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Speed,Combat,Scale,Racing => Scale Models => Topic started by: jim gilmore on December 27, 2010, 02:46:09 AM

Title: juust a question on engines and wwi models..
Post by: jim gilmore on December 27, 2010, 02:46:09 AM
This a scale question that I am curious. Many years ago I was able to go to Rhinebeck ny and see their airshow. From what I remember they said that the aircraft or many wwI basically were either on or off . Not an  adjustable throttle.
So I'm just curious if any modelers have made a scale model that had a throttle that ran as either on or off ?
Title: Re: juust a question on engines and wwi models..
Post by: John Witt on December 27, 2010, 03:09:14 AM
I never had one of those that did that deliberately.   n~  However there have been a couple of discussions about how to do a rotary-powered scale engine set up for airplanes such as the various Nieuport fighters, Fokker triplanes, etc that used them. 

Those rotary engines did that with an interrupter button on the stick.  Basically ran wide open or off, with the ignition "blipped" to get an intermediate setting.  They had an extreme amount of torque induced roll because of this feature and the rotating engine.  It would be an interesting project to work out as, I think, the ailerons and rudder would have to work in concert with the on-off throttle to control the roll.  Add that to the ever changing cross wind that a ukie flies in and you have a real handling problem.

John
Title: Re: juust a question on engines and wwi models..
Post by: Tim Wescott on December 27, 2010, 11:19:20 AM
Those were 'rotary' engines -- not rotary like Wankles, but rotary like the crankcase rotated, you mounted the crankshaft to the airplane and the prop to the case.  Induction was through both the crankcase and 'backwards' through the exhaust -- so you really couldn't throttle the thing with a regular carburettor.  Hence the 'blipping' engine speed control.

Somehow I suspect that the inline and V engines had more conventional throttles.

Our engines have a much smaller moment of inertia to keep the prop rotating, so you couldn't turn the ignition off for very long -- I don't know if you could blip it long enough to be heard, unless you put a humongous flywheel on the thing.
Title: Re: juust a question on engines and wwi models..
Post by: John Rist on December 28, 2010, 06:39:55 AM
Of course it could be done with an electric.  Could have a blip button on the handle. Problem would be the sound. Solution for sound could be a sound chip and speaker system.  I am not sure it it would improve score over a conventional throttle/nitro 4C setup.  However regular throttle on an Eindecker would not be scale.  I don't know how the judges would react to this.

 HB~>
Title: Re: juust a question on engines and wwi models..
Post by: Chris McMillin on December 28, 2010, 09:53:17 AM
Some rotary engines had an interrupter circuit so the pilot could select a preprogrammed number of cylinders for "throttle" control. I saw a rotary powered Camel flying at Chino, Ca last couple of years that was so equipped and it made very distinctive sounds for each selection. If using electric and a sound card programmed to replicate this with a reduction in throttle it should be authentic. BTW, there is no visible jerking forward and aft/left and right, of the airplane while this is being used, the pilot adjusts the airplane in a normal way while taking off and landing. There were no odd movements of the airplane while using the blipper.
Chris...