Cierva, a heart breaker from China ? - Page 3 - RC Groups
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Oct 16, 2010, 07:27 AM
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britinoz's Avatar
OK Gentlemen.
Today I have checked all my Autogyros for the various angles. On the Tractor models with the tailplane at 0 deg ,the rear tilt is between 4-6 DEG for level flight,and they all have 6 deg down thrust on the Motor.The Hang Angle is between 10-14 deg The Pusher models have a Hang Angle more like 18-22 deg.
I actually have a scratch built model of a C-30 just about the same size as the HK model and that flies OK with 6 DEG down thrust on the Motor.
Now GAZ tells us there is no down thrust on the Motor ,now that does not sound OK to me.Does that make sence to anyone???
I hope you can find that info Rich.
I am sure the Designer is watching this with great interest but I am also sure he will not show his hand,because if he does he will be bombarded with questions that are no longer his problem.
Happy Landings
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Oct 16, 2010, 08:30 AM
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Gaz-b's Avatar
I can see a down thrust angle now i look for it I was looking for a side thrust angle like on a fixed wing .well build finished last night to the pictures on HK site set the disc at 90o to the mast and it all looks very close to what is being sugested here I will go round it with a didital angle guage later and give it the beans tomoz weather looks to be suitable.
Oct 16, 2010, 08:50 AM
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Gaz-b's Avatar
Right then had a go round with the guage using the tail plane as 0o. disc is back at 8 o. down thrust 1.5 o. dangle 9 o. should I give it more down thrust or suck it n see.

Last edited by Gaz-b; Oct 16, 2010 at 12:17 PM.
Oct 16, 2010, 11:22 PM
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britinoz's Avatar
G'Day Gary.
That does sound a little better than your first report.BUT BUT,I think it can be a little better.As I said, I am flying a C-30 of the same size and it has 6 DEG down on the donk & 5-6 Deg back on the disc for level flight.You will find with an Autogyro that you never need to give down elevator,[just ease off the throttle a little] I think 8 deg back tilt is to much for a test flight.
You may find that the model will clime to fast out of your hand on launch,if so you would have to reduce throttle quickly.They can loop on take off.[I have done it more than once,and if your not ready for it SPLAT']
Also when using the hand launch [which is recommended for this size model] make sure the rotor is up to speed before release ,and only give enough power to let the model fly slowly out of the hand at just a little more than horizontal .It will not like a high powered 45 Deg launch
Also ,that hang Angle should be more like 10-16 deg.Autogyros run a lot more nose heavy than fixed wing models to save them should you have a dead stick.
They will dead stick OK as long as you don't pull to much back stick.[just like Heli's, it's a matter of getting used to the feel of the model.]
BTW Did you use MG BB servos on the head ,Because you will need them.Plastic gears strip REAL QUICK when blades strike the ground ,and believe me ,they will strike the ground.
Another thing you can do to stop gear damage is to only use the outer bolt on the blade mounting ,and use a balsa stick in the inner hole.This will hold the blade in position and allow it to move on impact sheering the stick & saving the gear.I use this on several of my models.
I have just checked my order and it has just cleared Customs in Melbourne,and should be on it's way to Adelaide over night.So hopefully I can give some advice soon.
Good Luck & happy Landings
Last edited by britinoz; Oct 16, 2010 at 11:29 PM.
Oct 17, 2010, 06:58 AM
Registered User
DHMIK500D's Avatar
G´Day Chris...

...I have read you using balsa shear pins.
Do you mean the wooden pins are to strong for this shear function?
Are the balsa pins strong enough to hold the blade during operation?

I have supported my leading and trailing edges and the wingtipp from my blades with strap tape.
Perhaps my blades are not so heavy destroyed after low speed damages (taxiing and start run)

I have the problem to have a small gap between the blade shim and the teeter surface in the wooden pin area (first hole) if the blades are not stressed.
If the blades rotate and the windforces working on the profil the gap is "disappear".

autogyro newbie
Oct 17, 2010, 08:53 PM
Registered User
britinoz's Avatar
G'Day Roberto
Now RE the Balsa pin in the inner bolt hole,It is only required to hod the blade in position prior to rotation because when the blades get up to speed they will stay in there correct setting by the weight of the blades.I always use long sticks ,so when they break ,it is just a matter of pushing the stick down and removing the broken piece.
They are made to break with light contact of the blade.
If you were to use a hard wood ,then there is a chance that they would not break,causing damage to the blades & servo gears.
Now you mention a small gap on the teeter surface.I think you will find this model does not have this feature [must be the LA 500] Sorry, I cant help you with this model.
Happy Landings
Oct 19, 2010, 04:51 AM
G'day gentlemen.
Did order and pay this beautiful autogyro from HobbyKing, even though its on backorder. I simply couldnt resist it!
I've never tried autogyros before, but have a fair share of experience from different planes and some on helicopter.
Have read the tips and experiences from here, and would like feedback on planned setup:
-HXT900 or Futaba S3114 servos?
-Towerpro 2409-12T
-Turnigy Plush 18A ESC
-Rhino 3S 1750mAh batteries

And very nice tip on the balsa pins Chris, especially since there are no spare rotor blades on HK. Maybe I need to order some from balsaplanes?

