PennStateCK
New Member
Good Evening,
This is my first post so I hope it's not too dumb of a question. I'm designing a high performance, twin engine, light aircraft that would fly pretty well the the Starr Aircraft Black Flame 280 (35HP at around 20lbs), but might be a bit under powered. I know the 582 or the 503 weighs significantly more at about 100lbs fully installed, but the extra 30+hp/engine would more than make up for it.
Due to the to the pusher design, and the overall small size of the aircraft, I'm limited to a maximum prop diameter of 36" and even that would be pushing it for ground clearance. The ideal propeller would be a 3-blade 34x22 coupled directly to the output of the 582. My static thrust formula comes out with a HP requirement of about 60HP at 6000RPM with over 180lbs of static thrust! This would be perfect for the 582 if I could couple it directly to the engine. However, I haven't come across a single 582 or 503 out there that doesn't have a reduction gearbox?
Would it be acceptable to run a direct drive off of the output shaft? If not, would a simple adapter and bearing assembly make it acceptable to put the force of the propeller pushing into the engine block instead of on the crankshaft directly?
Thank you in advance for all of your help!
PS. If I were to run the 280, I'd probably have to step down to 30x15 running around 7000RPM. I haven't heard much about the 280 but their lifetime warranty makes me feel at least a little safer running a model aircraft with that engine. I would miss out on about 50lbs of thrust per engine though.
Black Flame 280
Rotax 582
Rotax 503
This is my first post so I hope it's not too dumb of a question. I'm designing a high performance, twin engine, light aircraft that would fly pretty well the the Starr Aircraft Black Flame 280 (35HP at around 20lbs), but might be a bit under powered. I know the 582 or the 503 weighs significantly more at about 100lbs fully installed, but the extra 30+hp/engine would more than make up for it.
Due to the to the pusher design, and the overall small size of the aircraft, I'm limited to a maximum prop diameter of 36" and even that would be pushing it for ground clearance. The ideal propeller would be a 3-blade 34x22 coupled directly to the output of the 582. My static thrust formula comes out with a HP requirement of about 60HP at 6000RPM with over 180lbs of static thrust! This would be perfect for the 582 if I could couple it directly to the engine. However, I haven't come across a single 582 or 503 out there that doesn't have a reduction gearbox?
Would it be acceptable to run a direct drive off of the output shaft? If not, would a simple adapter and bearing assembly make it acceptable to put the force of the propeller pushing into the engine block instead of on the crankshaft directly?
Thank you in advance for all of your help!
PS. If I were to run the 280, I'd probably have to step down to 30x15 running around 7000RPM. I haven't heard much about the 280 but their lifetime warranty makes me feel at least a little safer running a model aircraft with that engine. I would miss out on about 50lbs of thrust per engine though.
Black Flame 280
Rotax 582
Rotax 503
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