Dana Dolly V3 Beltless integration - with your Spectrum ST4/ST4.3 - Sensor and Marker Install

If you ordered your DDV3 Beltless Dana Dolly to work with the spectrum ST4/ST4.3 head, we included a sensor board, marker stickers, and a dongle that sits between your spectrum and the sensor board.

The sensor board/stickers will work with certain firmware's for the spectrum ST4 to calibrate and read the sensors during certain shot types (ping pong) and auto adjust.

Sensor Board Install

1. Get your Spectrum on the right Firmware!  As of the writing of this article on 10/20/2025, this is RC008_24_B3, but look out for release notes to find the most updated version for the DDV3 kit.
2. Get your motor installed to your Dana Dolly. The first 30 seconds of this video shows it with our conductor.

3. Power up your spectrum and make sure your firmware is what you think.  Go to Settings -->(down to Page 5/7)--> I/O Port.  Set I/O port to Ext. Trigger.  Now your spectrum is ready to receive the digital signals from your sensor board.   
   Updated October 2025 - Since there are hardware differences with some older Spectrums, we have also created a "Ext. Trig Reversed" option that can help if your end stops are not adhered to correctly.  If this is your first time setting up.  Try "Ext. Trig" first.

   
    

4. Check that you everything you need to install your beltless Dana Dolly in your eMotimo kit.  It should include:

   

5. Figure out how your USB power source for the sensor board. DO NOT USE TILTA DTAP TO USB C cables. These unregulated cables can provide up to 16.5 volts of to USB devices and will break your sensor board, maybe your camera, and anything else that expects USB C standard power.   Regular USB power source to USB-C type plug will work.  A 1.5 foot USB-A to USB-C or USB-C to USB-C cable will work, depending on where you are getting the power.  Since most V-Mount and Gold Mount packs have convenient outputs for USB-A and even USB-C, start there for your power source. The other end needs to be USB-C to plug into the dongle. The dongle negotiated 5.0V power from proper USB sources.
   
6. This shows how the dongle is hooked up. You provide power to the the dongle over USB-C.  You connect your sensor board to the dongle using the 4 wire locking connector (on the left of the image).  You send signal to the spectrum's i/o port over the 3-lead i/o cable (on the right of the image).
    
7. Here's what it the dongle looks like all hooked up!
    
8. Make sure that the 3-lead i/o cable is plugged into the right port!
9. Once you have powered the Dongle and hooked up the sensor board, both LED's should light (green and red).  If not, make sure your I/O port is set correctly in the above steps. 
   
10. Attach your sensor board to the DDV3 Integration Kit, finger tight or very lightly using the single M4 screw. The channel is oriented so that it's touching the carriage mount. Wires are on the outside.
    
11. Reposition the sensor board as high as possible on the mount while being level (parallel to the track).  Lightly snug the screw down.  Did one or both of the sensor lights go out?  Good.  LED's are off when we get reflections from the track surface!

12. If you aren't already, disengage the Drive wheel (click it out of place) so you can manually move the Dana Dolly.

    

13. Move the Dana Dolly left and right while watching the Red and Green LEDs.  If both are off for the full length of the track, you are good!  If not, then we need to get the sensor board closer to the track so that the LED's remain off while the dolly traverses the full length of the track.
14. Loosen and reposition the board lower and level until both LED's turn off when the screw is tightened, and the board is parallel to the track.  Below shows the lowest the sensor board placement (usually not necessary).  Watch out!! - don't lower it too much or the screws or sensors can make contact with the track or marker stickers.
     
15. When your LED's stay off while manually moving over the clean track, lightly snug the mounting screw to lock in the sensor board position. The stalk holding the sensor board is plastic, so resist the urge to overtighten as this can break the part.  Hint - grab and use the Short End end of the wrench to give yourself less leverage.
    
