Welcome to PhantomPilots.com

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

GEMFAN CF 9 X 5 props

Discussion in 'General Discussion' started by yappy, Apr 19, 2013.

  1. yappy

    Joined:
    Apr 3, 2013
    Messages:
    36
    Likes Received:
    0
    Has anyone used these or have experience with them? They are carbon fiber props.

    I just got them delivered to me, but have not tried them yet. I'm still using the plastic props that came with the phantom.


    Has anyone had any problems with these props ? :?:
     
  2. MX45OR

    Joined:
    Feb 18, 2013
    Messages:
    161
    Likes Received:
    0
    Yes, and i like them. they are a little fragile though. I have broken 2 of them, one with a power line hit while in fpv (didnt see the lines) and the other broke when I tried to land on a roof and the Phantom didnt like the angle and tried to correct itself.
    Although they are stiff and climbing is a breeze, they do produce a lot more noise. I bought another set, but i put on the black DJI props. oh yeah, get yourself a .3125" (5/16") reamer to open up the hole, for ease of installation. The first set was a little thin where the nut goes on, I had to add a .0625" washer to tighten the nut down, and keep the props from spinning on the motor shaft.
     
  3. lilwheat

    Joined:
    May 13, 2013
    Messages:
    94
    Likes Received:
    0
    Sorry to reply to an old post, but..

    I had my phantom 'fly-away' from me this weekend.. naturally 2 days before my Gemfan 9x5 carbon fiber props showed up.. so it may be some time before I get to try them, but I had a question.

    I ordered these from RC-Drones.com and they're advertised as being a direct fit for the DJI Phantom, but the hole is not 'keyed' the same as the motor shaft of the phantom. Is there an adapter or a different type of nut that should be used?

    Also, I paid the extra money to have them balanced and upon receipt, each prop has a blade with several pieces of scotch tape on them. Is this the proper way to balance a carbon fiber blade? Looked a little off to me.

    Thanks in advance for any feedback and happy flying!
     
  4. freelanceshots

    Joined:
    Apr 21, 2013
    Messages:
    187
    Likes Received:
    3
    Location:
    Dallas, Texas
    Tape is the best way that I've found to balance props. You can always pull the tape off and re-balance if you need if things get out of whack. My first props I sanded like in some of the youtube vids where I won't do that again. I had to remove a lot of material to balance and then that can change the shape of the prop or surface or send balance out even more. On all my plastic props the horizontal balance wasn't way off compared to the vertical balance or at the hub. Would be nice to get a perfectly balanced prop out of the package just because they were made like that.
     
    Tricky likes this.
  5. Gizmo3000

    Joined:
    Jan 25, 2013
    Messages:
    1,859
    Likes Received:
    2
    Location:
    Sherman Oaks, CA
    tape is the most practical, yet least elegant way to balance a prop.

    a more aesthetic, and more permanent method is to use AC glue to add weight to a prop, which also works for balancing the hub.

    AC glue can also be sued to create and the file a keyhole so that the aftermarket non-keyhole props won't spin freely.
     
  6. tanasit

    Joined:
    Jan 28, 2013
    Messages:
    554
    Likes Received:
    2
    Been there done that with all kinds of tape, heat shrink tube, sticker sheet as well as the air plane covering sheet and helicopter wood blade covering sheet. Paint either brush on or spray on. Sanding or even carving (shaving) with utility blades. And finally the CA which I only use to balance the hub. With larger wood blades, sometime I had to drill (not through and through) holes and fill them with lead shots. Many pre-balanced helicopter blades have the lead wire glues inside the groove near the leading edge by the tip to promote the forward CG required.

    I was not happy with the thick tapes like electrical tape and was not happy with the tapes that wouldn't stick well or start to peel off in the heat of the sun.

    With cheap plastic props that I tried on the Phantom, I used both brush on and spray on paint. Note that the brush on which is thicker than the spray on will only go on the "bottom" of the blades. For best result, you must lightly sand the blades first. The disadvantage of using the paint is that you have to wait until the paint is totally dry and check the balance again. But if you have been doing this long enough, you will learn how much over paint you will need so that once dry the balance will be on the spot.

    Removing material from the prop too much will definitely compromise the structural integrity thus not recommend for the "thin" electric props. However with the stock Phantom prop and those carbon fiber ones, I found that the balance is very close to perfect so I chose to sand the underneath near the hub.

    It won't hurt to re-balance the props every now and then and you will be surprised why some of your well balanced props are not perfect any more. ;)