Thursday, January 9, 2014

ServoCity Actobotics Channel Slider Project: Part III

Gear Reduction Auto Reverse Time lapse Slider

I plan on using this super slow motion camera slider for time lapse sequences.  Part III of this series will focus on the addition of the DPDT Power Relay and limit switches to make the slider go back and forth as slow as possible.

Part II: Adding Mounting Channel

Finalized Channel Slider with Micro Limit Switches and DPDT Relay Mounted on MeFoto Tripod

Slow the slider down...

For the final modifications to the ServoCity Actobotics Channel Slider, I have added a pinon and hub gear to reduce the speed of the slider, and a DPDT relay and limit switches to make the slider go reverse direction when it gets to the end of the channel.  I originally tried a 32T pinon gear with a 64T hub gear to slow the slider down.  I had to extend the channel by 1.50" to accommodate the gears.  

Without any gears to reduce the speed, the slider took 11 minutes one way to traverse the channel.  With the gears, there wasn't a dramatic change in how fast the slider moved across the channel, around 24.5 minutes side to side.  I want to be able to use this for dramatic time lapse sequences, so ordered a 16T pinon and 80T hub gear to slow it down even more.

Using this new gear ratio, the slider now takes 61 minutes to traverse the 24"channel one way using a .5 RPM gear motor.  In the original design, I had limit switches to stop the slider when it got the end to prevent motor burn out.  Ideally, I wanted the slider to go back an forth.  I saw a blog post on where they figured it out using a 12V DPDT power relay, and posted the schematics here.  I cannot take credit for this wiring wizardry, as I just followed the diagram.  The nice thing about having the second, lower Actobotics channel, is that I was able to mount the relay and all wiring out of the way. also just released their own limit switches and mounts, so I replaced mine with a pair that mount to the channel.  Having the gears mounted to the end of the track reduce the slider throw by 1/2", but reducing the speed of the slider was more important for my time lapse needs.

The new micro switches mount cleanly, and work great with the channels.

In addition to the 1/4" screw plate, I added a 3/8" screw plate to provide maximum mounting options.  The black section is velco to hold the 12V battery.

Using the slider in tandem with a Camalapse rotational mount, here is a sample time lapse sequence to test the slider.


  1. Great post, I came here via the CheesyCam link. Do you have any information on the motor you used? That is the only part left I need and I'm ordering via eBay. Not sure which is best... Thanks G

  2. I am wondering what motor to use too. Which one ? There are so many of them out there.

  3. SOrry for the delay in responding. I used the slowest gear motor that they had at Servocity, and then used the gear reduction to make it even slower.