carey shurley
03-21-2011, 07:20 PM
For the most part, gas powered helicopters aren't designed much different than their glow powered equivalents. They are usually a variant of an existing glow or electric powered model but the frames are changed to allow the physically larger motors to fit. A different engine mounting arrangement is necessary, the gearing and cooling systems are changed and sometimes the clutch is changed to address lower operating RPM's. The main and tail rotors and control systems are not unique
what is unique from a helicopter perspective is the motor itself. To date all gas powered helicopters have adapted existing industrial motors, most commonly those used for yard equipment (blowers, trimmers, etc). All glow motors have been developed specifically as model engines and I suspect the bulk of the current crop of electric motors are as well.
The Dubro Shark helicopter, circa 1972 appears to be the very first commerically made gasoline powered helicopter. The Shark (designed by Dave Gray in 1970 who is now in the AMA hall of fame) was fixed pitch and VERY heavy as it was all aluminum and steel. It was originally powered by an O&R (Ohlsson & Rice) motor that was rated at 1HP.
http://helifreak.com/attachment.php?attachmentid=92104&d=1239892932
It was seriously underpowered and was later rekitted as the Dubro Shark 60 which used glow powered 60 sized models. I owned a Shark 60 and it was indeed capable of flight but with fixed pitch and NO GYROS it was a handful - but I digress.
Over the years its amazing just how many commercially available gas powered models were created by various manufacturers.
A quick list: (not in historical order) Kalt, Hirobo, TSK, Kobe-Kikko, Miniature Aircraft, Bergen, Century, Vario, Airstar, Maxxum, Quick, Helibug, JR, Robbe, RJX and even Yamaha. They all shared something in common, they all (except for two) use single cylinder, air cooled two stroke industrial motors.
Yamaha built a custom water-cooled twin cylinder motor for their RMAX
Hirobo used a Tanaka 24 in the Eagle Gas
TSK also used the Tanaka in the Mystar Gas
Kalt used a KG22 motor in the Baron GS
Kobe-kikko used a Kioritz motor in their R22 and Hughes 300 models
Bergen also developed a twin cylinder air cooled motor based on Zenoah parts
RJX uses a chinese developed CRRC motor
All the others have used different formats of available motors from Zenoah in Japan. Far and away its been the most popular choice for a gas powerplant.
As a side note, I visited Zenoah’s website and found the following reference:
The name of Zenoah" is created by combining the prix "ZE" meaning "to challenge the future" with "Noah" from the biblical story of Noah's Ark. The logo features a red circle and white arrow with the circle representing a global world and the red color representing our product color and innovation while the white triangular arrow represents the sail of the ZeNoah ship; "MOVING FORWARD" to symbolically show the brand heading into the future.
They've been making these little engines for about 100 years. Obviously making model helicopter motors is not their main focus, however they do manufacture the Red Max line of yard tools. Next time you see one of these, take a look at the motor. It will look very familiar.
Historically the favored motor configuration has been something similar to this:
http://www.helifreak.com/attachment.php?attachmentid=184930&d=1287095057
It uses a magneto ignition system, diaphragm carbureted no cooling system provided. The early versions assumed that a large flywheel fan was going to be installed (remember industrial purposes) and had much smaller/thinner cooling fins.
By adapting the raw motor to save weight, the helicopter mfgrs needed to find a way to mount the motor and adapt a cooling system. Until just a few years ago, this meant they just took the cooling system from their glow helicopter and found a way to mount it on the motor.
Since glow motors derive a lot of their cooling from the fuel and oil they need less air flow.
Gas motors have to dissipate their heat via their cooling system. So most if not all of the setups simply didn't cool very well, would overheat under load, lose power, and stop running (always at the worst possible moment).
Later an improved version was created by Zenoah which had more cooling area and some other internal changes. Here's a current production Zenoah G231. You can see the improved fin area
http://helifreak.com/attachment.php?attachmentid=216482&stc=1&d=1300751935
Having now given you some history, the next installment will address the motor types in use today and where they seem to be going.
