Cheesycam DIY Auto Reverse Polarity Motorized Video Slider – Update

A short while back I shared a simple way of wiring up a motorized slider to move back and forth continuously (original article found here). No fancy software or programming, just a basic electro-mechanical system. There are many benefits to having this 'auto-looping' feature. One benefit is that a 'B' camera can continuously slide back and forth without the need for an additional operator, and another benefit is for TimeLapse projects that can continue to capture footage without stopping at the end of a rail.

Throw a few of these around an event and you'll have some great Dynamic Camera Movement footage to cut to without hiring additional crew.

I decided to update the project because some people couldn't quite figure out the circuit. With these new instructions using a numbered socket block, anyone should be able to follow this build, even without understanding the circuit. Hopefully this clears things up for some of you out there, and for those who may have been initially intimidated by the wiring.

Looping-circuit-auto-reverse-polarity_01 copy
Color coded wiring diagram - Click for larger view

I would set this up in a test scenario (loose parts on a table), and once you have it figured out, you can start attaching things to your actual motorized slider. Remember that this is all based on a very specific DPDT Relay + Socket Base Kit (found here).

Step by step Check List for you to follow on building an 'Auto Reverse Polarity Circuit'.
#1 Wire connects to 'NC' on Switch A
#2 Wire connects to one side of the Motor
#2 Wire (also) LOOPS back to Terminal #3
#3 Wire LOOPS back to Terminal #2
#4 Wire LOOPS back to Terminal #7
#5 Wire connects to 'NC' of Switch B
#5 Wire (also) connects to NEGATIVE on Battery
#6 Wire connects to POSITIVE on Battery
#6 Wire (also) connects to 'NO' on Switch A
#7 Wire LOOPS back to Terminal #4
#7 Wire connects to 'C' on Switch A
#7 Wire connects to one side of the Motor
#8 Wire connects to 'C' on Switch B

Remember to start this build by having parts loose on a table. You should know exactly what side your switches should be (left/right) so that the Slider is bouncing back and forth properly. If it's still not working correctly, try swapping the wires on your motor. If you have it swapped it will turn in the opposite direction. This circuit is designed specifically for the motor to turn a certain way.

Hopefully this has been helpful for those struggling with this project...

How It Works:
Two 3 Pin NO+NC Momentary Micro Switches (as found here) at each end reverse the polarity of the motor each time they are triggered.

DIY Slider micro switch 3 pin NO NC
Example of 3 pin NC/NO Momentary Micro Switch

A 12V DPDT Relay (as found here) is either 'Always ON' until the slider reaches the opposite switch which drops power to the relay.

12V DPDT Relay DIY Slider Motion Control
12V DPDT Relay with Socket Base

In one direction, the relay is technically 'STUCK ON' by way of a tricky little feedback loop in the circuit. To turn the entire slider on or off, i'm just using the switch from the battery. In this example, i'm not using a speed controller, but one can easily be added.

Additional Parts Suggested for this Build.

5.5 2.5 DC Male Plug Tip
DC Tip 2.5 5.5
12V Super battery


62 thoughts on “Cheesycam DIY Auto Reverse Polarity Motorized Video Slider – Update

  1. Ron DIYer

    I really appreciate all the work you post helping the whole community of DIY camera world! I also followed this and got my speed controls from Servo City and got it working. Problem that was stated earlier about low current not triggering the solenoid in the relay switch. I found it to be more responsive if you modify the spring to a real soft extension spring. Makes it more responsive to lower voltages. Still it's tricky with the speed controller. But it move slow enough for 140 seconds over 24 inch travel and trigger the reverse switch. Great help from your website to get this far on my project. Thank you so much!!

  2. Tom40422

    Thank you Mr CheesyCam!
    I used your directions and setup worked great the first time I tried it. Like one of the other comments, I would like to try using a timer relay and be able to have a controllable pause at each end of the slider. I found this Omron H3Y-2 device with 0-60 secs of delay. When I plugged it into the existing relay socket, it didn't work. Of course! Ha! I contacted Omron to see of they can help.
    DPDT Relay on Amazon I am using:
    Omron H3y-2 Timer Relay:
    If you have time to help, I would really appreciate it. Maybe one of the other people who commented can help, too.
    Thanks again for the great tutorial.


    I solved your problem Josh. You are using too low of a voltage source. Try using a 9 volt or higher and the circuit will work. This is not a great design for a low voltage circuit. It is perfect for what I am wanting though. I used a 3 volt battery at first and the switch B only stopped the circuit. Got pissed off and then tried the 9 volt battery. The 9v Battey made the circuit work perfectly!


    I have the same problem Josh has. Switch b does nothing and switch A only stops the car and does not relay reverse the motion as designed. I strongly believe this diagram to be innaccurate at some point.

  5. kenny west

    Just wanted to say thank you for posting the instructions, etc.! I was able to use yours and modify to control a linear actuator where it retracted, waited 20 seconds and then expanded again. Using as a remote trunk unlock with two Directed Electronics 528T relays (they are DPDT relays with an adjustable timer which can be set to either send + or - for a prescribed time or pause before sending + or -.


  6. Fred

    Great tutorial, my diy rig works perfectly. Only waiting on an update on how to wire the speed controller to the rig.

  7. Josh Witt

    Still no luck. Everything same as diagram but when micro switch is hit motor just stops while switch is on then starts upon release in same direction. Only thing different is I'm using a different motor. Any ideas?

  8. Ricky Vargad

    I have to say that this tutorial was great
    Good job!
    I have a quick question. Can you tell me how to
    Connect a PIR sensor to this circuit.
    The sensor has 3leads , vcc,output and ground.
    Thanks again for your help.
    Ricky v.

Leave a Reply

Your email address will not be published. Required fields are marked *

RSS Feed Widget

Top Selling Drones