When we talk about 48mm DC gear motors, I see questions about speed all the time from our customers—especially engineers, product designers, and small business owners who are working on projects like automated conveyor systems, adjustable medical equipment, or robotics where that extra speed makes all the difference. As someone who’s been selling and supporting these motors for years, I get it: the 48mm size is such a sweet spot for power and compactness, but there’s no one-size-fits-all trick to cranking up the speed without breaking the motor or shortening its lifespan. Let’s walk through the practical, science-backed steps I’ve helped hundreds of customers test and implement, because that’s what really moves the needle—no guesswork here. 48mm DC Gear Motor
First, let’s start with the basics that a lot of people overlook when they’re in a hurry to get more speed. DC gear motors (our 48mm models included) run on a core principle where speed is tied directly to input voltage—within reason. The nameplate voltage on our motors is the recommended operational voltage, but it’s not an absolute hard limit. Wait, hold on before you jump to crank it up to 24V on a 12V motor: that’s a mistake. Our 48mm DC gear motors are designed with specific winding counts for their voltage rating to balance speed, torque, and heat. If you apply a voltage higher than the rated value, you increase the RPM of the motor, but you also ramp up current draw and internal heat exponentially. We tested this with our most popular 48mm 12V gear motor for a conveyor project a couple of years ago: when we bumped input voltage to 14V (20% over rated), the no-load speed jumped 22%, but under load, the internal temperature climbed 18°C within 10 minutes of operation. That extra heat will wear down the brushes, the gear grease, and the winding insulation way faster—usually cutting the motor’s lifespan in half. If you do adjust voltage, stick to a 10-15% overvoltage max for short, intermittent load, and always monitor temperature with a probe if you can. For continuous operation, though, this isn’t a long-term solution—you need to pair voltage adjustment with other changes.
Next, the gear ratio is the single biggest lever you can pull for speed, and it’s one where a lot of customers swap gears without understanding the tradeoffs. The gear ratio is the number of turns the motor shaft makes for every one turn of the output shaft. A higher ratio (like 100:1) is for more torque at lower speed, while a lower ratio (like 20:1) is for higher speed. Our 48mm gear motors are available in a range of standard ratios for exactly this reason, but some customers don’t realize that you can reconfigure the internal gear train if you have access to replacement gears (or source compatible ones from a reputable supplier—just make sure they’re precision-machined, not cast, to avoid wear). A customer working on a mobile robot platform came to us last year saying their 48mm gear motor was too slow to keep up with the robot’s drive system; they had a 50:1 ratio, so we suggested swapping to a 25:1 ratio. The output speed jumped exactly 100% (since the ratio was halved) without any change to the input voltage, and they kept the same torque they needed for climbing small ramps. The catch here: lower ratio means lower torque, so you have to make sure your application doesn’t need that extra torque. If you’re lifting something heavy or moving a load up an incline, you can’t just drop the ratio. That’s where balancing torque and speed comes in—we always work with customers to match the ratio to their exact load requirements first, then optimize from there.
Then there’s the motor’s no-load vs. loaded speed, which is a point of confusion for almost everyone. No-load speed is how fast the motor spins when there’s nothing attached to it, while loaded speed drops because of friction in the gears and wind resistance from the motor’s armature. To cut down on that friction (and boost loaded speed), you can improve the lubrication in the gear assembly. Most of our standard 48mm gear motors come with lithium-based grease, but if you switch to a high-performance synthetic grease designed for low friction and wide temperature ranges, you can reduce rotational drag by up to 10-15% in some cases. We tested this for a customer building a automatic door operator; their original motor was getting 120 RPM at no load but only 95 RPM when opening the door. After we re-greased the gear train with a synthetic PAO-based grease, the loaded speed jumped to 108 RPM, almost matching the no-load speed, without any voltage changes or ratio swaps. Just don’t over-grease it—too much grease adds extra drag, same as too little. A pea-sized amount for the gear compartment is all you need for our 48mm motors.
Another factor that’s often overlooked is the condition of the motor’s brushes and commutator. Brushes are the small carbon pieces that transfer power to the armature, and over time, they wear down, creating resistance. If your 48mm gear motor has been running for a while, worn brushes can drop speed by 5-10% or more. We recommend inspecting the brushes every 1,000 hours of operation. If they’re less than 1mm thick, replacing them will not only restore speed but also improve overall efficiency. For customers building long-life applications, we also offer upgraded graphite brushes for our 48mm motors that have 30% less resistance than standard carbon brushes—those can add a solid 8% speed boost without any other changes. If you have a brushless 48mm gear motor (we sell those too for high-cycle applications), you don’t have to worry about brush wear, but you do need to make sure the electronic speed controller (ESC) is calibrated correctly. A mis-calibrated ESC can limit the motor’s maximum speed by up to 15%—we’ve had a lot of customers fix slow motor issues just by re-calibrating their ESC according to the motor and ESC manufacturer’s specs. That’s a free fix that takes 5 minutes, so it’s always worth checking first before modifying the motor itself.
