hawker seahawk

Hi there everyone,

I have been collecting C.30 full size infomation now for many years.

I now have enough info to build one to 1/3rd scale. All the blade rigging angles, C of G info, full size flying manuals, airframe rigging manuals etc......

I see no point in trying to re-invent the wheel, so to that end, I am looking to learn ,beg, borrow or even steal (well not steal !) infomation on how you all have sorted direct control in a radio controlled manor.

I know how it was done by the real aircraft. Now I need to learn how to do it in a large model form.

In turn I will do my best to help with info to anyone elce building a C.30.

Hope to hear from you all soon,

Gordon Fraser.

U.K.


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Bruce R B.

I too am interested in gyrocpters, and have done quite a bit of research. I recently purchased a semi-scale C30 kit made by LAheli (www.laheli.com). Although I've just begun construction I see that they call for Delta mixing on the radio. This particular kit uses only two servos; no rudder or elevator. The servos are mounted at 90 deg. to each other; one directly behind the rotor and the other to one side. Why they call for Delta mixing I don't know; one would think that simple aileron and elevator controls would sufice, but I assume they know what they're doing!

hawker seahawk

Hi There Bruce,

The origanal C.30.A Autogiro also never had an elevator or rudder at all !

As I am sure you know, the best way to think of the flying controls on an autogiro is to think of the rotors as a disk or a flat plate.

While this disk is horizontal through all plains, the aircraft would just sink vertically.

By tilting the disk in the direction you want to go the aircraft will move in that direction.

Thats why there are the two servos. one for forwards and backwards. The other for left or right. By mixing the two servo imputs the disk can be pointed in any direction theough 360 Deg.

It is this movement that makes the C.30.A autogiro so special as it was the first autogiro to completely do away with convenional controls as in an aeroplane, (See the early autogiros like the Cierva C.19).

I will confess to not understanding the term "delta" mixing, but I would also have thought that aileron / elevator mixing would indeed do.

good luck with your model,

Gordon Fraser.

Bruce R B.

Hi Gordon,

         Yes, I am aware of the physics behind the operation of an autogyro.  What puzzles me is the reason for the Delta mixing.  I'm thinking it must be to do with the gyroscopic precession caused by the inertia of the rotor as you attempt to tilt it one way or another.

          Deta mixing is used with Delta wing aircraft which have an Elevon on each wing.  An elevon serves the function of both an aileron and an elevator.  As ailerons the elevons move in opposite direction to produce the roll required to turn the aircraft.  As elevators they move in unison to produce the pitch for ascending or descending.

          Any decent computer radio will have Delta mixing in its repertoire.  One servo plugs into the aileron channel and the other in the elevator channel.  You can also purchase an seperate mixer from E-flite which plugs into the same channels on an older non-computer radio.

Luck, Bruce

hawker seahawk

Hi Bruce,

All makes sense to me sir. Never heard of elevon mixing being called "delta" mixing before though. Must be an American term......

Did you know that the tailplane on the C.30 is handed ?

One side has an inverted wing section. The reason for this is to counter act engine torque. the small movable tabs on the tailplane are fixed trim tabs that can only be changed on the ground.

Yours,

Gordon.

U.K.

Bruce R B.

Hi Gordon,

Thanks for the info on the tailpane; didn't know that!  I don't know why the mixing is called "delta mixing" except that it is used, of course, on delta wing aircraft.

I'll try to get my C30 up and running ASAP and let you know how it behaves with and without the mixing.

Bruce

imsofaman

My Feedback: (2)

Bruce....what is the issue again??? What model do you have? Listen....this is easy. Delta wing mix is used whan using two servos to control the roll and pitch. This is also refered as load sharing setup. The other set up is just having one servo for pitch and servo for roll. that is when you use just standard fixed wing settings.

Hope this helps.....let me know if you need more help?

Dave

imsofaman

My Feedback: (2)

Bruce.....I just read through your post again for the LA Heli Cierva C-30. You must use delta wing setting as it is a load sharing set up.

Dave

baronrouge

Hi Gordon,
I'm building too a Cierva C-30, from Aerotech plans. Rotor span about 75", ASP 70 FS engine. I'm about finishing it. I'll send you some pictures.
In past august, I took some holidays in Leatherhead, near London, and I visited RAF museum. What a surprise when i saw a real C-30 in here: I completely discharged my camera taking photos !!!
If you want 2 really good books about Cierva's autogyros, lets try "LA CIERVA AUTOGIROS" TMA editions, by José FERNANDEZ, Juan Arraez CERDA y Arnaud PRUDHOMME, and "les autogires LEO C-30 & C-301 by Jacques MOULIN, Collection Profils avion N°5.
Many many pictures and drawings;

Jérôme

gyronuts

I have the book that you are referring to on the C30.
It is advertised for sale.
see http://www.bmfaclassifieds.co.uk/detail.php?id=14417

Bill