RC Helicopter Gyro Explained

RC Helicopter Gyro Explained - Part 2

Now that we know what a gyro is (from the previous post) lets see how it applies to RC helicopters.

Why does a helicopter need a gyro? The answer is - for stability.

As you might know, in a helicopter the main rotor generates both the lift and the trust. Therefore the engine (or the main motor) has to provide a lot of torque to the rotor. Unfortunately, this torque not only spins the rotor but also spins the fuselage of the helicopter in the opposite direction. That's why a helicopter needs a Tail Rotor or a similar 'anti-torque' mechanism to cancel out the torque on the fuselage.

To keep the helicopter stable the anti-torque mechanism must respond quickly to any changes in torque. But the problem is, the torque is always changing. Changes in the engine or motor speed, changing the pitch of the rotor or even gusts of wind change the torque and will try to spin the helicopter out of control. In a RC helicopter, manually adjusting the tail rotor for these constant changes would be next to impossible. The helicopter gyro takes care of this by detecting any yaw movement (swinging movement) and sending the commands to the tail rotor (or any other anti-torque mechanism) to compensate for it.

What are RC gyros made of?

In the early days, RC helicopters also used mechanical type gyros. These consist of two flywheels spun by a small motor. This setup was mounted on a pivot and a magnetic sensor detects any movement of the wheels happen because of the movements of the helicopter.

A mechanical gyro used in old RC helicopters

The newer RC models use piezoelectric gyros, which has several advantages over the mechanical ones. Reduced size, weight and battery consumption and improved accuracy have made the piezo-gyro the choice for the newer models.

A piezoelectric gyro used in newer RC models

Gyros are also divided in to two categories by how they respond to yaw movements - Yaw Rate Gyros and Heading Hold Gyros. I'll talk about them in the next post.

References
http://en.wikipedia.org/wiki/Helicopter
http://en.wikipedia.org/wiki/Radio-controlled_helicopter
http://en.wikipedia.org/wiki/Tail_rotor

Comments

Selecting the Correct Gauge Wires for your RC Models

When we are building RC models (aircrafts, multicopters etc.), something we typically overlook is what type of wires to use to distribute power in them. Usually, we try to reduce the weight of the model, so we tend to go with smaller wires. But, we cant expect to put in small circuit-wires and have them handle the amount of power needed. If you look at the wires that comes in the output leads of a Li-Po, or the wires that comes on a standard XT Jack, you'll notice that they're quite huge. Large gauge wires on a Li-Po and XT connectors These need to be huge to handle the amount of amperage that goes through them. So, we should also consider the amperage, and the length of wire needed when selecting the size (gauge) of the wires.

Make Your Own Jupmer Wires for Electronic Breadboard

Note: After starting the 'Tips and Tricks' section I wanted to do my own 'tutorial'. So, here's my first attempt of it. Hope you all find this useful, and sorry about the low quality of the photographs, my camera is just a 2MP. If you, like me, like to experiment with electronics, then you'd probably use an electronic breadboard (also known as protoboard or project-board). These allow you to construct and test circuits without the need to permanently soldering the components. The problem with these is that you have to use wires to connect the components across the bus lines. We normally use single core circuit wires for this purpose, but they tend to bend, break and get stuck in the breadboard when used repeatedly. This may cause short circuiting the bus lines and could be the failure of your circuit. A better option would be to buy a 'Breadboard Jumper Wire' kit, such as this. A Breadboard Jumper Wire Kit These have sets of wire of differ

What do the prop size numbers mean?

Have you been trying to shop for propellers - either online or at a hobby shop - and got confused of the numbering used to denote the size of the propellers? You see things like " 10 x 4.5 CW ", or " 8055 CCW ". What do these numbers mean? A 8 x 4.5 CW and CCW Propeller Set It's actually quite simple once you figure it out. The first number denotes the diameter of the prop (length from tip-to-tip). The second number denotes the pitch of the prop. Here, the pitch is denoted as a length, not a angle. Let's see how that works.

Code 42

Search This Blog