Whether you’re a professional or a newbie it always gets confusing to choose a motor. Especially, if you’ve to choose for a specific operation like crawling.
So, which one is appropriate between a sensored or sensorless for crawling?
A sensored motor is more appropriate for crawling than a sensorless motor. However, a sensored motor might be very prone to damages because of its intricate wiring. Moreover, it’s quite expensive compared to the sensorless one. But crawling requires high rpm and a sensored motor helps with that.
We’ve pictured different traits from numerous standpoints only for you. And we have all the questions you might have in mind answered down below. So, hurry up, join in!
Sensored and sensorless brushless motors have their own significant differences. Both of the motors come with quite a few advantages and disadvantages. Let’s have a glimpse of them:
|Sensored Motors||Great acceleration right down from zero rpm|
The operation is gonna be smooth, consistent, and predictable
A tremendous amount of torque at lower rpm
Very useful for data logging e.g. temperature, error in the motor
|Only good for RC truck and car|
More intricate structure than sensorless motor
|Sensorless Motors||Performs very good at high speed|
Not heavy, minimal weight
It doesn’t have a wire loom that gets damaged easily.
|Can stutter at the startup acceleration.|
Not relevant for applications with hefty loads
Doesn’t work adequately at low speed
Now, these were just the basic pros and cons of these two. We have a more in-depth head-to-head comparison between the two down below.
Let’s jump into it!
What is the Difference between Sensored and Sensorless Motors?
The main difference between sensored and sensorless motors is the hall effect sensor. Sensored motors use sensor wire plugged in the ESC.
On the other hand, a sensorless motor doesn’t have any link with the ESC. It uses a sensorless ESC to generate magnetic fields. That’s why you should know whether or not you can use it with sensored ESCs.
Let’s get an idea about what does sensorless ESC mean?
A sensorless ESC doesn’t use any sensor to detect the position of the rotor. It records the rotor direction by simply sending power to the engine. Therefore, it gives back the ESC a voltage signal. Basically, the motor creates back EMF which notifies the ESC about rotor position. Sensorless ESC works best at high speed.
Conversely, a sensored ESC already knows the rotor condition because of the built-in sensors. Therefore, the power signals that ESC sends to the motor are perfectly timed.
Now, the advantage of this is the enhanced productivity right from the zero RPM. That’s why you can feel the smooth throttle control without any stutter.
Let’s compare the two motors from various standpoints to have a better understanding.
How Does the Motor Work?
Sensored and sensorless motors operate in different ways. That’s why you can notice some benefits and drawbacks in both of the motors’ performance.
Along with the three inner cables, a sensored motor also includes a multi-wire loom. This helps to connect the power core of the speed to the engine. You’ll be able to locate these sensors on the edge of the loom.
So a sensored brushless motor is just a brushless engine with hall effect sensors. These sensors notify the engine regulator or ESC about the rotor’s exact direction. Hence, the system is extremely helpful to direct the startup cycle for the engine.
Also, the sensored motors function in a closed-loop system. Thus, there is no delay in synchronization. This can help your crawler to start without any stutter at low speed.
A sensorless brushless motor, on the other hand, doesn’t have hall effect sensors. Then, how do sensorless brushless motors work?
A sensorless brushless motor works by using the back-EMF. It’s the voltage generated by the engine. Using this it can quickly detect the rotor position and accordingly the speed. Sensorless brushless motors regulate in open-loop as their basic functioning system.
Winner: Sensored motors are more efficient motor work-wise.
How Durable is it?
If you’re getting a motor for your crawler then you better get a solid one. Let’s find out which one is more durable between sensored and sensorless.
Now, a sensored motor has quite an efficient motor system. However, the sensors that make it great aren’t waterproof. This makes it vulnerable to rough terrains, or excessive bumps. Hence, there’s a chance the sensors might get damaged or disconnected.
So if you’re planning to ride it in a wet or rugged environment, you might’ve to rethink. This is because the sensors wouldn’t last very long.
Conversely, a sensorless brushless crawler motor is more durable than a sensored. As it doesn’t carry any fragile wire loom therefore it’s less prone to damage. Also, they don’t have sensors that’s why there won’t be many issues in a damp setting.
Hence no matter the location, you can use your sensorless motors without a problem!
Winner: Sensorless motors are more durable than sensored motors.
How Effective is the Motor Under Different Conditions?
Sensored and sensorless brushless motors vary in performance in different circumstances. Let’s find out how!
Sensored brushless motor waterproof, from the previous section we can recall that it’s not. Although that might hinder the performance a bit, the torque makes up for it.
Sensored motors develop torque at very low speeds. For this reason, they’re very useful for rock crawling or any other slow-speed RC vehicle. Hence, the startup acceleration of your crawler will be very smooth with sensored motors.
Moreover, there won’t be any cogging. Plus, it’ll even run smoothly under stress or less battery power or heavy load.
On the other hand, sensorless brushless motor cogging is very noticeable at low speeds. Because the back EMF generation is very weak at slow speeds during on-road use. Therefore, starting up a sensorless motor can be quite difficult.
