View Full Version : New Russian contraption - II
08-06-2005, 07:55 AM
Last year I wrote about a guy here who was building a special gyro for AG-spraying, named "Adelle". Yesterday this gyro arrived at our airfield for ground tests etc.
It is powered now by Subaru EJ-20 though engine is still a question for future.
In front of pilot's cabin you can see a large luggage compartment which may host an 130-litre AG-tank.
Prerotator is hydraulic now though it should be replaced by small 2-stroke engine later or probably mechanical (constant speed joints) system.
Rotor is 30' SportCopter.
Prop - 5-blade Lugansk "Aero" prop
Landing gear was specially designed for rough fields.
Yesterday and today I touched it on lowspeed rolls without rotor. The gyro definetely needs a lot of small bugs to be fixed so flight tests are expected later this summer/fall.
A man on one photo - lucky designer Mr.Valentin Ustinov who came back to gyros after 30 years. He is the man who built gyros in Riga in late 60's - I posted at Tim's website his old movie with towed gyroglider on floats.
I cannot tell much about the design but a lot of job was done in aerodynamical and stress calculations: I saw their reports which weigh a couple hundred of pounds in paperwork :) Still curious how this works in fact.
08-06-2005, 01:08 PM
I like the looks of it in its own ugly way! Seems like a big suction area with how he just rounded off the pilot compartment, but whats it really matter to gyro's? Why the interest for this gentlemen to build a purpose built gyro for agricultural spraying, twistair, if I may ask? Is there not a lot of fixed wing ag sprayers over there? Or perhaps it is smaller fields better suited to the maneuverability and accuracy of rotorcraft sprayers?
Here in Montana, most of the fields are large (1 mile long) and fixed wing crop sprayers still do an alright business although the large capacity wide sweep purpose built crop sprayers have made quite a bit of inroads into the market. No rotorcraft hardly except for spot spraying of noxious weeds of government land. (Heli's, not gyro's.)
Thanks for sharing those cool pic's. darrellwittke
08-06-2005, 02:25 PM
It looks cool. I would like to see it fly.
I have just looked at the "contraption II" and must say that this is a excellent design in about all areas, the high cockpit is perfict for agriculture applications and the rotor is located in the proper ratio between the propellor and the rudder hinge line and the twin rudders are perfect for positive control at slow speeds, in other words I don't think "contraption " is a fair definition for this machine, but rather it should be called a well designed specific application aircraft. The only thing that I see that will most likely be necessary to change is the move to a JE 2.2 or a JE 2.5 engine for better performance, but perhaps availability or fininancing may delay this.
This machine could be a serious contender in the commercial market place of agriculture spraying
08-06-2005, 04:44 PM
Would a 5 blade prop run into stalled air from the previous blade at normal operating rpm's of the engine?
08-06-2005, 05:16 PM
Interesting how you always see Sport Copter blades used for high performance applications, not Dragon Wings, SkyWheels or hardly anything else. I'll bet those cost a fortune in Russia.
Here in the USA there really is only two choices for a machine that heavy.... Sportcopter or RAF blades. RAF blades are cheap compared to Sportcopters, but there is no knowing if your RAF hubbar will crack, or if some other problem will come along with them, so the Sportcopters may end up being a better buy.
Ernies 7 inch blades just don't do well with that much weight and he does not go after that part of the marketplace. I say he is missing the boat on that cause he makes a good product at a great price and if he had a 8 inch luxury blade like Sportcopters I think he would be selling every set he could make.
08-07-2005, 03:59 AM
I know he did make a set or two of 8".
08-07-2005, 04:12 AM
Yes he did, but they were a experiment and apparently he didn't like the results.
08-07-2005, 10:41 PM
Why the interest for this gentlemen to build a purpose built gyro for agricultural spraying, twistair, if I may ask? Is there not a lot of fixed wing ag sprayers over there? Or perhaps it is smaller fields better suited to the maneuverability and accuracy of rotorcraft sprayers?
Darrel, There are a lot of small fields here so most of AG-jobs are done by very light airplanes and - mostly - trikes. The idea is that gyro may operate these fields more safely but this idea is still to be proved. Hope that we can start to check this later this year and next summer.
Yesterday we installed rotor on this gyro and I tried to prerotate and do some take-off rolls.
I was not perfect describing it's current prerotator - sorry. Actually it already has a small 2-stroke 12 hp engine in engine compartment (note a small muffler slightly left and above main one). This engine is currently powering the hydraulic unit. One more interesting thing is that the prerotator liquid runs right through the front mast struts - saving the weight on long hoses.
On the start pilot may run main engine on idle, starts the small engine and prerotate. When the prerotator reaches it's maximum you just add main throttle and begin the take-off roll. Prerotator engine may be turned off by pilot at any time on take-off. Slightly unusual for me but it was very interesting. Supported by this small engine rotor easily reaches high rpm.
I will post when we move further with these tests.
Luc De Keyser
08-07-2005, 11:19 PM
From earlier threads I seem to remember that a partially driven rotor can be quite efficient. As this contraption II has its own prerotator engine, why not keep it running also after take-off?
08-08-2005, 06:14 AM
Luc, it's simple - we don't feel having enough experience for such serious innovations.
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