I know it is a reach, but looking for plans for the lightest gyro rotorhead with pre-rotation

skyguynca

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I know a few of you guys out there have designed or got permission to copy a really light rotor head for your ultralight gyros that include the option of pre-rotation.

I am not looking to steal anything, just hoping I can get some drawings or CAD files to produce ONE(1) rotor head with your permission for an ultralight airframe I have ready minus head and blades. I have the blades now looking for a head that will save me a few pounds and days if not weeks in experimentation of a new head design.

Please contact me at email skyguynca at yahoo dot com or PM me on here.


Thanks
David
 

Jazzenjohn

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The stock Bensen head is very light and the Bumblebee head is too. The Bumblebee head has to be modified because it uses a different teeter bearing scheme than most others. I have notes for the head I'm currently using but they are not very well documented since I change things so often. My current head is based on a modified Bumblebee head for the top half and a modified Bensen bottom half. The lightest prerotator system might be by using a cordless drill motor which makes it Not counted weight due to the battery, esc, and motor being tossable before flight, or baggage if it is carried, since it isn't part of the plane nor necessary for flight.
 

skyguynca

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The stock Bensen head is very light and the Bumblebee head is too. The Bumblebee head has to be modified because it uses a different teeter bearing scheme than most others. I have notes for the head I'm currently using but they are not very well documented since I change things so often. My current head is based on a modified Bumblebee head for the top half and a modified Bensen bottom half. The lightest prerotator system might be by using a cordless drill motor which makes it Not counted weight due to the battery, esc, and motor being tossable before flight, or baggage if it is carried, since it isn't part of the plane nor necessary for flight.
Ok, thanks. I have drawn both up in SolidWorks. I will have a look at combining the two.

I have thought about the cordless drill motor before, but all I have read on them is not really lot of rpms. I was thinking of making a electric prerotor like the one being discussed on a thread on here. I think I actually have all the componnents. However have it a temp connection like you would use for the drill but as a snap on unit you can disconnect and maybe a storage hooks under the seat to carry it along.....not sure working on keeping it light.

Thanks John


David
 

Georgi

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Ok, thanks. I have drawn both up in SolidWorks. I will have a look at combining the two.

I have thought about the cordless drill motor before, but all I have read on them is not really lot of rpms. I was thinking of making a electric prerotor like the one being discussed on a thread on here. I think I actually have all the componnents. However have it a temp connection like you would use for the drill but as a snap on unit you can disconnect and maybe a storage hooks under the seat to carry it along.....not sure working on keeping it light.

Thanks John


David
I don't know anything about this rotor head but like very much for "the minimum parts" attachment to the mast. I would like to ask gyrojake about the best-suited aluminum for it. Also, wonder how to determine the angle of the mast (there are no cheek plates to play).
 

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gyrojake

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That's a Ken Brock rotor head with a European twist to the torque tube.
Nice looking out fit
 

Georgi

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That's a Ken Brock rotor head with a European twist to the torque tube.
Nice looking out fit
Thank you, Jake. Any cons with this design? And, repeating myself, what material would you use for this head? Do you know any calculations/technics to set such mast up (without the benefit of cheek plates)?
Thank you, Georgi,
 

Aviomania

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This is the lightest rotorhead and prerotator cabable of 140 Static rpm and boosting to 340 RPM during ground roll. It was fitted to the original Aviomania Genesis G1sa "The Grandmother".


6 ultralight.jpg7 ultralight.jpg
 

Aviomania

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Here you can see the testing we did back in 2009.

and here you can see it close up in the beginning of the video:

I still use it on the "Grandmother" today... although i changed the rotorhead to one of our newer models.
 

Georgi

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Here you can see the testing we did back in 2009.

and here you can see it close up in the beginning of the video:

I still use it on the "Grandmother" today... although i changed the rotorhead to one of our newer models.
So, what happened to it? Why did you stop working on it? People were excited and I was personally ready to order this rotor head - electric pre-rotator assembly. What was (is) the final weight of it? What batteries do you use? Thanks. Georgi.
 

skyguynca

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So, what happened to it? Why did you stop working on it? People were excited and I was personally ready to order this rotor head - electric pre-rotator assembly. What was (is) the final weight of it? What batteries do you use? Thanks. Georgi.
Price in USD to include shipping?
 

Aviomania

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Georgi, David,

The weight of the UL rotor head is 2.5 Kg. (5.5 Lbs) The weight of the prerotator is 3.8 Kg (8.4 Lbs).
You can use LiPo or Life bateries (600-800 Grams or ~1.5 Lbs that you have to charge before flight) or you can use 2x 12V 9Ahr jel bateries that can be charged by the engine (5Kg - 11lbs).

The prerotator is fully developed and we have sold several units... but it is expensive, ( about 2K) more complicated and expencive to maintain/ repair......

The mechanical prerotator is cheaper 1200-1400 euros easyer and cheaper to maintane and operate and more robast. The only benefit of the electric is the weight savings. People who bought it was so they can stay part 103 leagal with a working prerotator.

In my experience most people who look or experiment with electric prerotators is so they can have a cheap prerotator... and not so they can save weight. If someone needs a lightweight system... it is available... but at 1950 Euros is not something that everybody will buy.

Rotorhead prices start from 600 euros.

I might have a used UL and an aircomand rotorhead (2.5 Kg and 3.5 Kg) somewhere..... i took them out in working condition... but the bearings will need to be changed.
 

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Gyro28866

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I had a Wunderlich prerotor on my Mac powered Bensen. The lower unit failed and I removed it and the drive cable. Leaving the upper unit in place. I noticed a 3/8 socket drive would fit. I purchased a Kobalt drill motor at Lowes and it would spin my Bensen blades to 110 rrpm. Use the drill to prerotate and pitch the drill motor overboard, and go.
At Benesen Days, I would prespin at the intersection by the tent and pitch the drill overboard and back taxi to the north end and taxi out onto the runway and go. No problem.
At Mentone, kinda the same. Paul the AirBoss just didn't understand.
and before prespinning and back taxi to the north end. It sure got Scott Lewis excited with the drill hanging on the front left side of my seat.
 
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