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Some helicopter main rotor blades spin at roughly 185 rpm and extend out up to 20 ft so your question is subjective to the helicopter you are speaking of.
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What is CNC manufacturing?
CNC stands for Computer Numerical Control. It refers to a type of milling or manufacturing machine that is computer guided, with the ability to change tools, bits, blades, or tips.
What is tire feathering?
How Should I Know? I'm the same as you! Looking for Answers that isn't even Shown!
What are inserts in machining?
Tool inserts can be made of industry grade diamond, and various other ceramics such as tungsten carbide - which is most common. Tungsten tips are made by pressing the powered material into the tool tip shape (usually a diamond/kite shape for turning tools, triangles for milling) and then heated so the particles bond to each other. These tips can be fixed to the tool body and then used to machine, on a lathe or mill. The advantage of tip tooling is if the tip breaks only the tip needs replacing not the whole tool, or having to grind the worn tool. However tungsten will not tolerate intermittent cuts as well as HSS, such as taking the corners off a square bar in a lathe.
What mechanisim controls pitch and roll on a plane?
(1) Control Stick - Pull back and push forward will input control to the Elevator that will raise the nose and drop the nose of the a/c. Move stick to Left and Right will input roll commands to the ailerons on the wing-tips. (2) Control Wheel - Pull wheel out and puch in will input pitch control. Rotate wheel clockwise and counter-clockwise will input roll command to the ailerons.
How to Find the Best Construction Machinery?
One can find more information about construction machinery by looking through books devoted to this subject. They can be found at a local library. One can also visit various sites on the web to find more information as well.
Why can't you attach a jet engine to a helicopter with similar results?
Question is not very clear. Most modern Helicopters are powered by turbo-jet engines that drive a transmission gearbox to turn the rotor blades. Jet engines have been attached to the tips of the main rotor blades. This design was used to turn the blades faster and have a smaller engine and gearbox. The forward velocity of a typical helicopter is limited by the tip speed of the rotor blades. The tip speed of the advancing blade is the sum of the airspeed of the helicopter and the speed of the blade. That is why helicopters are limited to ~150mph. If a jet engine was installed to push it faster, then either -A- the rotor blade would hit the sound barrier and become unstable or -B- the rotor blade would have to be stopped and the helicopter would have to fly using lift from a wing.
What is the reason for a maximum rotor RPM with power on in a helicopter?
Flying a helicopter is a delicate balance of Rotor RPM and Rotor Torque. Too little RPM and it would lose lift. Too much RPM, then the centrifugal forces could damage the rotor blades. When the pilot adds Collective input to climb, the Rotor Torque could be exceeded and result in failure of the mast. Each flight restriction was based upon the design of the helicopter's mast, blades and grip. Also, if the RPMs are too high the tips of the blade will hit the sound barrier and vibrate out of control. A helicopter with a blade length of 30 ft (radius) will only have to be spinning at around 330 RPMs to reach the sound barrier.
How does a helicopter fly?
A helicopter is able to fly because of the lifting effect of its main rotor. The rotor blades of a helicopter act in the same manner as the wings of a plane, creating lift by forcing air above and below a curved airfoil. The air moves faster over the top of the blade, reducing the pressure there. The air below pushes upward with greater pressure, lifting the rotor and the attached frame and cabin. At the same time, the blades can be angled in any direction, allowing it to move in any direction by using the blades like the propellers on an airplane. Jet helicopters also generate some forward speed from their turbine exhaust. The main rotor is the set of blades on the top of the craft, driven by the engine (piston, jet turbine, etc.). By turning the blades, which are airfoils and like a narrow "wing" in shape, we move them through the air. And by "tipping" the leading edge of the blade up (increasing the pitch) as it moves, the blade will have a positive angle of attack. It will bite into the air and force that air down. This forces the blades up, and the rotor will provide lift. Lift causes the craft to defy gravity. The torque (rotational motion) of a single rotor blade will have to be offset, and the tail rotor does this. Additionally, the tail rotor (or air turbine in the NOTAR helicopter) will also allow the craft to be turned and "pointed" in another direction. The pedals control the tail rotor or air turbine. By pushing the stick to the side (and adding a bit more pitch with the cyclic), the blades can be controlled to allow a bit more lift on one side to tip or bank the chopper and turn it. (A bit more pitch is added to offset the slight loss of lift.) The pedals will also be used in conjunction with the stick. By pushing the stick left, the blades will have a bit more pitch as they come around on the right side and a bit less as they come around on the left side. This will bank and turn the helicopter. Pushing the stick forward causes more pitch to the blades as they come around the back of the circle they make around the craft. This lifts the back of the craft. And it will make for a bit less pitch in the front for a bit less lift in front. This tips the craft forward. Often when we see a helicopter take off, it rises a bit, tips forward (now that the rotors will clear the ground), and accelerates forward as it continues to rise. The pilot has pulled up on the collective (to increase the pitch of the main rotor blades). That provided lift. He also has to push forward on the cyclic to tip the helicopter forward to begin to gather forward airspeed. (for more information see the related links below) A helicopter can take off and land vertically (straight up and down). It can fly in any direction, even sideways and backwards. It can also hover or hang in the air above a given place. A helicopter gets its power from rotors or blades. When its rotors are spinning, a helicopter doesn't look much like an airplane. But the rotor blades have an airfoil shape like the wings of an airplane. So as the rotors turn, air flows more quickly over the tops of the blades than it does below. This creates enough lift for flight. Additionally, helicopters avoid areas close to storms. The reason is that the helicopter requires a careful balance of the air supporting it. Downdrafts or turbulent winds can drastically affect control of the helicopter.
