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Why does the HK SuperG autogyro needs the rotor head tilt to the left?

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Why does the HK SuperG autogyro needs the rotor head tilt to the left?

Old 06-02-2015, 01:40 AM
  #1  
gadily
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Default Why does the HK SuperG autogyro needs the rotor head tilt to the left?

Hi all,
Looking at the HK SuperG autogyro manual I found "critical note" that says that rotor head must be tilted 7 deg to the left.
Also I found in the manual trouble shooting section that if the model rolls to the right is due to the rotor head not pre angled to the left
I have flown few times my HK 2 Auto G2 gyrocopter.
At take-off phase the model rolls sharply to the left without exception.
The rotor angular bias was zero deg. (Please see attached photos and video clip)
https://www.youtube.com/watch?t=43&v=OM79DZ463c4
According to my aerodynamic understanding the SuperG gyrocopter should roll to the left after take-off.
Both models have CCW rotor angular movement.
The advancing blade on the right side "sees" both airspeed
And linear speed while the retreating blade on the left side "sees" the difference of airspeed and linear speed.
This difference between the blades "produces" roll moment to the left.
May one of you please explain me why the SuperG manual requires that rotor head must be tilted 7 deg to the left
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Old 06-02-2015, 03:13 AM
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flyinwalenda
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Probably because one is a tractor and the other a pusher prop configuration and the pusher may not have any set thrust angle on the motor like the tractor set-up does.
Old 06-02-2015, 04:58 PM
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XCaliber
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RC model Geeks recently maiden his super G, and after landing he states and shows how much of right trim he need almost level.
https://youtu.be/tCBzEgDg_PI
The 7deg. left trim in the manual is extreme and I am not going to follow it. I have set my to 1-2deg of right trim for my maiden like my AC-10.
Old 06-03-2015, 06:13 AM
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gadily
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Hi flyinwalenda - I dont think it has to do with tractor or pusher props.- Both the AG2 and the Super G props turn clockwise and has zero right thrust.
Hi Xcaliber - Wish you success in your maiden of the AC-10.
Have you flown other auto gyros in the past?
Old 06-03-2015, 07:36 AM
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XCaliber
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Hello gadily,
Yes, I have flown many. The G/G2, HK Cierva 30, 60 size Cierva 30, 60 size Pitcairn. Yes, I have maiden the AC-10 successfully.
The Super G should be like flying a Piper Cub.
Old 06-03-2015, 09:28 AM
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gadily
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Hello Xcaliber,

Can you give some details about AC-10?

Did you have problems (like mine with AG2) with strong roll to the left after take-off with any of your auto gyros?
Old 06-03-2015, 03:11 PM
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XCaliber
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Yes, all of them rolled left after takeoff, specially when the rotor is not to speed. I found that a 1 to 2 degs right tilt is about correct to start off.
The AC-10 rolled left on take off also with the left tilt recommended and I needed all the right trim my radio could give for level flight.
Old 06-03-2015, 09:33 PM
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gadily
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Did you consider using flight stabilizer in your auto gyro?
Old 06-04-2015, 08:08 AM
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XCaliber
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Gadily, I think I made a rely on a you tube video of your G2 a while back. We exchanged a couple of replies, and I mentioned that I use a 3-axis flight stabilizer on most of my auto gyros.
I don't have one on the super G at this time as I don't think I will need it, but will see.
Old 06-09-2015, 06:09 PM
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XCaliber
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I only needed about 2.5deg. left tilt after maiden flight on the Super G. No need of flight stabilization!
https://youtu.be/GYkuC1NE0zM
https://youtu.be/BdE4TrvpT_4
Old 06-10-2015, 10:06 PM
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gadily
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Hi BRNVIPER, Very nice video. I looks like you had small right roll after take-off.The 2.5 left tilt is really needed. Do the Aerobalsa custom blade need any modification in order to be installed on the Super G rotor head?
Would like to see a photo of the Aerobalsa blades on the Super G rotor head.


