Register

If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Results 1 to 16 of 16

  1. #1

    Join Date
    Sep 2005
    Location
    SingaporeSingapore, SINGAPORE
    Posts
    132
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    Noisy Hitec Servo on Flaps of Futura

    Hi all,

    Need some advice.

    I was fixing the flap servos on my Futura 1.9m tonight. I am using a Hitec HS 7985MG on 6V.

    When i powered up the servo, there was a lot of loud buzzing and clicking. The clicking is accompanied by vibrations on the control surface.

    The same phenomenon is observed when I switched the servo to a HS7955TG. I also tried increasing the dead band width of the servos (up to 4). Although the clicking noise is reduced (it did not go away), I noticed the servo "over-travels" at this setting.

    The servos were connected to a Futaba R6014HS RX for the tests.

    In the video, the servo is the 7955TG. There is a bit of binding when the flap is fully up but none whatsoever when the flap is deployed.

    Is the chatter normal for Hitec servos... I am not so worried about the noise the servos are producing but it is the vibration that is making me uncomfortable.

    Would appreciate any advice.

    Thanks.

    Isaac

    http://www.youtube.com/watch?v=P36Z8...ature=youtu.be

    [youtube]http://www.youtube.com/watch?v=P36Z8sEVXYw&feature=youtu.be[/youtube]

  2. #2

    Join Date
    Mar 2009
    Location
    East Yorkshire, UNITED KINGDOM
    Posts
    156
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    Ive used the 7955TG all round on my Flash and they have a similar buzzing noise on each of the surfaces, especially the Flaps and Ailerons as they are having to hold the weight of quite a large surface, it sounds like there is maybe a small amount of binding when the Flap is in the Up position, I would maybe check this with an In Line amperage meter to ensure the correct amount of Current Draw in the different positions. Ive never noticed any vibrating of the surfaces on our models though, only ever on a customers CARF Eurosport (with Hangar 9 3D style Control Arms causing the Servo to try and over center) but this was cured by an adjustment of the dead band width and he was advised to make sure the setting was good for him before flying the model.

    If its the slight buzzing your concerned about, other than in the Up position, I wouldnt worry, Ive had over 100 flights on my flights on my Flash and its worked flawlessly but I would maybe just check for any unwanted binding.

    Hope this helps.

  3. #3

    Join Date
    Dec 2001
    Location
    mia, FL
    Posts
    2,249
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    Sounds normal to me
    It's a hobby - keep it simple

    www.332ndredtail.com

  4. #4

    Join Date
    Sep 2005
    Location
    SingaporeSingapore, SINGAPORE
    Posts
    132
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    Hi all,

    Thanks for the advise... The vibrations that i mentioned in my post are actually jitters.

    Found a better word while searching for a solution online.

    It jitters and clicks (not continuous hum) at takeoff and landing flap positions.

    Not sure if it would quiet down once under constant Loading while flying. I think I will set the deadband to 3 and re-test.

    Isaac

  5. #5
    Meesh's Avatar
    Join Date
    Jan 2003
    Location
    Dracut, MA
    Posts
    2,728
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    I'm assuming the plane is being worked on and your transmitter is very close to the plane.

    Try backing away a little and see if the jitter subsides.
    If it\'\'s worth doing, it\'\'s worth doing it right.
    AMA 779352, JPO 1965, IMAA 40337

  6. #6

    Join Date
    Dec 2001
    Location
    Plymouth, MI
    Posts
    2,480
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    That's why I don't use digital servos on flaps. Digitalsalways hunt for center and the weight of the flap and/or slight binding in the up position will make them buzz and vibrate. Replace them with a set of HS645MG's (or comparable analogs) and your problems will go away.

    Joe

  7. #7
    Meesh's Avatar
    Join Date
    Jan 2003
    Location
    Dracut, MA
    Posts
    2,728
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    I'm with Joe. Hitec 645MG on all flaps.
    If it\'\'s worth doing, it\'\'s worth doing it right.
    AMA 779352, JPO 1965, IMAA 40337

  8. #8
    k12rc's Avatar
    Join Date
    Feb 2007
    Location
    reidsville, NC
    Posts
    750
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    ±1 always use. Anlog on flaps
    ORIGINAL: Meesh

    I'm with Joe. Hitec 645MG on all flaps.
    don\'\'\'\'\'\'\'\'\'\'\'\'\'\'cry\'\'\'\'\'\'\'\' till\'\'\'\'\'\'\'\'it hits

  9. #9

    Join Date
    Sep 2005
    Location
    SingaporeSingapore, SINGAPORE
    Posts
    132
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    Hi all,

    Thanks for the replies.