Now the sensorless motor’s open-loop system is more durable at higher speeds. But due to the unsuitable motor, it’s not preferable to use it for crawling applications.
Winner: Here we’re favoring the sensored motor. Because low speed, high torque would be more appropriate for your crawler.
Does it Require Ventilation or Cooling System?
Motors are inclined to get too heated if overused. Sometimes wrong gearing of wiring can result in accidents because of extreme heat. That’s why you need your motor to have a proper ventilation system.
Here we’ve mentioned how the cooling system works in sensored and sensorless motors.
Sensored brushless motor wiring is relatively complex. Because it has additional wires than a normal motor. Thus there’s likely to be enough contact resistance and heat generation. So it would require a decent cooling system.
To properly ventilate the system, you need to use a heat gun. This will help to leak the stream of hot air from the motor. Here’s a list of heat gun recommendations only for you.
Sensored motors normally have a compartment or hole open up for airing. Moreover, the motors have an efficient data logging system. The sensor wire helps to transmit the temperature value to the ESC as well.
Therefore, if your crawler gets too hot it’ll stop operating. The motor will cool down by releasing the hot air and preventing any sort of damage. Once it’s cool, it’ll start operating again.
A sensorless motor generally doesn’t have any heat generation problems. Because there’s no wire loom or sensor wires, therefore, no friction or resistance. As a result, sensorless motors don’t require open space or ventilation like sensored motors.
Winner: Here we’re selecting the sensored motor because of its advanced data logging system.
How Good Can it Work with the ESC?
An electronic speed controller or the ESC is a very crucial component of a motor. So it really matters how compatible your motor is with the ESC.
Normally a sensored motor works best with a sensored ESC. But what if your vehicle doesn’t require high torque, such as a helicopter or a drone.
In that case, can you run a sensored motor sensorless?
Yes, you can run a sensored motor on a sensorless ESC without any issue. In this case, the ESC will detect the rotor position depending on the back EMF. Hence, your sensored motor will function as a sensorless motor. Because the sensor wire won’t be plugged in with the ESC.
In short, the sensored motor is compatible with both sensored and sensorless ESC. However, if your ESC has beeping problems, then it might not work like that.
Now, are you asking, if you can use a sensored ESC in a sensorless motor?
In reality, a sensored ESC doesn’t run properly in a sensorless motor. You need to configure the motor appropriately to run it.
Winner: The sensored motor is more compatible with different ESCs hence preferred.
How Difficult is the Maintenance?
The maintenance might not be too difficult for either of these. However, you need some maintenance to keep it functioning well.
When operating in muddy terrains, mud or dirt might reach the motor. In such a case, you’ll have to rinse it thoroughly. Moreover, a dry electronic cleaner aerosol might also help to clean it. Especially if it’s too dirty around the speed controller.
Moreover, a sensored motor has 3 hall sensor wires along with 3 phase wire leads. These are quite vulnerable to damage and might need constant soldering or repair.
The sensorless motor doesn’t have any additional wires hence less friction and heat. So, it’s normally closed up to prevent mud or little grains from getting in as there’s no ventilation needed.
But a sensorless motor stutters and cogs a lot. That’s why you need to inspect the wirings and gears time-to-time to fix the cogging. You can increase the power to your motor which will give it the additional kick to prevent cogging.
Winner: It’s a tie. As both sensored and sensorless brushless motors need some maintenance.
Which One is More Cost Efficient?
The price of a motor plays a key role in making a choice. So let’s see which one’s more budget-friendly.
The sensored brushless motor ESC combo is quite costly. The price usually ranges from $100 to $250. This might be because of the extra wires, sensors, and sensored controller it needs.
On the other hand, sensorless brushless motors are less expensive. These range from $20 to $70. The lower price might be due to the complex cable connections.
Winner: Sensorless motor is cost-friendly.
So, Which One is Better?
Here comes the final verdict. Is sensored or sensorless better?
A sensored motor is better for crawling because it needs a lot of speed control. Moreover, it enables the ESC to regulate the spin and speed of the engines accurately. Especially at low speed, it delivers a steady throttle sense.
So we would recommend you to get yourself a decent sensored motor for crawling.
Can you run a sensorless motor without an ESC?
No, you can’t run a sensorless motor without an ESC. Because without an ESC there would be no power supply to the motor. ESC identifies the rotor position based on back EMF in a sensorless motor. Then generates pulses to run and control the motor.
Can I operate a sensored motor without a sensor cable?
Yes, you can operate a sensored motor without a sensor cable. Your motor’s ESC will just operate as a sensorless ESC without the sensor wire plugged into it.
Can you grease a brushless motor?
Yes, you can grease a brushless motor. After some use the gearing shafts of the motor can get stiff. Using some grease or lubricant on them might fix the issue.
Hope now it’ll be easy for you to choose between sensored vs sensorless for crawling.
However, if you still have any doubts, here’s a bonus tip. Practically you can use either of these motors for crawling. But to know which might be the best, compare the Kv-ratings. Crawlers usually use low Kv-ratings. Now you know which one to choose!
Until next time, stay well!