Gadi

Old 06-11-2015, 07:11 AM
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XCaliber
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Hi Gadi,
Thanks, yes I did need 2.5 to 3degs left tilt for level flight. I used a pack of three 2 3/8" x 36" Aerobalsa blades from FlyingBalsa.
Cut them to 21", carved the root 30mm wide, bolt hole is 15mm from leading edge with a brass tube. 37grams all 3, no weight at the tip. C.G of all 3 at about 230mm from root. I Cover them with Coverrite.
I noticed these blades have more lift than stock as I needed down elevator trim with the 3000mah battery. I will try with 3500-4000mah.
Forgot to mention, I glued 1/64" aircraft plywood on the upper and bottom of root.
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Last edited by XCaliber; 06-11-2015 at 07:24 AM. Reason: forgot to add info.
Old 06-11-2015, 09:31 AM
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gadily
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Thank a lot Xcaliber for the clear photos.
By the way did you try to use the original blades before using the Aerobalsa blades?
Gadi
Old 06-11-2015, 10:24 AM
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XCaliber
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Yes I did, but I like the Aerobalsa blades better.
Here is a short video of one circuit with the stock blades.
https://youtu.be/zBGXE_4Xyx8
Old 06-17-2015, 10:29 AM
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airbusdrvr
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XCalibre, I'm ordering a set of blades from Flying balsa and intend to build a set as you did. I noticed you used 2.5 to 3 degree left tilt. Where is your CG? Also noticed it appears you are not using the prop spinner supplied and maybe a prop adapter as the prop looks closer to the motor. Any other thoughts on your setup would be appreciated.
Old 06-17-2015, 05:26 PM
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XCaliber
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airbusdrvr, the C.G. with the 3000mah 4cell pack is at about 420mm from the nose back. The manual recommends 415mm. I had to give about 1/4" down elevator for level flight. On my next outing I am going to try a 4000mah 4cell pack with the C.G at 400mm.
I am not using an adaptor for my 9x7.5 prop. It must be closer because I'm not using the spinner so no spinner back plate.
Old 06-25-2015, 05:59 PM
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XCaliber
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Had a chance to try it out with a 4000mah 4cell pack and the C.G was spot on, didn't need much down trim.
As of now, this set up has been the best for me. Case closed!
https://youtu.be/ibsyLrCOsWE
Old 06-26-2015, 02:10 PM
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airbusdrvr
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What is the weight of your 4000mah batt? As per HK recommendation, I bought a 2800mah battery. Just curious how much weight I might need to add to use the 2800 batt. My Flying Balsa blades are finished but not covered. I hope these solve the shaking issue when spinning up the stock blades. Also, plan to reduce rotor tilt to 3 degrees left.
Old 06-26-2015, 04:20 PM
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XCaliber
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The weight on the batt is 417gr.
https://youtu.be/FvUO7vTzQ0E
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Old 06-26-2015, 10:08 PM
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gadily
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Hi Xcaliber,
Very nice video. It looks like you fly the Super-G like a trainer (or Piper Cub)
Since my flying field is relatively short and most of the time you need to make right hand circuits I would like to ask you how are right hand circuits relatively to left hand ones?
I looked again at your videos and saw that most of them are made left hand circuits.
Maybe you could try a right hand circuit in your next flight?
Gadi
Old 06-26-2015, 10:15 PM
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gadily
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Hi airbusdrvr,
Have success in your maiden flight.
Wish to see you flight video.


Gadi
Old 06-27-2015, 06:39 AM
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XCaliber
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Thanks Gadi, yes next time I am going to do right turns now that it's all dialed in.
It's always more critical to do right turns on auto gyros with counter clockwise blade rotation.
But the Super G will do just fine.
Old 06-29-2015, 07:04 AM
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airbusdrvr
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Not sure what's going on here attempting to upload pic files from my phone. Maidened my SuperG this AM. Used three degree left tilt for rotor and needed no aileron trim in flight. Added 5oz of weight to my 2800mah batt install and still needed a good bit of down trim. My FlyingBalsa blades all came out within 0.1 gram ([email protected] and [email protected]). I plan to replace the chincy (sp) wheel axles and strengthen the soft aluminum landing gear. Bottom line, it flies. Oh, my SuperG turns equally as well left or right.
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Old 06-29-2015, 07:08 AM
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airbusdrvr
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More pics?
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Old 06-29-2015, 11:49 AM
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XCaliber
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airbusdrvr, congrats on your maiden.
Glad to know that it turns both ways equally and will try it next time out.
Your blades look good also.

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