rfcaddell Posted October 11, 2015 Report Share Posted October 11, 2015 Hey guys Just got my b-series mid vent a couple weeks ago and every time I fly it I'm hearing and seeing a flutter on the sail right wing bottom edge inside of the spar. I've tried tightening up the bungee cords at the top of this saill, but sound is still there. I've tried using more break but that doesn't help either, I don't have this problem with my other b-series std and full vent kites. Could this be a defect during the manufacturing of this kite? As always I appreciate all the information I get here (it's priceless) Ron Quote Link to comment Share on other sites More sharing options...
makatakam Posted October 11, 2015 Report Share Posted October 11, 2015 Try putting the top bungee back where it was and tighten the right side tip bungee. Sounds counter-intuitive, but it should help. You want to achieve equal tightness in symmetry, left to right. The bungees will not necessarily end up being of equal length. You're looking for equal tension, not bungee length. Also check the bridle legs for symmetry. Unequal flying lines can also cause more flutter on one side than the other. Measure the distance between the top and bottom handle knots on which you normally fly. If the difference between top and bottom is less than five inches add brake.Now that you are aware of it, you will probably notice that most of your Revs are not perfect. Fine tuning will correct the problem almost all the time. The components of the kite other than the frame will, over time, relax and stretch making adjustments necessary. If you try all of the above and still have the problem, get on the field with a more experienced flyer to determine what may be causing it. It is possible that the sail is not sewn properly, but it's not likely. 1 Quote Link to comment Share on other sites More sharing options...
rfcaddell Posted October 11, 2015 Author Report Share Posted October 11, 2015 Mark It never dawned on me to try the tip bungees, will give that a try and go from there. Thanks Ron Quote Link to comment Share on other sites More sharing options...
John Barresi Posted October 12, 2015 Report Share Posted October 12, 2015 If that doesn't cure it, please try to share some close up photos of the vented area and maybe video from right under the kite as it flies by (while making the noise). Quote Link to comment Share on other sites More sharing options...
hyzakite Posted October 12, 2015 Report Share Posted October 12, 2015 The buzz happens when the kite is over flying the wind. It happens when the wind flies the kite, not the pilot. It's like a Piper Cub trying to break the sound barrier, all hell breaks loose. It's all in your handles and your control, slow it down the buzz stops, give it drive and the buzz starts again. The rev is still a wing, like a bird, sailboat, jet airplane or race car wing. It's all the same, cheat the wind and they all will buzz. The back lines of the wing allows pressure changes on the wing. If you change the shape of a wing to mimic flat where you erase most of the pressure, the back of the wing will buzz. Just like blowing on a reed or a blade of grass between your 2 thumbs. Never mind! 1 Quote Link to comment Share on other sites More sharing options...
SHBKF Posted October 12, 2015 Report Share Posted October 12, 2015 When I first started flying Revs my kite buzzed quite a bit. I thought it was normal as it was a similar noise I've heard flying some dual line kites. Then reading the forum I ran across mention of the buzzing noise. So I tuned my handle leaders, changed my grip, slowed my flight a bit & the noise rarely occurred after that. Now it's something I do on demand like when I'm flying over a critter & want to get it's attention. SHBKF 1 Quote Link to comment Share on other sites More sharing options...
SparkieRob Posted October 12, 2015 Report Share Posted October 12, 2015 Overlay the 3 sails and see if there is an irregularity in the shape of the mid. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
oapbillf Posted October 12, 2015 Report Share Posted October 12, 2015 Several of my Revs suffered from this even at low forward drive, one full sail in particular was so bad that I very rarely took it out of the bag ! I cured this, after playing with bungees etc, by fitting leach lines between the bottom of the vertical rods and the centre vee ! That kite is now my "go to" full sail, most of the buzz has gone but it is still there a bit when driven hard ! If you want details of how I did this I will take some photos and write up a method ! Bill Quote Link to comment Share on other sites More sharing options...
makatakam Posted October 12, 2015 Report Share Posted October 12, 2015 Several of my Revs suffered from this even at low forward drive, one full sail in particular was so bad that I very rarely took it out of the bag ! I cured this, after playing with bungees etc, by fitting leach lines between the bottom of the vertical rods and the centre vee ! That kite is now my "go to" full sail, most of the buzz has gone but it is still there a bit when driven hard ! If you want details of how I did this I will take some photos and write up a method ! Bill I have installed removable small diameter (3/64") rods into the trailing edge pocket on one of my "modified" Revs. Quiet as a church mouse now. Quote Link to comment Share on other sites More sharing options...
Reef Runner Posted October 12, 2015 Report Share Posted October 12, 2015 I always thought that flutter and noise was usually due to "too little brake".............(all drive - no brake) On a noisy Rev, I always shortened the lower lines (by one knot on the leaders), and it seemed to cure the problem (?) (or) let out on the top lines But I don't know what happens if you have a "poorly sewn sail" ?? Best of luck, but try just a bit more brake, and see what happens - go nothing to lose, eh ! Quote Link to comment Share on other sites More sharing options...
John Barresi Posted October 14, 2015 Report Share Posted October 14, 2015 In just one instance, I came across a factory made B-Series full vent where the sail hadn't been laid flat enough when the venting was sewn on - this created ripples in the fabric around the vent panels and pulled things oddly so that no matter what we did... 1. Set good balance of brake / forward to minimize wind spillage. 2. Equalized bottom lines to ensure trailing edge control. 3. Flew in 10-14 mph, plenty to load up / inflate the sail. 4. Moderated flight speed (should silence any sail). After all that, the kite STILL fluttered and we traced it all back to the sail / vent sewing issue. The Rev platform is very forgiving to small construction errors at the end of the day, but unprovoked sail flutter is one thing I cannot abide by. Quote Link to comment Share on other sites More sharing options...
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