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Mikado Modellhubschrauber . GrandRC . CanoMod

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Blades, Night Flying and Painting > big blades
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

How big of blades would you need for a 8 foot fuse ?
08-01-2002 Over year old.
 
 
BladeRunner
Elite Veteran
Location: Ontario Canada. Member of "some sort" s

Big??

How big?? Need more info,
What application, what weight, scale....etc. etc. I think mostly it depends how big the tail rotor is and how much room there would be between the tip of the main and the tail rotor blades......don't want them to be close enough to touch, also the type of flying intended.......
08-01-2002 Over year old.
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

Hi

It's an experimental heli, I don't have a scanner but I could send the drawing of it via a fax.It will have a scale head , 5 blades ( black ), no weight determined, but it should not go over 40lbs ( with every thing installed ) I want a big engine 40cc range, with mechanics based on the Eagle 2 GS .but I don't know sizes or ranges for large scale blades !?The tail rotor is enclosed, 8inches.I might move it up to 10.
08-01-2002 Over year old.
 
 
BladeRunner
Elite Veteran
Location: Ontario Canada. Member of "some sort" s

Big??

That sounds VERY interesting, try a search here for that Yamaha R-Max......I think that's what it's called. This is an industrial heli used for crop spraying and other things.......you may get some useful info from that, one version has a 50cc liquid cooled 2 sroke engine....I think!!!.........
08-01-2002 Over year old.
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

Thanks BladeRunner, I found it and replyed to it in the Main Descussion forum.
08-01-2002 Over year old.
 
 
freestyle
Veteran
Location: Redmond WA USA

TG and Vario both make blades in the 810mm range. That would give you a rotor diameter of about 1.8 meters (6 feet) depending on the dimensions of the head itself. I think NHP has 800s now as well, but I'm not certain.

Are you scaling down a fullsize heli? If so you should be able to get the desired rotor blade dimensions by scaling down the real heli's dimensions. You might also consider re-scaling the project to suit the largest blades you can find on the market.
08-01-2002 Over year old.
HOMEPAGE  
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

 big blades

TG and Vario both make blades in the 810mm range. I think NHP has 800s now as well.Who is TG ? & who is NHP ? I have designed my own heli, all the stuff out there is either pod and boom or some stand off fuse, So I designed my own.I could fax some drawings of it to you , if you want.
08-02-2002 Over year old.
 
 
Twobeers
Key Veteran
Location: Toronto, Canada

the rmax is powered by a water cooled 246cc horizontally opposed 2 cylinder motor, the rotors are about 12'

I lost my infamous tag line.
08-02-2002 Over year old.
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

so......

Hey Twobeers,

What kind of rotor head would I need for a 8' fuse ? would the main rotor blades also have to be 8' with head ? it's an enclosed tail, scale fuse I could send you a fax of what it will look like ,if you want. Do you deal with big scale machines ?What kind of engine would i need ?
08-02-2002 Over year old.
 
 
RappyTappy
Elite Veteran
Location: Las Vegas, NV

Check out Cyberheli. I saw that you can have custom order carbon fiber reinforced blades made up to 950mm. Take a look http://www1.cyberheli.com/SAB/index.htm

Chris
Xero G

Forever Brothers
Mickey Tylo
08-02-2002 Over year old.
HOMEPAGE  
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

stupid question

How do you convert inches in to millimeters ? and vice versa
08-02-2002 Over year old.
 
 
woody
Senior Heliman
Location: Nothwest Pa.

conversion

multiply mm's by .03937 to get inches
multiply inches by 25.4 to get mm's.
08-02-2002 Over year old.
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

blades

When they list blades, say 900's .900mm x 0.3937( to convert it into inches ) only comes out to 35.433 , so is that per blade ? or what ?bottom line how can you determine the size of blades in inches, by there mm size ?
08-03-2002 Over year old.
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

when manufactures sell blades and list them , say 500's.Is 500mm the total ( ie both blades and head ) or just both blades ? I need a set of blades that are ( per blade ) 3' 6" long. and where can I get a 4-bladed head that is 1' 2" long, and 2" thick at the main shaft, and 1" thick at the blade connector point ?
08-04-2002 Over year old.
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

I do....

I know the inch sizes but I don't know how to convert them.

Each main blade: 3' 6" with a 3inch mounting surface ( what goes into the hub for bolting )

The rotor head ( 4-bladed ) would be 1' 2" long and 2" thick at the center and 1" in dia at the blade mounting point.
I am going to end up maching a new head unless i can find one .

the tail is built in so the fenstron blades with the hub would be 10" and the blades them selves would be 7" past the hub which is only 3".

So how do I get the length of the blades , main and tail ?and the rotor head ?
08-04-2002 Over year old.
 
 
Guardian
Senior Heliman
Location: Sarasota, Florida

The total length is 3' 6" with the mounting surface.

I come from a plane flying backround so most of your questions are "new" to me.

Have you figure out all the stress limits on a rotor head turning blades like this. No, I don't know how to measure the stress limits.

How many RPMs can you safely turn on the head with this type of setup. I don't know how to calculate the RPMs vs. the head with a four bladed setup.

How much dampening is the head going to require. I don't know how to measure dampening.

How much do the blades need to Lead/ Lag and does it need to be have Lead/Lag limiters? I don't know . I don't know .

Do you think a 10 inch diameter tail rotor is sufficent enought to compensate for the torque of a 100 inch main rotor system? It will be a 96inch M/R system . Should I use a 100inch instead ? I am going to bump it to a 14 maybe 16 inch dia.

There is many more factors, have you started working on any of them yet?

Yes but I need help , thats why I love this site every body help everyone, so will you help me figure the answers to your questions ?
08-05-2002 Over year old.
 
 
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Blades, Night Flying and Painting > big blades
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