Crossing my fingers that the HK get new stock today! (yeah right....)
Oct 19, 2010, 09:38 PM
Registered User
Originally Posted by Texasredrider
Well guys, I received my kit today. Lots and lots of different pieces. Looks like pretty good quality. Only thing is, I received no instructions. Too many pieces to try to figure it out. Hopefully HK will post the manual so I can start the build, otherwise it will stay in the box...
I'm glad to know that someone else got the kit with no instructions. I have not found anything on Hobby King that looks like instructions. At least there are pictures on the HK site.
Oct 20, 2010, 01:50 AM
Now, what does this button do?
Nukiwi's Avatar
You will find a gentleman has posted some instructions on HobbyKing.

(Thank you, kind Sir!)
Oct 20, 2010, 02:48 AM
Registered User
britinoz's Avatar
This may be of some help to those of you having problems with this kit.
These are the settings that I have applied to my as of the moment unflown model.
The down thrust on the motor has to be adjusted to 6 deg .The down thrust on the front former is 1.5 down so packing must be applied to the motor mount.
The back tilt on the rotor head should be approx 6 deg for level flight ,this must be measured when the tailplane is at' 0' deg.I hope the pictures will help.
The other feature that every one seems to want to know is ,the CG.
With Autogyros it is refered to as the' hang angle',and to find it ,you have to hang the model by the Rotor spindle and measure the angle on the tailplane .It should be between 10-16 deg .The high end is better.
Unfortunately this model has been built VERY VERY HEAVY and I found that I had to use a considerably large Lipo than required to get the weight correct.For this size motor a 1250 MA pack will normally give a 10 min flight ,but I had to squeeze in a 2250 ma pak
The all up weight of the model with Lipo and Rotor came in at 775 gms which is about 250 gms overweight.
I hope to get to fly this model in the next couple of days ,and will advise of the result.
I am not over impressed with this model.
You may have noticed that my colour scheme is considerably different from all the other picture of the kit.Unfortunately when the kit arrived it was in a very sorry state,so rather than to go through the agro of sending it back ,and waiting for a replacement,it was quicker to rebuild the model and the blades.
It is not heavy because of the rebuild but because of the material used in the basic construction. In fact I believe I have saved some weight.
I am sure you will be aware to use the 'Delta wing 'setting on your TX for the head movement.
I am sure I have missed something,The old brains gone a bit wobbly. Don't forget to check the balance off the blades,mine were a bit out.[That is important]
happy Landings
Oct 21, 2010, 05:18 AM
Registered User
britinoz's Avatar

Spin Up

Today I took the machine out to see how the blades would spin up.
Standing with the model facing into a good breeze with the model held at 45 DEG the blades did spin up easy, BUT there was no drag [pull] on the arm as you would expect ,and when the model was moved into the horizontal position with power applied ,it was as if the model got heavy.It felt as if I was trying to launch a fixed wing model ,with no wing.The blades are 442 x 40 x 5 mm with a 4 deg wedge at the root. I have never used blades this thin before . I also noticed that they did not appear to be any conning ore droop from the blades. Very strange .When I disassembled the plate, I found that the flexing plastic plate had very little flex. I have made a new plate with more flex and if that does not work ,then I will make a new set of blades.
Oct 23, 2010, 04:30 AM
Registered User
britinoz's Avatar

New Blades

I have spent some time playing with a more flexy plate and the H KING blades ,but unfortunately they still do not appear to generate any lift. It looks as if they have started with 5 mm wood ,and sanded away.I think that 4.74 mm may be to thin to generate lift,
SO then I made a new thicker set ,and hopefully they will work.
The problem that I have is that this model will generate interest from modellers that have not had previous experience with Autogyros ,and will not know the features to look for, and will just try to fly ,possibly with out any luck.
If I am having problems ,considering that I have a reasonable understanding and ability to fly,then what chance will a novice have?? It's a great shame.
I will advise on my findings.
Not Happy
Chris ??????????????
Oct 23, 2010, 11:42 AM
Registered User
microraver's Avatar
i received my kit a few days ago. i've been trying to find as much info on the build of this since this will be my first autogyro. thanks britinoz for your posts. but i have to admit i'm not even past getting it out of the wrapping. i hope to have the build started at least by the weekend.

i am going to use the photos from HK and from this thread as well as this informative build post from Jeff Waters:

as for the more advanced setups i will be looking at the suggestions from Britinoz. can't wait to hear about the maiden mate!
Oct 23, 2010, 12:51 PM
Registered User
hokonghing's Avatar
my first Autogyro too, just want to do something different, Britinoz, please keep the advise come in, I am following your foot steps.
Oct 23, 2010, 09:02 PM
Mines faster than your's
Texasredrider's Avatar
Looks like this may turn into an expensive static model, eh? HK said its easy to fly. Handles like a Cub!

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