The Bottom Line:
Gasoline helicopters have been around for a long time but many them have shared a common motor
what is unique from a helicopter perspective is the motor itself. To date all gas powered helicopters have adapted existing industrial motors, most commonly those used for yard equipment (blowers, trimmers, etc). All glow motors have been developed specifically as model engines and I suspect the bulk of the current crop of electric motors are as well.
The Dubro Shark helicopter, circa 1972 appears to be the very first commerically made gasoline powered helicopter. The Shark (designed by Dave Gray in 1970 who is now in the AMA hall of fame) was fixed pitch and VERY heavy as it was all aluminum and steel. It was originally powered by an O&R (Ohlsson & Rice) motor that was rated at 1HP.
http://helifreak.com/attachment.php?attachmentid=92104&d=1239892932
It was seriously underpowered and was later rekitted as the Dubro Shark 60 which used glow powered 60 sized models. I owned a Shark 60 and it was indeed capable of flight but with fixed pitch and NO GYROS it was a handful - but I digress.
Over the years its amazing just how many commercially available gas powered models were created by various manufacturers.
A quick list: (not in historical order) Kalt, Hirobo, TSK, Kobe-Kikko, Miniature Aircraft, Bergen, Century, Vario, Airstar, Maxxum, Quick, Helibug, JR, Robbe, RJX and even Yamaha. They all shared something in common, they all (except for two) use single cylinder, air cooled two stroke industrial motors.
Yamaha built a custom water-cooled twin cylinder motor for their RMAX
Hirobo used a Tanaka 24 in the Eagle Gas
TSK also used the Tanaka in the Mystar Gas
Kalt used a KG22 motor in the Baron GS
Kobe-kikko used a Kioritz motor in their R22 and Hughes 300 models
Bergen also developed a twin cylinder air cooled motor based on Zenoah parts
RJX uses a chinese developed CRRC motor
All the others have used different formats of available motors from Zenoah in Japan. Far and away its been the most popular choice for a gas powerplant.
As a side note, I visited Zenoah’s website and found the following reference:
The name of Zenoah" is created by combining the prix "ZE" meaning "to challenge the future" with "Noah" from the biblical story of Noah's Ark. The logo features a red circle and white arrow with the circle representing a global world and the red color representing our product color and innovation while the white triangular arrow represents the sail of the ZeNoah ship; "MOVING FORWARD" to symbolically show the brand heading into the future.
They've been making these little engines for about 100 years. Obviously making model helicopter motors is not their main focus, however they do manufacture the Red Max line of yard tools. Next time you see one of these, take a look at the motor. It will look very familiar.
Historically the favored motor configuration has been something similar to this:
http://www.helifreak.com/attachment.php?attachmentid=184930&d=1287095057
It uses a magneto ignition system, diaphragm carbureted no cooling system provided. The early versions assumed that a large flywheel fan was going to be installed (remember industrial purposes) and had much smaller/thinner cooling fins.
By adapting the raw motor to save weight, the helicopter mfgrs needed to find a way to mount the motor and adapt a cooling system. Until just a few years ago, this meant they just took the cooling system from their glow helicopter and found a way to mount it on the motor.
Since glow motors derive a lot of their cooling from the fuel and oil they need less air flow.
Gas motors have to dissipate their heat via their cooling system. So most if not all of the setups simply didn't cool very well, would overheat under load, lose power, and stop running (always at the worst possible moment).
Later an improved version was created by Zenoah which had more cooling area and some other internal changes. Here's a current production Zenoah G231. You can see the improved fin area
http://helifreak.com/attachment.php?attachmentid=216482&stc=1&d=1300751935
Having now given you some history, the next installment will address the motor types in use today and where they seem to be going.
The Bottom Line:
Gasoline helicopters have been around for a long time but many them have shared a common motor