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Speed - Performance - Drag Race > How fast will my heli go ?

Raptor-30-V2
Veteran
Location: Norway : Sarpsborg - Hammerfest

How fast will my Raptor 30 V2/w TT Pro-39H engine go ? ( In km/hour )
All my friends ask how fast it goes, but I dosen't realy now...

Thanks!

[size=large][b][url=www.runryder.com/gallery/07903/]My gallery[/url][/b][/size] 3DM 2005 Here I come

07-03-2003 Over year old.

corey11
Elite Veteran
Location: Bay Area, California

your heli will go about 140 mph when the blades stop at about 400 feet..

does that answer it?

it will probably go between 40-60 mph

07-07-2003 Over year old.

HOMEPAGE

frode
Heliman
Location: Drammen, Norway

I zip-tied a gps on my Freya once. Think it did 120-130 km/t..

07-07-2003 Over year old.

plumlazy
Heliman
Location: Columbia, S.C., Usa.

re: How fast will my heli go ?

If speed were directly proportional to looks then that would be one fast heli, because it sure does look good.

Nice paint job !

07-12-2003 Over year old.

YSRRider
Key Veteran
Location: Ingleside/Fox Lake, IL

how high will it go?
how much does it cost?
can i fly it?
is it hard to fly?
how fast does it go?
will those blades hurt if i get hit by them?
did you build that yourself?

Ignorance!!!!!!

12-17-2003 Over year old.

ReadyHeli
rrAdvertiser
Location: Jupiter, FL

Hey YSRRIDER,

Why is it ignorant?

All he did is ask a question?

Isnt that what this forum is for?

Old and New pilots helping out alike?

Whose ignorant?

If you are tired of hearing such ignorance, perhaps you need to retire.

As for me, I think there is nothing wrong with asking a question about a RC Heli at a RC Heli Forum for SPEED.

Life is too short to be a hard-on with someone who looks to YOU for help.

JG

John @ Readyheli

01-03-2004 Over year old.

Glenn in Den
Key Veteran
Location: Longmont, Colorado area

Why are you only scolding him? Only ONE person answered the question so far! Even you and I didn't answer it ('cause I don't know!!)

Glenn.

I'm not really an R/C pilot, I stayed in a Holiday Inn Express last night!

01-04-2004 Over year old.

ReadyHeli
rrAdvertiser
Location: Jupiter, FL

Good point Glenn.

It is sad to see someone call someone else names however, when they are here to learn.

Thats the point I was making.

JG

John @ Readyheli

01-04-2004 Over year old.

J_DOGG
Heliman
Location: Zanesville, Ohio

Raptor 50V2 OS 50

Anyway, back on the old subject...........

I had my friend, checked the speed of mine one time (when I accidently brought the Marksman Laser home with me), with a police laser, only hit it one time and said 48 mph. I was flying it slow so that he could hit it. I didn't have any reflective tape on it (forgot to bring it) so I he could get a good hit on it.
This summer (when I forget to leave in my work car again and bring it home) I will check it again and remember the reflective tape. I would have to guess and say it will do 75 to 80 mph.

01-05-2004 Over year old.

armageddon
Veteran
Location: Monroe, N. Y. Posts: -99999

t = time
acceleration = 9.8t
velocity = what the hell do I know...

it comes down fast...

01-07-2004 Over year old.

kauaison
Senior Heliman
Location: Alameda, CA

i heard of a few people doing speed tests, from what i remember it took a few tries....steeeep dives, full accell with a 90engine with the wind, its possible to hit 100mph (160.9kph), as for a 30/50 im guessing 60-70mph (95-115kph) tops....

01-07-2004 Over year old.

pistole
Veteran
Location: Heli Land ....

The faster I go , the more my testicles shrink.

Therefore , when I can't feel my nuts anymore , I know that thats the absolute limit.

I understand that guys like CY , JK and AS have BIG BRASS ONES that you can hear clacking when they walk into the room.

Cheers.

Rap70. TT70.Rap50. TT50.RD8000.

01-07-2004 Over year old.

Chopper Man100
Veteran
Location: albany N.Y.

Sorry, I have to say this

You shouldn't be feeling your nuts when your flying your chopper anyways. Keep your fingers on the sticks, its safer. (and thats means the sticks on your transmitter). Have a nice day. Again, sorry but I couldn't resist the comment.

02-29-2004 Over year old.

NYJR13
Heliman
Location: New York City, New York, USA

Its not hard to figure out, first, no matter your engine and heli, take it into slowish foward flight then find a way to push it as forward angle wise as it can go while still staying in the air, measure that angle, that teh amount of joules that your setup pust out and do the math what ever is remaining will be how much force. then multiply by weight in kilos, and figure out km/h.
Or instead of the angle thing, figure out total amount of newtons produced, subtract 9.81N/s and thats the force with which you can accelerate the helicopter, then take the normal drag coeficcient of the atmosphere at your particular altitude, and calculate the speed of the air coming from underneatht he blades at full throttle, that is pretty much your limit, so with 0 and that as your limits, dust off your calculus book from high school and figure it out. Will take around a solid hour or two. Or you can sit in a car, fly it up to top speed next to the car, while your friend drives along a long stretch of open road (i.e. the runway at floyd-bennet field in NYC)
Hope this helped. Im too lazy to calculate myself

Winning the fight against gravity 24/7

03-12-2004 Over year old.