16. Now you can re-engage the drive wheel. Pull the spring plunger and twist it 90° to lock it out of place. The drive wheel will drop down and make firm contact with the track.
17. Clean up and wire routing:  We designed what we think is a pretty neat little housing with Velcro wire wraps to help wire routing and mounting.  Here's what it looks like hooked up as intended.  Note the motor wire is meant to be fixed to the back of the housing so that the wires connected to the motor pod and track sensor are routed together and out of the way.  We like to put the dongle on top of the Dana Dolly and run through a couple shot types to make sure things will stay where they are supposed to during the shot.
    
     

Marker Sticker Guidance

Depending on your shooting style, you may not need to use all of the sticker included with your beltless Dana Dolly integration kit. Using the fewest marker stickers necessary will simplify your setup and allow you to work more efficiently.

1. Single-Pass Shooting

   If you are using your motorized Dana Dolly for single-pass shots, there is no need for marker stickers or even the sensor to be installed.

2. Ping-Pong Interview Shooting

   For ping-pong shooting, only one mid point marker sticker needs to be installed in the middle of the track. Give the dolly 1 foot of buffer space on either end of the ping pong move. The dolly will make small corrections after each pass (this will be improved in future firmware versions so corrections will be unnoticeable during the dolly move).

3. Remote Installs

   For remote dolly installs where the dolly is out of sight from the operator, end stops and marker stickers should be installed.

Marker Sticker Install

When installing stickers its important to understand two dimensions:

Left/Right position of the sensor is what most people focus on, but there's also what part of the round speed rail you use. There are two sensors on the sensor board that straddle the centerline of the speed rail.  This centerline (highest point of the rail, running the length) is important as you want the marker stickers placed so both sensors can clearly "see" the black portions of the stickers. 

1. Placing the Left End Stop marker - Move the Dolly to the left hand stop, and mark the track with a pen or tape to indicate where you want your left stop to be.  Place the sensor sticker on top of the track so that when the Dolly is travelling left both LED's will turn on 6 to 8 inches before dolly would run into the ends.  Then ends up being about 15-16 inches from the left side 
   
2. Placing the Right Stop Marker - Move the Dolly to the right hand stop, and mark the track with a pen or tape to indicate where you want your right stop to be.  Place the marker sticker on top of the track so that when the Dolly is travelling right both LED's will turn on 6-8 inches before dolly would run into the ends. Then ends up being about 13-14 inches from the right track end.
   
3. Place the middle marker between the two end (exact position doesn't matter) - place the sticker so the middle centerline is on top of the track. You want this centerline to be between the two sensors (straddling) as shown.
    
   Completely seal the marker sticker to the track so nothing is sticking up. (above pictures is not final!)
    

Testing marker sticker placement

Now you are ready to test your install.  You will do this by looking for the LED's that are indicated as you pass over these markers.

1. Manually move your Dana Dolly left and right.
2. During most of the track, the sensor board leds should be "unlit" This is actually "seeing" the track, well actually the reflection off the track.  If not, you need to adjust your sensor board to achieve this.
3. Test the left stop - SLOWLY (1 inch per second or less) travel left to run over the End Point Sticker. It should indicate both lights (Red/Green) and then have its left stop auto set.  
4. Test the right stop - SLOWLY (1 inch per second or less) travel left to run over the End Point Sticker. It should indicate both lights (Red/Green) and then have its left stop auto set.  
5. If you want to reset the stop, the options button on your controller will clear the stops
6. If you get stuck in a stop, Clear the stops with Options.  our spectrum needs to change its setting from 
   Settings -->I/O Port: Ext Trig. to:
   Settings--> I/O Port: Ext Trig. Reversed (new option in the Spectrum's latest firmware)
7. Test the Mid Point marker - the Green LED indicates sensing the back black portion of the sticker and the Red LED indicates the front black portion of the sticker.  Both should clearly turn on and off when passing over their respective regions.  It is this marker that we must pass over during a ping pong shoot.

If all tests well, your Dana Dolly is ready to shoot.