a slow motion ladder dolly for moving time lapse projects, I've been thinking for a while that I would invest in a smaller slider for use with my smaller cameras, like the GoPro or Sony NEX-5.  I have been working on modifying my larger dolly to be flexible so that I could use it on different width ladders, but still wanted something portable. has some new channels and parts from Actobotics, which gave me the idea to redo the larger dolly.  As an impulse, I also ordered the Channel Slider Kit, for more of a portable solution.  You can think of the Actobotics parts like an Erector Set on steroids.  It took about an hour to assemble the original kit. has excellent video tutorials on how to put the slider together.

I also ordered the 0.5 RPM gear motor, which takes just over 11 minutes from end to end using full power. Re-purposing my Potentiometer from my slow motion ladder dolly, I was able to slow the transition from end-to-end to about 32 minutes.  The slider kit came with some plastic feet to stabilize the slider rail. Unfortunately, they are not wide enough and do not have any sort of anti-skid traction.  I re-purposed these feet later in my build.  (See part II of this build thread to see how I replaced these feet with a solution that works with a tripod)

I also upgraded to the full size Channel Slider A (585550), versus the ones that came with the kit.  I wanted to be able to use heavier cameras than just a GoPro, and also potentially use 2 cameras at the same time.  I felt that these have more stability than the original channel sliders.

I added a 1/4-20 Screw Plate to the top so that I could easily add a mini-ball head or other 1/4" accessory to the top.  

Here's a picture of the basic slider kit with the upgraded channels holding a Sony NEX-5.  This camera is right on the edge of being too heavy while using the original feet to stabilize the slider.  I decided to make some upgrades on how to mount the slider.

Since I'll be using the same battery and Potentiometer from my full size slow motion dolly, I needed to make some changes and add some quick release connectors.  I tried to clean up the cabling from the original build, and now I just plug in and it's ready to go.

In my original slow motion ladder dolly, I had added limit switches so that the dolly would stop when it got to the end of the track.  I thought it was a good idea, as there is potential of burning out the motor if you don't stop it when it gets to the end.  I used the same concept and wired some simple limit switches on each end. This does reduce the track span by about an inch, but it will prevent issues.  This way, I can walk away from the slider and not worry about if the motor will stop or not when it gets to the end.  I also added an additional 1.50" channel to the bottom to mount the limit switch and add a 1/4" screw plate to the I can mount the slider to a set of light stands, tripods, or jobypods.  

Here you can see the one side of the slider attached to a light stand mount, and also the limit switch underneath.  The 90 degree dual-side mount (585470) was re purposed, as they were originally used for the plastic feet.  I used them to attach the limit switch which will stop the dolly when it gets to the end.

Attached to 2 light stands, and  multiple cameras attached to the channel slider.  I used a Quad Hub Mount E (545452) on the bottom of the channel slider so that a second camera could be attached, for an even simpler method of attaching a 1/4" hex bolt, which worked nicely with the GoPro HD Hero tripod mount.  I used a 1/4" round screw plate with a 1/4:" hex bolt to attach to the top of the slider with a mini- ball head.  

One challenge with the limit switches is that once the channel sliders turns off because it hits the switch, there is no way to reverse direction without power.  I wired in a couple of extra power connectors, each with different polarity directly to the motor, so that I could back the channel slider off the limit switch when necessary.  It also allows me to to run the slider without the Potentiometer and directly to 12V power if I need it.

I'm currently running a 0.5 RPM gear motor, and have a couple of other faster models, but wanted this slider to go as slow as possible.  With the Potentiometer, I was able to get it slow enough to traverse the channel in 32 minutes, so pretty slow for a 2 foot slider.

You can see the old feet re-purposed as mounts on the bottom of the channel slider, which is what strikes the limit switches when it gets to the end of the track.  

Since you can use pretty much any tripod, jobypod, lightstand, or anything with a 1/4" attachment bolt, you can get this thing pretty sturdy and stable.  With a bigger ball head, I wouldn't hesitate to put my larger dSLR camera on this slider, asssuming that the mounting points on each end were used.  Now that this is complete, I plan on ordering another 24" channel and mounting it on the bottom so that I could use a single 1/4" round screw plate to attach the entire slider via a single tripod.  


I'm a huge fan of DIY projects, and this slider kit from ServoCity allows you to get your creative gears moving while still providing a professional product you'd be proud to use in the field.  The trouble with the Actobotics parts are that it can get expensive very quickly, so it pays to plan out your parts list.  I spent way more than I wanted to on parts for these projects. I ended up making 3 purchases from ServoCity within a week to get everything I needed for a couple of these projects, and still need to make another order to complete the build.  They do offer a discount codes if you like them on facebook or twitter, or promote them through a blog post.  This can get you a coupon to use on future orders.   Someday, I'd like to figure out a way to program the this slider to reverse direction continuously when it got to the end of the channel, but I'd need to probably learn more about Arduino or something similar first.  I'd like to see them come out with longer channels, as the longest is currently 2 feet.  I'd love to have this in a 4 foot slider. (Hint, hint...)


  1. Could you link 2 X 24 pieces of channel with either their dual screw plates or aluminum beams?

    I want to make a 48" slider as well and I don't have this kit yet so I don't know if this would work. I was thinking about using 3 aluminum beams on the bottom and open side and using the channel slider d. I don't think there is space to use the channel slider a and have the beams/plates and screws but I'm not sure. It also may fit on the inside. I haven't gotten my hands on this stuff yet so I don't know.

    Do you think it would work without flexing? I don't know how strong this stuff is.

    You can get a longer belt at I just saw another diy vid with a 48" slider. They got a belt from there that worked with the servocity pulleys.

  2. Sorry for the delay in responding. I think it might work, but would suggest using the slider parts that encompass the entire channel. If you test that, I'd be interested in knowing how it turns out. The channels are light, but strong.

  3. How is the moving camera mount connected to the pulley belt? Is it going through a pulley wheel or is it fixed to the mount static. Thanks.