Why do helicopters fly so slow?
What is the limiting factor for helicopter speed you ask? What happens to the rotor as the velocity of the helicopter increases? The relative speed of the tips of the rotors changes because of the wind speed. On the advancing side of the rotor the speed increases by the speed of the helicopter. On the retreating side of the rotor the speed decreases by the speed of the rotor. One of two things happens as the helicopter reaches a high speed: A: If it is a large rotor, the advancing blade will reach the sound barrier and sap energy from the rotor, slowing it. Significant damage may occur to the helicopter. B: If it is a smaller rotor, the retreating blade will slow to the point where stall occurs, and the helicopter will be forced into a turn while losing altitude and decreasing speed, then it will usually recover if altitude permits. Option B can be mitigated by increasing rotor RPM at higher speeds. In this case the rotor speed becomes the limiting factor, as the centrifugal forces at the root of the blade are quite incredible. Carter
What makes a helicopter spin?
It's Fuel and Blades.How helicopters fly and are controlledHelicopters truly are amazing aircraft, and how helicopters fly is what makes them such versatile machines, being perfectly suited to roles ranging from military use to fire fighting and search and rescue.Helicopters have been around for centuries - well, the principle anyway - but it was Russian aircraft pioneer Igor Sikorskywho designed, built and in 1939 flew the first fully controllable single rotor / tail rotor helicopter - the fundamental concept that would shape all future helicopters.Why helicopters are so versatileA normal airplane can fly forward, up, down, left and right. A helicopter can do all this plus has the ability to fly backwards, rotate 360 degrees on the spot and hover ie stay airborne with no directional movement at all. Helicopters may be limited in their speed, but the incredible maneuverability mentioned above is what makes them so useful in so many situations.Above, the directions a helicopter can move in and the associated name of controlControlling a helicopterHelicopters require a completely different method of control than airplanes and are much harder to master. Flying a helicopter requires constant concentration by the pilot, and a near-continuous flow of control corrections. A conventional helicopter has its main rotor above the fuselage which consists of 2 or more rotor blades extending out from a central rotor head, or hub, assembly.The primary component is the swash plate, located at the base of the rotor head. This swash plate consists of one non-revolving disc and one revolving disc mounted directly on top. The swash plate is connected to the cockpit control sticks and can be made to tilt in any direction, according to the cyclic stick movement made by the pilot, or moved up and down according to the collective lever movement.But first, to explain how the main rotor blades are moved by the pilot to control the movement of the helicopter, we need to understand pitch...The basics of pitchEach rotor blade has an airfoil profile similar to that of an airplane wing, and as the blades rotate through the air they generate lift in exactly the same way as an airplane wing does [read about that here]. The amount of lift generated is determined by the pitch angle (and speed) of each rotor blade as it moves through the air. Pitch angle is known as the Angle of Attack when the rotors are in motion, as shown below:This pitch angle of the blades is controlled in two ways - collective andcyclic....Collective controlThe collective control is made by moving a lever that rises up from the cockpit floor to the left of the pilot's seat, which in turn raises or lowers the swash plate on the main rotor shaft, without tilting it.This lever only moves up and down and corresponds directly to the desired movement of the helicopter; lifting the lever will result in the helicopter rising while lowering it will cause the helicopter to sink. At the end of the collective lever is the throttle control, explained further down the page.As the swash plate rises or falls, so it changes the pitch of all rotor blades at the same time and to the same degree. Because all blades are changing pitch together, or 'collectively', the change in lift remains constant throughout every full rotation of the blades. Therefore, there is no tendency for the helicopter to move in any direction other than straight up or down.The illustrations below show the effect of raising the collective control on the swash plate and rotor blades. The connecting rods run from the swash plate to the leading edge of the rotor blades; as the plate rises or falls, so all blades are tilted exactly the same way and amount.Of course, real rotor head systems are far more complicated than this picture shows, but the basics are the same.Cyclic controlThe cyclic control is made by moving the control stick that rises up from the cockpit floor between the pilot's knees, and can be moved in all directions other than up and down.Like the collective control, these cyclic stick movements