Joojoo
Heliman
Location: Gainesville, FL

If I understand correctly, the maximum speed of a helicopter is largely a function of the headspeed. Technically, the higher the headspeed, the faster the helicopter can fly in forward flight. The speed limit comes from the stalling the retreating rotor blade at high speeds.

As the helicopter starts moving forward, one side of the blades (left side for most models) advances into the freestream airflow while the other side (right side) retreats or moves away from the airflow. Essentially, this makes the left side of the rotor disc see a higher airspeed than the right side. The rotorhead compensates for this through blade flapping, changing the blade angle so that the high airspeed seen on the left is met with a low angle of attack, and the low speed on the right is met with a high angle of attack. In trim, the total lift from each side is equal (or at least the moments) are and the helicopter flies straight ahead.

If you consider a helicopter with a 50" rotor span and a headspeed of 1800rpm, you can calculate the tip speed as 267.7MPH or 430.9KPH. This is the theoretical maximum speed if you neglect blade stall angle and drag rise. If this were to happen, the last bit of lift on the right side would come solely from the extreme rotor tip. However, when blade profile characteristics are taken into account, the maximum speed is reduced considerably. You'd have to know the lift and drag polar of your particular blade section at your particular Reynolds number to accurately compute the max speed.

The rotor blades are said to stall at an angle of attack of 14 degrees, which accounts for the large difference between the 'theoretical' maximum and the actual maximum speeds of approx 70MPH for the helis.

Here's a nice reference for additional information and a much better explanation:

http://www.dynamicflight.com/aerodynamics/retreating/

NYJR13,

I see where you're going with your explanation, but I don't think it will give you very accurate results. The forces in place during a hover are inherently quite different than the ones in forward flight. It's the asymmetry of the lift that causes the problems of speed limitation, and this is more a function of rotorspeed than engine power at hover or slow forward flight.

05-10-2004 Over year old.

Joojoo
Heliman
Location: Gainesville, FL

corey11,

I think you had the most correct answer. If you could get the blades to fold back at a few hundred (maybe thousand) feet, the heli would likely point straight down and hit at least a buck fifty on it's way to terminal velocity.

May I recommend a crash kit?

05-10-2004 Over year old.

mrhelichopper
Heliman
Location: The Netherlands

As correctly stated retreating blade stall is one factor affecting the maximum speed that can be achieved by a helicopter.

Other factors also have an affect and it is not always retreating blade stall that limits a helicopters maximum speed. Personally I have never seen or experienced retreating blade stall with a model helicopter.

Some other factors which have an effect are:

Advancing blade speed. The drag on the advancing blade is proportional to the square of the velocity of the blade. As the speed of the helicopter gets high this means that the drag on the rotor disk increases dramatically the engine has to work hard just to keep the rotor Rpm up so we can run out of power.

Rotor tilt. The helicopter is propelled forward by the horizontal component of rotor thrust. The amount of rotor thrust we can tilt forward depends on how much we can tilt the disk forward against the tendancy of the helicopter to remain horizontal. Cyclic authority comes into play here on most model heli's have lots but the tendancy of the heli to remain horizontal varies model to model. Fast full size helis have the mast tilted forward so no cyclic input is required to tilt the rotor forward.

Aerodynamic efficiency of the fuselage, simply the more slippery the faster it goes for the same power.

At the end of the day we need to overcome drag be it rotor drag or profile drag (pushing the thing through the air). efficient blades, slipery fuselage and a mechanical set up that allows us to proportion the maximum amount of rotor thrust to the horizontal component whilst retaining the required amount of vertical, and increasing these drag factors by the least amount possible help to achieve the highest speed possible.

after all that never measured a raptor 30 so don't know....

05-11-2004 Over year old.

FLYINFOOL
Veteran
Location: Cudahy, WI

Had the local police clock a R30 once.
It hit 72MPH (116KPH)
This was in a slight dive to head straight at the radar gun, but coming out of a steep dive.

I do NOT recommend buzzing the local law enforcement with a heli.

Jeff Borowski
Gohbee Field Rep
0133TD

06-30-2004 Over year old.

HOMEPAGE

cjw
Veteran
Location: UK - Cheshire

I timed my Fury a little while ago by filming it crossing two points where I new the distance, then measured the time from the video.

It wasn't going as fast as it can, but in straight flight averaged over 80mph

Clive

07-19-2004 Over year old.

HOMEPAGE

SkateFreak
Key Veteran
Location: Cambs UK/Luton

as simple as....
Okay, u guys have all the fancy methods....
Why not mark out a designated length of which u know the distance etc etc etc...
The simplest ways are sumtimes the best

07-25-2004 Over year old.

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