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RT MOTION

Discussion in 'Follow Focus' started by ross cairns, May 15, 2017.

  1. ross cairns

    ross cairns New Member

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    After using an RT Motion 3.1 FF system with thumbwheel successfully with M15, I upgraded to the Movi Pro. Bottom line is it doesn't work with the Movi Pro, apparently due to the 'voltages' being put out by the Pro causing the RT motor to jitter uncontrollably. Wondering if anyone else has the same problem and if they found a fix.
     
  2. Graham Futerfas

    Graham Futerfas Well-Known Member

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    Hi Ross, can you please describe in more detail how you're connecting the RT Motion in to your system? I'm not that familiar with the RT Motion system and I find their website frustrating when it comes to offering useful technical information. Do you use the 3.1 Receiver unit to drive the Motor? Or do you just have the Thumbwheel connected to the Motor directly and then get power to the Motor somehow separately?

    The reason I ask: The Movi has 3 D-Taps. One is for Cameras and allows for 6 amps of current draw. The other two D-Taps are for accessories and only allow for 2 amps of current, and some Follow Focus systems struggle with this. None of these D-Taps should be causing problem with 'voltages' because they're pretty close to 12V.

    Sometimes I have to use separate LiPo batteries to power my Follow Focus receiver because of the current draw. I use the Freefly M15 batteries along with their D-Tap power adapter, and I find them pretty convenient. Just use bongo ties to attach them to the Movi. It normally delivers between 15 to 16V, but these accessories are typically tolerant of that.
     
  3. ross cairns

    ross cairns New Member

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    Hi Graham. Thanks for diving in. I'm powering the receiver separately. Have options, eg D-Tap from a plate on Red Dragon or D-Tap from another plate supplied by a BP-U60 battery. In any case these and the D-Tap from the Movi power the receiver just fine as in all cases there's no problem with using the wireless 'main' FF controller. The problem comes when using the Thumbwheel which is connected to the receiver via a cable into the aux port on the receiver. The suggestion from RT motion is that the Pro is kicking out interference that messes with the aux input on the receiver and thus sends random control info to the motor. Everything was just fine with the M15, the only change to the formula being the introduction of the Pro.
     
  4. Graham Futerfas

    Graham Futerfas Well-Known Member

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    You could make a little video and email it to Freefly support, but they probably don't have an RT Motion to test with. Beyond taking a multi-meter and measuring the voltage out of the D-Tap, I don't have any electronic scopes that could tell you anything about the signal.

    But that's one thing you could check -- put a D-Tap splitter in line between the Movi and your RT receiver, and then you can measure the voltage with a multimeter as you turn the thumbwheel and see what happens.
     
  5. Danie kelly Brown

    Danie kelly Brown New Member

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    I am having the same problem with RT-motion and thumbwheel on movi pro. Strange thing is that it was working for awhile and then all of a sudden it started jumping around and like you said yours is doing. I was wondering if it was a recent firmware update that caused the problems, but reverted back two firmwares and still the same problem. I am thinking its some kind of voltage thing coming from the movipro power, because the thumbwheel and motor works when I power the rtmotion from a source other then the movi pro.
     
  6. Laura Garner

    Laura Garner New Member

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    I have the same problem. Thank you folks. Hope that these tips help me
     
  7. Chris Pettenaro

    Chris Pettenaro New Member

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    I power my LatitudeSK off of the DTAP on the top of my VLOCK I/O expander on the back of my Red Weapon.

    The other Dtap on the movi I use to power my Teradek Bolt 3000.

    Hope this helps, no issues with any sort of back and forth on my motors, even when on the Alta.

    Cheers!
     
  8. Robert Neilson

    Robert Neilson New Member

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    Going to resurrect this old thread and see if anyone as a fix for this? I have the same problem, and it seems to be voltages from the movi pro being a problem. If I connect the RT to an AB battery Dtap the jitters go away.

    I just attempted to split power from the CAM d-tap port since I'm only running a Komodo with a fairly low power draw for this shoot, and no dice...still jittered. Tried the Dtap port above the movi screen, and again no luck. I tried a Lemo to Dtap splitter from the Ignite Digi TB50 adapters and it seems to be ok right now, but was jittering when I had a low battery.

    Will hope to find a solution going forward.
     
    #8 Robert Neilson, May 5, 2021
    Last edited: May 6, 2021

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