correspond to the directional movement of the helicopter; moving the cyclic stick forward makes the helicopter fly forwards while bringing the stick back slows the helicopter and even makes it fly backwards. Moving the stick to the left or right makes the helicopter roll and turn in these directions.The cyclic control works by tilting the swash plate and increasing the pitch angle of a rotor blade at a given point in the rotation, while decreasing the angle when the blade has spun through 180 degrees.As the pitch angle changes, so the lift generated by each blade changes and as a result the helicopter becomes 'unbalanced' and so tips towards whichever side is experiencing the lesser amount of lift.The illustrations below show the effect of cyclic controlon the swash plate and rotor blades. As the swash plate is tilted, the opposing rods move in opposite directions. The position of the rods - and hence the pitch of the individual blades - is different at any given point of rotation, thus generating different amounts of lift around the rotor disc.To understand cyclic control another way is to picture the rotor disc, which is the imaginary circle above the helicopter created by the spinning blades, and to imagine a plate sat flat on top of the cyclic stick. As the stick is leaned over in any direction, so the angle of the plate changes very slightly. This change of angle corresponds directly to what is happening to the rotor disc at the same time ie the side of the plate that is higher represents the side of the rotor disc generating more lift.Above, the layout of helicopter controls in relation to the pilot's seatRotational (yaw) controlAt the very rear of the helicopter's tail boom is thetail rotor - a vertically mounted blade very similar to a conventional airplane propeller. This tail rotor is used to control the yaw, or rotation, of the helicopter (iewhich way the nose is pointing) and to explain this we first need to understand torque.Torque is a natural force that causes rotational movement, and in a helicopter it is caused by the spinning main rotor blades; when the blades are spinning then the natural reaction to that is for the fuselage of the helicopter to start spinning in theopposite direction to the rotors. If this torque isn't controlled, the helicopter would just spin round hopelessly!So to beat the reaction of the torque, the tail rotor is used and is connected by rods and gears to the main rotor so that it turns whenever the main rotor is spinning.As the tail rotor spins it generates thrust in exactly the same way as an airplane propeller does. This sideways thrust prevents the helicopter fuselage from trying to spin against the main rotor, and the pitch angle of the tail rotor blades can be changed by the pilot to control the amount of thrust produced.Increasing the pitch angle of the tail rotor blades will increase the thrust, which in turn will push the helicopter round in the same direction as the main rotor blades. Decreasing the pitch angle decreases the amount of thrust and so the natural torque takes over, letting the helicopter rotate in the opposite direction to the main rotors.The pilot controls the pitch angle of the tail rotor blades by two pedals at his feet, in exactly the same way as the rudder movement is controlled in an airplane.NOTAR is an alternative method of yaw control on some helicopters - instead of a tail rotor to generate thrust, compressed air is blown out of the tail boom through moveable slots. These slots are controlled by the pilot's pedals in the same way as a tail rotor is. To generate more thrust, the slots are opened to let out more air, and vice versa.NOTAR helicopters respond to yaw control in exactly the same way as tail rotor models and have a big safety advantage - tail rotors can be very hazardous while operating on or close to the ground and in flight a failing tail rotor will almost always result in a crash.Throttle controlThe throttle control is a 'twist-grip' on the end of the collective lever and is linked directly to the movement of the lever so that engine RPM is always correct at any given collective setting. Because the cyclic and collective pitch control determines the movement of the helicopter, the engine RPM does not need to be adjusted like an airplane engine does. So during normal flying, constant engine speed (RPM) is maintained and the pilot only needs to 'fine tune' the throttle settings when necessary.There is, however, a direct correlation between engine power and yaw control in a helicopter - faster spinning main rotor blades generate more torque, so greater pitch is needed in the tail rotor blades to generate more thrust.It's worth noting that each separate control of a helicopter is easy to understand and operate; the difficulty comes in using all controls together, where the co-ordination has to be perfect! Moving one control drastically effects the other controls, and so they too have to be moved to compensate.This continuous correction of all controls together is what makes flying a helicopter so intense. Indeed, as a helicopter pilot once said... "You don't fly a helicopter, you just stop it from crashing"!
