ciervapilot

Hi!
I built the Tango autogyro this summer. The maiden flight was not satisfying, because it crashed.
The flat paddle rotors are very ineffective. Now I've built three blade rotors with Clark y airfoil and increased the nose down angle. Hope it will fly.
Has anyone made such experience, perhaps with similar models?

floridagyro

Hi,

The flat rotor blades don't add much lift, however they do add a lot of stability. If you put lifting rotor blades, like clark Y or the SG6042 profile you may have more problems. For some reason, the air over the wing will cause one or both rotors to stop spinning. If they both stop that is OK, however one usually stops before the other and the gyro will roll over. If you want to use lifting blades, you need to eliminate the wing. Build some booms to hold the rotors from 1/2" square hard balsa. I've built many and they work well.

What kind of problem did you have that caused the crash because the Tango usually flies well as designed.

Phil

floridagyro

Hi,

Here is a link to a video, about 1.9 meg size, of a dual rotor landing which is about the same size as the Tango. This has the lifting blades and the booms made from 1/2" hard balsa.

Just click on the picture on this page to see the video.

http://www.auav.net/autogyro/dualrotorlanding.html

Phil

ciervapilot

Hi Phil!
I don' t know the reason why it crashed.
When I started, the model was very sluggish on the rudder. I hardly could make a turn. Straight on, it flew about 300 feet and at the next turn, it lost hight and crashed nose down into the ground.
First, I thought of a wrong CG, but it was OK.
Wind conditions were good, and I started right into the wind.
Well, I read the improvements for the Gyrace at http://www.autogyro.com/models/grceinfo.htm and there Jim wrote to use Clark Y airfoil blades.
So I don' t know what to do: build again new flat paddle blades or try to fly with the airfoil shaped ones.

floridagyro

Hi,
With the non-lifting blades the small wing on the tango provides the lift so it has to fly pretty fast to stay in the air. I suspect the Tango could also use a larger rudder but it sounds like it's just flying too slow.

If I were to rebuild, I would go with the lifting rotor blades and discard the wing. It flies much slower and handles like a gyro.

Set the booms coming from the top of the fuse to about 12 degrees up. Tip the rotor shafts out about 4 degrees and that will allow more clearance for the rotor blades over the booms. Mount the blades flat and do NOT tip them up as shown for the updated tango. Make the hubs solid so they don't flex. I also recommend the SG6042 profile blade as it provides more lift then the Clark Y. Have the tip of the blades swing even with the side of the fuse.

If you can, increase the size of the rudder it will provide more control. By keeping the rotor blades close to the fuse helps the rudder control.

Set a positive pitch on the rotor shafts of about 12 degrees, relative to the thrust angle and you should should have about 4 degrees of down thrust on the engine.

If you need more information please let me know.

Good Luck,
Phil

floridagyro

Hi,

Me again, if you want you can use the wing, but raise the rotor blades to 5 or 6" above the wing. This should eliminate the rotor stalling problem.

Do some testing by hand holding the gyro in the wind and watch the blades. If they spin up good, you should be OK.

Use a solid hub, no flexing, 12 degree pitch on the rotor shafts. Also, add a couple more degrees of down thrust on the engine to compensate for the height of the rotor blades.

Because you will have a lot more lift, be ready with down elevator as it may want to loop with you on take off, depending on how much power that you have.

Good luck,

Phil

MID-AIR

My Feedback: (10)

this is not a reply, just wanted to start a new post i just got bacl to gyros after 3 yrs absence i built a gyrace cause they fly so easy. 3years ago i built a dc gyro and it was trimed and flown at martinsville by one of the top flyers there, when i got back home i tried to fly itmy self, got it in the air with no problem but when i went to turn it to the left to avoid the trees it had a delayed responce so i gave it more input ,it turned but to fast so i contered with right again a delay more input ,it went into the ground. that ended my single rotor flying. now i want to get back to it , but need to know if all dc types have such a delated responce, my twin rotor gyrace dosent , instant responce! was it me or?

floridagyro

Hi,
The forward speed determines how fast the gyro turns when tillting the head. If flying slow or almost hovering the rudder will have more affect than tillting the head. Learning to use rudder is very important with gyros.

