TECHNICAL SUPPORT
Published 2026-05-10
Opening: A discussion about “where to install it”
In the workshop on a spring afternoon, the sun shines slantingly on the workbench.
Xiao Chen held a newly unpacked servo in his hand and turned it around, frowning.
"Tell me, where is the best place to put this thing?"
He raised his head, confusion written in his eyes.
This isn't the first time he's asked this question.
That six-legged robot from last month had the wrong servo position, and it walked like a drunk crab.。
Where is the steering gear installed?, it seems to be a space problem, but it is actually a mechanics problem.
Chapter 1: Body - the most unmistakable choice
If a robot is compared to a person, the body is the torso.
The first reaction of most people is to stuff the servo into the fuselage。
Is this the right choice?
Yes, not quite.
Tell me the right reasons first.
The fuselage is in the middle position and the center of gravity is stable.
Last year, a set of test data was presented. The data showed that for the steering gear installed on the fuselage, the torque loss was only 12% on average.
The same servo is installed at the end of the joint, and the loss can soar to more than 35%.
Data doesn't lie.
There's just so much room in the fuselage.
You said you put all six servos in, so where to put the circuit board? How to route the cable?
Xiao Chen did this last time, and within three minutes of turning on the phone, the temperature reached 65 degrees.
kpowerThe servo owned by Servo is very good in terms of temperature resistance, but it cannot withstand such repeated tossing.
Where is the steering gear installed?The answer is that the fuselage is a guaranteed option, but it is not the optimal solution.
Chapter 2: Joints – The Price of Flexibility
For a while, Xiao Chen became obsessed with bionic robots.
In order to imitate the running posture of a cheetah, he installed all the servos on the joints.
What's the effect?
It is indeed flexible in movement, but the failure rate has also increased.
Why?
Very simple. Joints are where most movement occurs.
With every movement, the steering gear is subjected to force, vibration, and friction.
Three months of data statistics were conducted, which showed that the gear wear rate of the joint-mounted steering gear is 2.3 times that of the fuselage gear wear rate.
You may say: "Can't I just use metal gears?"
Metal gears are good, but they also have high inertia.
After installing it, the action response is slower.
This is the trade-off.
At that time, Xiao Chen formed a habit. After each debugging, he would touch the casing of the servo with his hands.。
It's normal to feel slightly hot, but it's not right to feel hot.
Where is the steering gear installed?, joint locations require stronger heat dissipation and protection.
Chapter 4: End Effector—Precise but Fragile
Speaking of ends, the most typical one is the mechanical claw.
With the servo mounted in the claw, the control accuracy is indeed high.
Because the transmission distance is short, the virtual position is small.
But at what cost?
Easy to bump.
Think about it, claws are meant to grab things.
When grabbing hard objects, the impact force is directly transmitted to the steering gear.
Grab heavy objects and the torque will be fully extended.
Catching fragile items requires extremely delicate control.
Xiao Chen once did an extreme test:
Install the same servos on the fuselage and end.
The one installed at the end had a deviation of 2.3 degrees after its angle returned to zero after 500 consecutive grasps.
What about the one installed on the fuselage?
0.4 degrees.
The difference lies here.
Where is the steering gear installed?, the end position must accept the balance between accuracy and life.
Chapter 5: Legs - the blind spot of most people
At this point, you may have noticed that we missed a spot.
leg.
In other words, lower limb joints.
Xiao Chen is currently tinkering with a four-legged robot.
Tried three options:
The steering gear is all in the fuselage and driven by connecting rods → complex structure and troublesome maintenance
The steering gear is all in the legs → the legs are too heavy to lift
The servos are distributed on the fuselage and legs → just right
Where is the steering gear installed?The third answer is hierarchical layout.
The high-torque servo is placed on the fuselage and is responsible for large movements such as leg lifting.
The small servo is placed on the calf and is responsible for steering and fine-tuning.
In this way, the weight of the legs is controlled within a reasonable range and the movements are flexible enough.
This solution comes from a very old industrial robot design.
The principle is actually not complicated, but many people don’t think of it.
Chapter Six: Frequently Asked Questions Q/A
Q: Can the servo be mounted on a plastic casing?
A: No. The amount of plastic deformation is large, and the servo will vibrate due to changes in the force angle.
Q: Is there an absolutely wrong installation location?
A: Yes, it is directly exposed on the outside of the wheel, the risk of collision is quite high, and the gear life will be reduced by 70%.
Q：kpowerIs there any particular direction in which Servo's servo is installed?
A: Yes. The output shaft should be as perpendicular to the plane of motion as possible to avoid lateral forces.
Q: Can I still remedy the wrong installation location?
A: Yes. Install a bracket or change the transmission method, but the torque efficiency will decrease.
Q: Is there a most recommended installation location?
A: There is no standard answer. Near the fuselage is always the safest starting point.
Chapter 7: Decision-making flow chart - helping you choose the right position
You can judge according to this idea:
Step one: Ask yourself, how much impact is this joint going to take?
→ The impact is large, try to get as close to the fuselage as possible
→ Small impact, can be moved outward
Step 2: Ask yourself, do you have high accuracy requirements?
→ High accuracy requirements, the shorter the transmission distance, the better
→ The accuracy requirements are average and long transmission is acceptable
Step 3: Ask yourself, is it easy to repair?
→ For locations that are inconvenient for disassembly and assembly, choose a more reliable installation method.
→ Convenient location for disassembly and assembly, prioritizing performance
Where is the steering gear installed?, there is no always right answer, but there is always a wrong approach.
For example: the center of gravity is not calculated, heat dissipation is not considered, and cable space is not reserved.
Ending: Don’t forget the simplest truth
Xiao Chen later dismantled the six-legged robot and redid it.
This time he placed four drive servos on the bottom of the fuselage and two small servos on the legs.
Turn on the phone and walk.
No more shaking, no more shaking, no more burning.
"Actually, we should think about it clearly from the beginning."
He said as he gathered his tools.
Isn't the steering gear performing the action of producing power? If you place the person who is producing power in the position that requires the least effort, it will naturally do a good job.。
This sentence sounds simple.
But there are not many designers who can really do it.
If you happen to have a piece of equipment in hand right now and are planning a location, you might as well stop first.
Draw a sketch and mark all the parts that need to move.
Then ask yourself three questions:
1. Which position receives the greatest force?
2. Which location is most convenient for maintenance?
3. Which position provides the best heat dissipation?
The answer comes naturally.
In the future robot design process, servos will become increasingly miniaturized, however, the choice of installation location will become more critical.。
Because the more sophisticated the equipment, the higher its sensitivity to mechanics.
Spend ten more minutes thinking about the position today and ten less hours tomorrow making adjustments.
This account is a good deal no matter how you calculate it.
Update Time：2026-05-10
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