Gyro Jim
Newbie
Hi Guys,
My name is Jim Sharer. I live in upstate NY. I built and fly a Little Wing with a 912 HP up front, a delightful aircraft with a great little engine.
Over the last year, a gyro friend and myself have been working on a Yamaha Phazer 80 HP snowmobile engine conversion. We have it mounted on my buddy George's Air Command gyro. George is a long time gyro pilot with 800+ hours. We have gotten it to the point where it is up and running well except for a persistent vibration. It's a high-frequency vibration, a buzz, that carries down through the air frame. My best guess at this point is that it's a harmonic vibration that is occurring between the 2 gear boxes. The Yamaha 80 has a built in gear reduction. The only solution I can think of trying is to change the gear ratio in the Rotax c-box. This hopefully may upset the harmonics, eliminating the vibration. I have been in contact with Todd (Racer) about it and I think we have exhausted all other possibilities. I have also talked with Dick Dougherty, he is also working on a 80-HP Yamaha but is not quite as far along.
So, my question is: is there anyone out there that has a gear set we could borrow, rent or buy? We are now running a 2.62 to 1 gear set. I would like to try a 3.47 or perhaps a 3.00 would do the trick. Thanks.
Gyro Jim
My name is Jim Sharer. I live in upstate NY. I built and fly a Little Wing with a 912 HP up front, a delightful aircraft with a great little engine.
Over the last year, a gyro friend and myself have been working on a Yamaha Phazer 80 HP snowmobile engine conversion. We have it mounted on my buddy George's Air Command gyro. George is a long time gyro pilot with 800+ hours. We have gotten it to the point where it is up and running well except for a persistent vibration. It's a high-frequency vibration, a buzz, that carries down through the air frame. My best guess at this point is that it's a harmonic vibration that is occurring between the 2 gear boxes. The Yamaha 80 has a built in gear reduction. The only solution I can think of trying is to change the gear ratio in the Rotax c-box. This hopefully may upset the harmonics, eliminating the vibration. I have been in contact with Todd (Racer) about it and I think we have exhausted all other possibilities. I have also talked with Dick Dougherty, he is also working on a 80-HP Yamaha but is not quite as far along.
So, my question is: is there anyone out there that has a gear set we could borrow, rent or buy? We are now running a 2.62 to 1 gear set. I would like to try a 3.47 or perhaps a 3.00 would do the trick. Thanks.
Gyro Jim