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Lens Filter Counterweight Mod for DJI Phantom 3 Std

Discussion in 'Standard/4k Discussion' started by OrlyP, Mar 19, 2016.

  1. OrlyP

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    Just sharing what I did to overcome the weight imbalance after installing a 3rd-party lens filter kit.

    CAUTION: This mod is provided to you in good faith. You will be solely responsible for any damage that may incur as a result of applying this mod.

    I recently bought a generic lens filter kit online. The fitment was perfect except that the weight of the lens adapter, including the actual lens, seems to be too much for the gimbal pitch motor to handle. During flight, the pitch motor would seem to overload, go limp then restart. It would happen again every few seconds and it is quite apparent that the camera is unusable in this state.

    I immediately thought of using lead weights that were meant to be attached to rims to balance car tires. The weight strip I got has a total of 90 grams and marked with 5g and 10g graduations. I velcroed a 10g piece behind the camera and a 5g piece on the other side of the roll arm. I made sure that the lead weight clears the ribbon cable behind it.

    Results:
    The Good: Gimbal is performing wonderfully. It cured the pitch motor overloading.
    The Bad: The solution adds 15g to the gimbal and camera assembly, which is really not that much. That said, every gram added to a hanging structure is amplified during hard landings or crashes. My solution is to hand-catch the aircraft every chance I have.

    Moving forward, it seems that the velcro is too puffy, putting the lead weight dangerously close to the ribbon cable. I might change it to a double-sided tape to increase clearance.

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  2. mdowney58

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    Of all the threads I've read regarding filters, this is the first time I've seen anyone discuss adding counter weights to the gimbal.
    And if you added 15g counter weight, it sounds to me like a total weight gain to the bird/gimbal of 30g.
    I wonder if 30g added to the gimbal is good for it.
    Makes me wonder if the kit you purchased is not the best choice.

    Sent from my SM-N910V using Tapatalk
     
  3. OrlyP

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    It's still experimental. I intend to further reduce the counterweights to a minimum, or to zero.

    I've read feedback of others using the same kit that only the CPol filter is heavy. The ND filters seems to be light enough not to require any weights at all. I haven't tried it as I initially thought the weight wouldn't matter much between the CPol and ND.
     
  4. ghook73

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    Exact same problem. Adapter is 3 grams. UV/NDs 5g each. CPol 9g. No problem if no more than 8g total. Any combo with the CPol will cause the gimbal drop out. Two quarters for counterweights at 6 grams each will work for all combinations and keep total weight down. DJI tech support recommended no more than 8 gram for filter/adapter although they said there was no printed limit. Curious how hot your gimbals feel after a 20 minute flight with your counterbalance solution. A noticeable difference with and without?


    Sent from my iPhone using PhantomPilots mobile app
     
  5. MILLER4PRESIDENT2020

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    I just through my filter on and never thought twice about it any everything seems fine. What led you to the conclusion that you need counterweights?
     
  6. mdowney58

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    The OP said his gimbal started overloading and going limp once he installed the filter

    Sent from my SM-N910V using Tapatalk
     
  7. OrlyP

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    I wasn't exactly taking note of the gimbal temperature. Though, touching the camera to extract the memory card immediately after landing and it didn't felt warm at all. I don't think it could be worse than when I didn't have the counterweights on. Besides, the prop wash do help in keeping the gimbal cool during flight. The gimbal tends to become hot only when powered up with the prop motors turned off.
     
    #7 OrlyP, Mar 21, 2016
    Last edited: Mar 21, 2016
  8. OrlyP

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    That's correct. With the adapter sleeve and the CPL filter installed, the camera at first would settle facing forward after initialization, as it normally does. But the tiniest bump or a relatively fast ascent would cause the camera to pitch down and dangle (front-heavy). It would dangle for a couple of seconds before the pitch motor would re-initialize. A few moments later, the same would happen and cycle goes on and on.

    Other people who also bought the same kit claims that only the CPL was heavy, and that using either the UV, ND4 or ND8 filters didn't cause any issues with the gimbal pitch motor. I have yet to try that.
     
  9. CRF319

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    I have a similar kit I recently bought off of Amazon.
    I've only had one flight since the kit arrived and I used the CPL filter, during the flight and watching the video I did not notice any odd gimbal movements.
    My adapter and CPL is 9.5 g and the 4 or 8 ND with adapter is 7.5 g.
    I will monitor my flights when I use the filters and report back if I have any erratic gimbal movements.
     
  10. finalfantasyfan

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    Instead of counter weight, have you thought about cutting the filter adapter shallower to reduce the weight?
     
  11. OrlyP

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    I have considered it but I preferred a less destructive approach.

    With about 3+ more flying hours with the mod, I think it's going to stay for now.

    This is problem I had without the counterweights:

     
  12. finalfantasyfan

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    I have similar kit made by Neewer. The Adapter is 3g, ND are 5g and CPL is 6g. I don't have problem like yours. Maybe your CPL is too heavy.