What is the fastest speed a windmill has gone?
The tips of the blades move the fastest. The 50 meter long (radius) blades of a 2 MW turbine rotate at about 14 rpm when the wind is 8 m/s; the tips of the blades are then moving at about 75 m/s.
What is the name of the helicopter with two propellers used to carry supplies?
Undetermined. All helicopters have 2 rotors; usually a Main Rotor and a Tail Rotor. So, I assume you meant 2 Main Rotors of same diameter.Boeing Ch-47 Chinook - One rotor mounted in the front over the cockpit and one rotor in the rear.V-22 Osprey - Both rotors are mounted on engine pods mounted at the tips of the wings. The engines rotate from helicopter mode to airplane mode. This helicopter just went into operational service after years of development.There are helicopters with no tail rotor. It has two rotors on top. One going clockwise the other going counter clockwise. Called Coaxial rotors or co-rotors are a pair of helicopter rotors mounted one above the other on concentric shafts. The military ones look like jets so even with jet engines. Very nasty looking helicopters.They are much faster and can turn and maneuver much faster. You can look it up. Helicopters with Coaxial rotors. I do not mean the ones with the fan in the tail. These just have wings on the tail.The other one is the NOTAR is the name of a helicopter anti-torque system which replaces the use of a tail rotor. Developed by McDonnell Douglas Helicopter Systems (through their acquisition of Hughes Helicopters), the name is an acronym derived from the phrase no tail rotor but uses air to keep the copter from spinning.
What is the world record speed attained in a helicopter?
Lynx - The World's Fastest Helicopter 20 Years On 11/08/2006 The 11th August marks the 20th anniversary of the Westland Lynx helicopter setting a new world helicopter speed record of 249.1 mph (400.87 kph). Although other attempts have been made, 20 years on Lynx retains the title as the world's fastest helicopter.
How fast can the apache hellicopter go?
Most typical helicopters can only go about 150mph or maybe a little faster. Compound helicopters or the V-22 Tilt-Rotor can fly at over 200mph or even 300mph. The maximum airspeed of a helicopter is limited by the speed of the rotor blade. The speed of the tip of the blade can not go faster than the speed of sound or it will go through the sound barrier and start to form 'shock waves' which can lead to vibration.This can be alleviated somewhat by changing the angle of the leading edge on the tip so it sweeps back. This has been introduced on several helicopters such as the Apache, Black Hawk and Lynx. The rotor blade turns about 50-60 revolutions per second although this is largely dependent on the length of the blade. The further out from the centre, the faster the rotational velocity and the faster the air is flowing over the blade. As the helicopter moves forward through the air, the velocity of the air over the advancing blades is the sum of the Forward Velocity Plus the rotational speed of the blade. Retarding blades do not suffer this problem as the airspeed at the tips is reduced, by virtue of the fact that the blades are travelling in the same direction as the airflow caused by flight. For example: Suppose the speed of Rotor Blade tip (helo in a hover) = 350mph. Speed of the Helicopter in flight = 150mph. Speed of Advancing Blade (in flight) = 350 + 150 = 500mph This simple calculation will determine the maximum speed of the helicopter. The two coast guard helos I am familiar with are the old HH3-HF Pelican that had a V-Max forward airspeed of 142knots and the HH60 Jayhawk that is rated about 165
Where is it possible to buy broadhead tips for arrows?
Lancaster Archery is an online shop that specializes in archery equipment and accessories. They sell broadhead tips, game points and replacement blades.
What mineral is used on drills saw blades and knife sh arpeners?
There are all different types, carbite tips to diamonds
Where can some free fast weight loss tips be found?
Free fast weight loss tips can be found in a wide variety of places. Common places to find weight loss tips would be online fitness programs. Weight loss tips can also be found at certain gyms.
