Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Professional Cannot balance DJI Carbon reinforced propellers

Discussion in 'Phantom 3 Help' started by Dronason, Dec 5, 2015.

  1. Dronason

    Joined:
    Aug 9, 2015
    Messages:
    498
    Likes Received:
    82
    Location:
    Switzerland
    I purchased 2 full sets of DJI Carbon reinforced props.

    I have a Dubro prop balance that I use to balance plastic props with success. I use sandpaper for the blades and the hub. The amount of material seems reasonable and the props works fine that way.

    I purchased carbon reinforced props directly from DJI store, so I assume they are not cheap fake replica.
    I have no problem to balance the blades the same way as for normal props.
    For balancing the hub, I go nowhere, it is fare from balanced. I tried sandpaper, the plastic tape, then aluminium tape. None bring me to a point I would be close to balance.

    Before going for really machining the hub and removing significant amount of material, I prefer to ask for advise.

    In flight is not that bad, but at power up (low rpm of props) the bird is shaking like I would expect for badly balanced props.

    All my 8 carbon props behave the same and the tool for balancing props work fine with normal props.

    Any advise or similar experience?
     
  2. bobmyers

    Joined:
    May 10, 2015
    Messages:
    3,611
    Likes Received:
    866
    Location:
    San Antonio, TX
    Use thin CA on the hubs -- a drop at a time.
     
  3. Dronason

    Joined:
    Aug 9, 2015
    Messages:
    498
    Likes Received:
    82
    Location:
    Switzerland
    Thanks, will try.
     
  4. Dronason

    Joined:
    Aug 9, 2015
    Messages:
    498
    Likes Received:
    82
    Location:
    Switzerland
    Has anybody tried to balance such props?
    Were they unbalanced as normal props?
     
  5. grasberry

    Joined:
    Sep 19, 2015
    Messages:
    2
    Likes Received:
    1
    I balance the DJI carbon fiber props with the Dubro balancer and 200 grit sandpaper to remove material along the entire length from the underside of the heavy prop end. Remove small amounts of material, recheck for balance, remove a little more material and recheck for balance until a balanced condition is indicated. Then polish the sanded area of the props underside with a few strokes of 400 and then a few more strokes with 800 grit. Of course, take care not to remove too much material with the 200 grit as the polishing sequence to follow may result in you overshooting the balance point. You'll get a feel for it after you have balanced one or two props.

    I've used the 200/400/800 grit balancing sequence successfully on all of my carbon fiber props since day one, while 400/800 works fine on the white plastic props. I've found that the DJI props are closer to a balanced condition than the aftermarket props I tried so I would recommend staying with DJI produced props. I will not install an unbalanced prop on my p3a. Unbalanced props can cause a host of problems from control to chassis stress cracks. Yes, stress cracks commonly found on the chassis arm are most likely caused by out of balanced props.

    Finally, if you cannot balance a prop using the aforementioned processes, or if you have to remove too much material to attain a balanced condition, break the prop and toss it in the trash. Why break it? Because some idiot will dig it out of the trash and put their new "free prop" on their bird and possibly injuring their phantom and/or their self.
     
    AlexSP likes this.
  6. AlexSP

    Joined:
    Oct 30, 2015
    Messages:
    295
    Likes Received:
    237
    Same here. My DJI CF reinforced props are balanced that same way and it's ok. I don't bother balancing the hubs that much because it's very much within acceptable tolerances in perhaps 99% of DJI props and far from causing any issues. I too only use DJI props.
     
    Solar Deity likes this.
  7. Dronason

    Joined:
    Aug 9, 2015
    Messages:
    498
    Likes Received:
    82
    Location:
    Switzerland
    Sorry to answer late but I was on a business trip.
    Thanks all for the answers, strange than mine are so much unbalanced.
    I will recheck the way I balance them.