    Yes, my tx was placed within a metre of the rx when I did those test. Will try moving it further and re-test.

    Also found another possible solution online which was to damp the control horn movement by sandwiching a piece of Velcro (soft side) between the servo casing and the servo horn. Will also try that and feedback should someone else be interested.

    If all attempts fail... I will replace with an analogue servo as recommended. Just want to try to resolve the digital "clicking" as I might face the same issue if I mount them elsewhere.

    Isaac

  10. #10
    Nhalyn's Avatar
    Join Date
    Oct 2010
    Location
    Paris, FRANCE
    Posts
    377

    RE: Noisy Hitec Servo on Flaps of Futura

    A thing you have to think of, if your Futura is your fisrt full composite bird (don't know for th emoment), is that this wing is a real resonator chamber !

    The same servo (7955TG) on the same wing but constituted of plain foam + obeshi would produce less noise or un-noticeable noise...

    Looking at your video, the "noise" seems also normal to me. I use this servo on the flaps of a propelled plane and all work flawlessly for 3 years now... I use also the same servo on the horizontal (full moving) stabilizer of a 1/3 scale Ka6E gliser, and it work flawlessly since first flights a year ago.
    "You've never been lost until you've been lost at mach 3 !" (a test pilot of the SR-71)

  11. #11

    Join Date
    Sep 2005
    Location
    SingaporeSingapore, SINGAPORE
    Posts
    132
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    Hi,

    Yes I think you were right about sounds being amplified by the futura wing... I encountered the same in another plane that I assembled sometime back... It is the jitters that i am encountering in the current setup that had me concerned.

    I did the tx position and Velcro trick... The Velcro does help to some extent but I am going to change out the servo with a 645mg that I have in my box spares. Will save the digital servo for other applications.

    I have a video of the result of applying the Velcro which I would post later when I get on a PC.

    Thanks again for the suggestions.

    Isaac

  12. #12

    Join Date
    Sep 2005
    Location
    SingaporeSingapore, SINGAPORE
    Posts
    132
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    The video of my velcro test. I don't encounter jitters and clicking when the flap is deployed anymore but when I raise the flap, it comes back.

    The photo shows the placement of the velcro.

    [youtube]http://www.youtube.com/watch?v=s7tIBbdygRY[/youtube]
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Yw68206.jpg 
Views:	27 
Size:	70.4 KB 
ID:	1810219  

  13. #13
    jetpilot's Avatar
    Join Date
    Dec 2001
    Location
    Allen, TX
    Posts
    2,723
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    I always use digitals on flaps. Usually 8711's.
    I try not to have a metal arm on a metal clevis.
    Scott
    Scott Marr

  14. #14

    Join Date
    Sep 2005
    Location
    SingaporeSingapore, SINGAPORE
    Posts
    132
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    Hi Scott,

    Thanks for voicing out the concern with regards to metal clevis to metal horn contacts. It shouldn't be a problem for mine as my clevises are kept tight on the horn with the use of washers as spacers to prevent slack and therefore excessive rubbing.

    I am actually more worried about plastic servo horns not up to the task and stripping its spines during flight as several people had encountered in this forum.

    Isaac

  15. #15
    Ali's Avatar
    Join Date
    Apr 2002
    Location
    Northamptonshire , UNITED KINGDOM
    Posts
    4,893
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    First video looks fine and sounds fine to me. Not sure I am too keen on the Velcro idea as this is Putting a constant load onto the servo through friction. Domt forget as soon as you are doing 1mph upwards there will be some form of load on that surface anyway. Adding more to me seems like a great way of burning a servo. I know the Velcro trick from the aerobatic guys who put it on surfaces to stop a servo that fails to centre each time, but in this application I see it as more of a hindrance than a help.
    Relax and go fly.
    I am with Scott on the plastic arms. If the correct ones are used then I actually prefer them over metal.
    Regards Al
    Al's Hobbies, Horizon Hobby, Airworld, BVM, Jet Cat, Skymaster, FEJ, Rc Jet Centre,pull over, Tomahawk, C-ARF, Jet-Teng,Kingtech

  16. #16

    Join Date
    Sep 2005
    Location
    SingaporeSingapore, SINGAPORE
    Posts
    132
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Noisy Hitec Servo on Flaps of Futura

    Hi Ali,

    Thanks for the advice and reassurance.

    Isaac


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT -6. The time now is 06:51 PM.

SEO by vBSEO 3.6.1 ©2011, Crawlability, Inc.