RC cars are not everyone’s thing – especially those who would rather drive slow and steady. Those who prefer racing over a slow drive, fuel their spirits with speed and thrill. Therefore, today we will be discussing a high-performing RC car motor – Castle 1721 2400Kv.
The 1721-2400Kv motor is exclusively for those who get want to upscale their RC racing game.
But do you know what makes the Castle 1721 2400Kv the fastest RC car motor?
If not, in this article we will be discussing, step-by-step, the features of the Castle 1721 2400Kv motor.
Castle 1721 2400Kv comes without a warranty
Every electronic product bought online comes with literature, just like with the Castle 1721 2400Kv motor. The product usage warning is helpful in knowing how to use that item and warns you of damaging the item. This is the case for most items, however, in the case of this Castle 1721 2400Kv motor, the warning states that there is no warranty with this product due to the extreme nature of the motor.
This is the first alarming point.
In fact, it states that there is no warranty for ANY Castle electronics, including the ESC when used with this motor – that’s how powerful it is.
Even if we connect this motor to any random battery back, it may also not have a warranty.
Why, though? Well, for that you can go over the product warning literature that comes with the Castle 1721 motor. But take this is as the first sign as to why this motor is ridiculously insane and fast. The fact that it’s such a beast of a motor, maybe it does not even need a warranty?
Now, let’s talk about the actual first point as to why this motor is so insanely fast.
Size Comparison of the Castle 1721 2400Kv
The Castle 1721 2400Kv motor is designed for radio control cars of the 1/8 or 1/7 scale. If we compare this motor with another motor of the same scale, there is a very noticeable difference in size. The Castle 1721 motor is not only double the size of the motor that we compared within our YouTube video. (Castle 1512 2650Kv) But it can be the perfect 4s-8s motor for any RC 1/8 scale RC.
Apart from the length, we noticed that Castle 1721 has a larger diameter than the other motor. Though this may not seem like rocket science for most RC enthusiasts, it is important when discussing the power-packed performance of the Castle 1721 2400Kv motor.
Moving on, the following two features of this RC car motor are worth mentioning.
These two features are what set the Castle 1721 motor apart from its competitors. We did a little comparison, which can be seen in the YouTube video here.
Comparing RC Car Motors
Since we have no warranty on the Castle 1721 motor, we disassembled it and revealing the inner workings. You can check out the full video of disassembling it here.
Once the screws are off the front cover, we pulled the rotor out of the motor, exposing the insides.
It is noticeable here that the screws don’t go into the body of the motor to help center the shaft similar to the 1512 motor. It is the end caps embossed feature that pushes in to the motor can to center the shaft. Then the screws just make sure nothing comes apart.
Next, we pulled out the rotor from the brushless motor, and this is where we noticed a significant difference between the Castle 1721 2400Kv motor and the other one. Keep in mind, the motors must be placed at a distance apart to prevent them from snapping into each other as there is a strong magnetic force.
Stainless Steel Sleeve
With the 1512 and 1721 motor now apart, we noticed the kevlar wrap on the 1512 motor. You can see the wrap around the rotor of the motor. This is what indeed makes the rotor hold its contents intact. Without the Kevlar wrap around the motor, the magnets, after speeding up, would have destroyed the motor.
In fact, the Kevlar wrap limits the motor to 60,000 RPM, approximately the size of the smaller motor that we used for comparison. This is why the Castle 1721 motor is different – there is no Kevlar wrap around its magnets and you probably cannot even tell if the magnets are there or not.
The Castle 1721 motor has a stainless-steel sleeve inside that encapsulates the magnets and prevents them from flying out of the rotor’s core. The stainless steel sleeves help in increasing the holding strength of magnets and prevent them from ejecting from the rotor. This way the motor reaches up to 90,000 RPM, making the Castle 1721 a high-performing motor.
Now let’s discuss the final feature that makes the Castle 1721 a ridiculously awesome motor.
Windings inside the RC Car Motor
Although the structure of windings is not visible inside the RC car motor, we know that Castle markets this motor as a 0.5Y wound motor, and that is a very significant feature.
This significance lies in the fact that typical Castle motors of the 1/8 scale or larger have all been 1Y wound brushless motors. The wind is what allows the user to maximize the total amount of RPM in the RC vehicles.
To explain this phenomenon even further, let’s develop a hypothetical situation. Suppose that this Castle 1721 motor was actually being sold as a 1Y wound motor, what would that imply?
Knowing that the 0.5Y is actually 2400Kv, a 1Y is going to be 1200Kv. So, in order for us to maximize on the total amount of RPM, 8s, the maximum voltage that this motor can work very well with, won’t be enough for the 1200Kv motor to make use of the 60,000 to 90,000 RPM range.
To actually do that, we would have to go to 16s, instead of 8s, which is not very practical. Therefore, it is more convenient to use 8s. As for our 0.5Y wound motor, since we do not need to double voltage what we get in return is the potential to double current! This means we can run 8s voltage but pull easily double the current that any other 17 series motor can handle. Think about that for a moment!
Once you go below one turn, the winding essentially becomes a competition type wind. This really just means they produce a lot of power by utilizing a ton of current. This is why you get a warning label with the motor, making sure you know what you’re doing with the motor.
Final Thoughts
That’s it for the different kinds of warnings on the Castle 1721 2400Kv motor and why we don’t have a warranty with any castle products. This motor is an absolute Beast. Don’t be surprised if this motor pulls over 500A under heavy acceleration on 8s. It is very well capable of these power levels. (>15hp) That’s what makes this motor such a beast of a motor.