Do you know how many degrees of tilt that you had in the head and do you know the make or model?

Phil

MID-AIR

My Feedback: (10)

hi phill: dont remember the degree it was set at but the guy that trimed it out had no problem flying it, i think it was either a dc gyro or a wistler ido remember it had slanted up tips on the stab ,cant recall if it had a rudder or not. the head tilted left,right,forward and back, i will build another one ! i tried to turn it just useing the roter . not even shure if it had elevator. but then it was 3 years ago! illtry again. what is a good one to build easy now?

floridagyro

Hi,

The PT Gyro or the PT25 from http://www.flyingbalsa.com/ are good gyro kits or the SCAMP from Arizonia Autogyro.

Phil

MID-AIR

My Feedback: (10)

hi phill : its me again, my mind dont seem to do what it should, on my gyrace what i read is to use neg. pitch on the blades, im useing a clark y airfoil. neg. pitch seems backward to me i am shure i used pos. pitch on my first gyrace,same airfoil somewhere between 5&10deg. it flew great. i could be wrong its been a while. any ideas can you or anybody else shed some light on my dilemma. AL

floridagyro

Hi,
OK, the original blades for the Grace were just flat stock with a very negative pitch, the same designed used for windmill blades for pumping water. For running a mechanical water pump that was good because the speed was limited by the drag and it has good starting torque. However, that is not good for autogyros.

Your Clark Y provides fairly good lift but doesn't start well so the blades require a little shim on the trailing edge of the blade hub to get them started. Usually a couple layers of masking tape is all that is necessary. However, the SG6042 profile blade is much better because it can be mounted flat, with no shims, and provides more lift. If you have Clark Y blades made from wood, you can convert them to the SG6042 by sanding them a little thinner and sand a small area on the bottom the full length just in front of the trailing edge.

Phil

tintrax

I use delta angle hinges (15 degrees) and that takes care of the incidence. Blades mounted flat, I have used Clark Y and all is OK. Except yesterday I had a crash! Nothing to do with the rotors (but I did break one). Dark day, rain about, fresh breeze, plane got too far away, oriention difficult - Bump!! However not complete disaster as autogyros generally don`t hit too hard due to slow flight characteristics and repairs underway.
Colin

ciervapilot

Hi Phill!
Thank you for your help.
Here are some pictures of my new built rotor head and blades.

A Merry Christmas!

floridagyro

Hi,

Looks good. However, you will get more lift from the blades without the coning angle. The coning angle adds stability to a single rotor gyro but doesn't help with dual rotors.

Phil

ciervapilot

Hi Phil!
Do your two rotor gyros have a nose down angle (hang angle)?
I mean: If you hold the model by the rotor shafts and watch the nose down attitude of the model in reference to a horizontal line through the center of the fuselage to the tail.
How big is this hang angle?

floridagyro

Hi,
The hang angle is the same for both and single rotors. Suspend the dual rotor by the rotor shafts and set the thrust line angle to about -12 degrees.

For dual rotors it's real important to get both rotors running at the same speed on take-off. On the first flight it's best in a light breeze and point it straight into the wind and watch the rotors. But using the rudder you can bring the slower spinning rotor into the wind. Hand launch also works good as you can feel the rotors when they are pulling evenly. On a hand launch, be careful that it doesn't loop as the rotors will be proving a lot of lift. With hand launch tip the gyro up to get the rotors spinning until they start to really pull and then bring the fuselage level and give it light push.

Phil

ciervapilot

Hello Phil!
Thanks a lot.
Perhaps the CG point was the problem of my tango.
I 've built it as in the instructions, but when holding my model at the rotor shafts, it 's tail heavy! When I hold it at the CG point marked in the plan, it 's ok. Probably the CG is wrong in the plans.

Perhaps this is also a reason why it was so sluggish on the rudder at maiden flight.

Stefan

liljoe

Hello, I have a friend who has a 1940 tango gyro plane. I have searched high and low for one on the internet with no success except yours. The one he has is a bit different. Do you know where I can find information on it or a web site? His R/C gyro is huge compared to what I have seen here. It is vintage i know that much. He was thinking of putting it on E-bay but I can not find even a worth to start an auction. Thank you if you have any information that can assist me.