If You Don’t Understand The Steering Wheel, Your Choice Of Steering Wheel Will Be In Vain! Understand The Control Surface Of The Aircraft, And Choose The Steering Gear To Direct Where To Hit.

Have you ever encountered this situation? When doing product innovation, especially when it comes to equipment that requires precise angle control, the motor is obviously very large and powerful, but the movement is not smooth enough, or the response is always half a beat slow. When I first started tinkering withservoapplications, I was often stuck on this problem. Later I discovered that many times the problem was not with the steering gear itself, but with my insufficient understanding of the "control surface" of the aircraft. This thing sounds professional, but it is actually the "steering wheel" and "brake" of the aircraft. Once you understand it, you will have a good idea of how to choose theservoand adjust the parameters, and the finished product will be able to hit where you want it.

What exactly isthe control surface of an airplane ?

To put it bluntly,the control surface of the aircraftis just some movable "small plates" installed on the wings and tail. Just like a fish changes direction by swinging its fins, an airplane relies on the deflection of these rudder surfaces to change the direction of the airflow, thereby generating different forces that allow the airplane to complete climbs and turns. For those of us who make products, the rudder surface can be understood as the "load" that the steering gear is to push. Its area size and the position of the rotation axis directly determine how much force the steering gear needs to exert and how fast it turns. Many people ignore this point. As a result, the steering gear torque is selected to be small, and the steering surface cannot be pushed; or if it is selected to be large, it not only wastes power, but also makes the movement look clumsy.

Why is it important to understand the rudder when choosing a steering gear?

It's like choosing the right hinges for a door. You need to know how heavy and large the door is before you can choose a hinge that can hold the door firmly without being too bulky. The same is true for the relationship between the rudder surface and the steering gear. For example, if you want to make a flapping mechanism of a bionic bird, its "wings" are a complex rudder system. If the wings themselves are heavy and the windward area is large, but you choose a micro-servo, the result will definitely be that it will not be able to fly, or even the servo will be burned directly. Therefore, understanding the working principle of the steering wheel can in turn help you accurately calculate the torque requirements of the steering gear and avoid the embarrassment of "a small horse pulling a big cart" or "a cannon hitting mosquitoes".

How to tell which surface control your product needs

You can work backwards from the product’s action requirements. Ask yourself a few questions first:

️Isthis movement large?For example, if your product only needs to make minor direction corrections, the deflection angle of the rudder surface will be small; if it is to maneuver in a wide range, the rudder surface will need to deflect at a large angle.

️Areyou moving quickly?Is it an instant flip like a 3D model airplane stunt, or is it a slow adjustment like a pod under a weather monitoring balloon?

️Isthe stress environment no longer complex?Is it in still air or in high-speed flowing air?

After thinking through these questions, you can determine the type of helm you need. Is it a simple and straightforward aileron, or an elevator that requires more power? This determines your focus when choosing a servo, whether it is accuracy, speed, or strength.

Common rudder surface types and their application scenarios

We mainly come into contact with three types when getting started:

1. Ailerons: Installed on the trailing edge of the wing, with differential deflection on both sides, one upward and one downward, the aircraft will "roll" shyly like a girl seeing a handsome guy.

2. Elevator: On the trailing edge of the horizontal tail, move upward or downward together to control the aircraft to "raise" or "lower".

3. Rudder: on the trailing edge of the vertical tail, deflect left and right to control the "shaking" of the aircraft.

In your product, for example, make an artificial intelligence-controlled photography gimbal. Although it does not have wings, the action logic of pitching and rotating is equivalent to imitating the control of elevators and rudders. Once you understand these, you can skillfully transplant mature aviation control logic to your innovative products.

The rigid requirements for the steering gear stroke due to the deflection angle of the rudder surface

This is a very real matching problem. Each servo has its maximum rotation angle, such as 90 degrees, 120 degrees, and 180 degrees. When designing the aircraft's rudder surface, it also has a most efficient deflection range. For example, it is generally enough for the upper and lower ailerons to deflect 20-30 degrees each. If the servo stroke is much larger than the required angle of the rudder surface, you have to set a rudder limit in the remote control or flight controller, otherwise the rudder surface may be "stuck" at the extreme position, causing the servo to remain blocked and easily burn out. On the other hand, if the servo travel is insufficient, the aircraft will not be able to achieve the maximum designed performance. Therefore, this linkage relationship must be calculated during design.

The invisible impact of rudder surface hinge torque on steering gear life

This is a detail that many novice friends tend to overlook. The place where the rudder surface rotates is called the "hinge". When the air flows through the rudder surface at high speed, it will generate a force that tries to blow the rudder surface back to the neutral position. This is the hinge torque. The task of the steering gear is to overcome this torque and firmly fix the rudder surface at the designated position.

If the hinge is not designed smoothly, or the rudder surface is not dynamically balanced, the torque will fluctuate, causing the servo to constantly correct back and forth, resulting in "rudder shake". If this continues, the potentiometer inside the servo will wear out and the motor will become fatigued. Just like someone keeps asking you to raise your arms and not move them, your arms will definitely be sore and trembling after a long time. Therefore, making your steering surface rotate smoothly enough is the best protection for your steering gear.

Now that you understand the inextricable connections between aircraft control surfaces and servos, do you feel that your thinking will be much clearer when designing related products in the future? In actual projects, have you ever experienced a vehicle overturning due to improper matching between the steering surface and the steering gear? Welcome to share your story in the comment area. Let’s avoid pitfalls together. If you find the article useful, don’t forget to like it and share it with more friends who need it!