Wait, what about winding modifications? That’s a step reserved for more experienced users, and it’s not for everyone, but it’s a legitimate way to boost speed for specific projects. The armature winding in our 48mm DC gear motors is wound with a certain number of turns of wire, and the gauge of that wire is matched to the rated voltage. If you rewind the armature with fewer turns of thicker wire, you can increase the motor’s speed at the same input voltage—because fewer turns mean less back electromotive force (back EMF), which is the force that opposes the motor’s rotation at speed. But here’s the tradeoff: thicker wire has higher current capacity, so you’ll draw more current, which means you need a power supply that can handle the extra load. We’ve worked with a customer who was building a high-speed model train layout; they rewound the armature of our 48mm 12V motor to have 20% fewer turns with 15% thicker wire, and the speed jumped 30% at the same 12V input. But they had to upgrade their power supply from 5A to 8A to handle the higher current, and they had to make sure the gear train could handle the increased RPM (which it did, since it was a light load). Rewinding is not something we recommend for beginners, because if you do it wrong, you can burn out the motor winding, but for experienced engineers with the right equipment, it’s a solid method.
Now, let’s talk about what you should never do if you want to increase speed without shortening your motor’s life. First, don’t exceed the motor’s maximum rated voltage by more than 15% for continuous use. I mentioned this earlier, but it’s worth repeating: we’ve seen customers crank a 12V motor to 20V to get more speed, and within 2 hours, the winding insulation failed and the motor burned out. That’s a $50 motor gone to waste, all for a temporary speed boost. Second, don’t remove the gear assembly entirely—if you take the gears off, you’ll have the motor’s unloaded armature speed, which is way too fast for almost all applications, and you’ll lose all torque. Third, don’t use a higher voltage power supply that’s not regulated. Unregulated power supplies can deliver voltage spikes that damage the motor’s electronics (if it has an integrated controller) and the gears. Always use a regulated power supply that matches the motor’s rated voltage and current.
I also want to emphasize that all these steps are application-specific. A speed boost that works for a light, intermittent load (like a small robotics arm) might not work for a heavy, continuous load (like a conveyor belt moving 50kg materials). That’s why we always work with customers to first define their two non-negotiables: maximum required speed and minimum required torque. Once we have those numbers, we can pick the best combination of ratio, voltage adjustment, lubrication, and brush condition to get exactly what they need. For example, if a customer needs 150 RPM at 5Nm of torque, we might recommend a 25:1 ratio, synthetic grease, and a calibrated ESC for a brushless motor. If they need 200 RPM at 2Nm of torque, we might suggest a lower 15:1 ratio, 10% overvoltage with proper heat monitoring, and upgraded graphite brushes.
Over the years, I’ve seen too many customers get frustrated when they try one trick that doesn’t work, so I always tell them to start with the simplest, cheapest fixes first. That means step one: check and calibrate your ESC (if it’s brushless) or power supply (if it’s brushed). Step two: inspect and replace worn brushes if needed. Step three: adjust the gear ratio. Step four: optimize lubrication. Step five: for experienced users, look into voltage adjustment or rewinding. That order avoids wasting money on expensive modifications when a 5-minute calibration would fix the problem.
At the end of the day, increasing the speed of a 48mm DC gear motor isn’t about pushing it as hard as you can—it’s about balancing speed with reliability and application needs. Our team has tested every one of these methods on our own 48mm motor models, so we know they work when implemented correctly. If you’re working on a project and need help figuring out the right way to boost your motor’s speed without damaging it, we’re here to help. We don’t just sell motors—we help you match the right motor and modifications to your exact application, so you get the speed you need without the headaches of premature motor failure.
If you’re ready to discuss your specific requirements, our team is available to walk through your project, answer questions about our 48mm DC gear motor line, and help you find the right solution. Let’s connect to tailor a plan that works for you.
Planetary Gearbox References
DC Motor Speed Control: Principles and Practices, Industrial Press Inc.
Gear Motor Design and Application Guidelines, Motion Control Association
Lubrication for Small Gear Motors, Tribology Transactions, Vol. 58, No. 3, 2015
I.CH Motion Co., Ltd.
I.CH Motion Co., Ltd. is one of the most professional 48mm dc gear motor manufacturers and suppliers in China, featured by quality products and good price. Please rest assured to buy cheap 48mm dc gear motor from our factory. Contact us for customized service.
Address: D2-1704, Vanke Duhui Tiandi, 28 Jiangnan Road，Dongshan Street, Jiangning District, Nanjing City, Jiangsu Province
E-mail: info@ichmo.com
WebSite: https://www.ichgearmotor.com/
