Three-Inch High Performance Electric Motors
High Performance A28 Motors
AmpFlow high-performance A28 electric motors use neodymium rare-earth magnets to deliver industry-leading torque and efficiency in a 3-inch brushed DC motor. Ideal for industrial motion control, precision positioning systems, AGVs, and demanding robotics applications.
Mid-Range F30 Motors
The F30 mid-range electric motors deliver high performance and efficiency using ferrite magnets, making them a cost-effective alternative to the A28 for factory automation, assembly line equipment, and motion control applications.
Fan-Cooled A28 Motors
Fan-cooled A28 electric motors are designed for applications requiring longer duty cycles and higher continuous power output. Low-profile leads enable more compact installations. Available in 24V and 48V for industrial machinery and surveillance robots.
Economy E30 Motors
The E30 economy electric motors deliver reliable brushed DC motor performance at the lowest possible price, making them popular for personal transport systems, educational projects, robot sports, animatronics, and cost-sensitive industrial applications.
All motors on this page are available with the optional AmpFlow speed reducer or planetary speed reducer.
We stock all the motors on this page. Custom motors are also available with a minimum order of 24 units.
| High Performance Economy Motors | ||||||
| Voltage Range | 6 Volts to 18 Volts | 12 Volts to 36 Volts | 24 Volts to 72 Volts | |||
| Model | E30-400-12 | E30-150-12 | E30-400-24 | E30-150-24 | E30-400-48 | E30-150-48 |
| Diameter (inches) | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 |
| Length (inches) | 5.8 | 4.0 | 5.8 | 4.0 | 5.8 | 4.0 |
| Peak HP | 1.6 | 0.6 | 2.1 | 1.0 | 2.7 | 1.1 |
| Stall Torque (oz-in) | 970 | 420 | 1500 | 710 | 1860 | 750 |
| Efficiency | 78% | 72% | 79% | 76% | 82% | 77% |
| Nominal Voltage | 12V1 | 12V1 | 24V1 | 24V1 | 48V1 | 48V1 |
| RPM at Nominal Voltage | 6500 | 5400 | 5700 | 5600 | 5800 | 5600 |
| Shaft Diameter (inches) | 1/2 | 1/2 | 1/2 | 1/2 | 1/2 | 1/2 |
| Shaft Length (inches) | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 |
| Keyway (inches) | 1/8 | 1/8 | 1/8 | 1/8 | 1/8 | 1/8 |
| Capacitors | No | No | No | No | No | No |
| Magnet Type | Ferrite | Ferrite | Ferrite | Ferrite | Ferrite | Ferrite |
| No Load Amps | 5.5 | 3.5 | 3.2 | 2.1 | 1.4 | 1.0 |
| Resistance (Ohms) | 0.030 | 0.081 | 0.089 | 0.190 | 0.284 | 0.708 |
| Kt (oz-in/Amp) | 2.46 | 2.93 | 5.63 | 5.70 | 11.1 | 11.4 |
| Kv (RPM/Volt) | 549 | 461 | 240 | 237 | 122 | 118 |
| Weight (pounds) | 5.9 | 3.6 | 5.9 | 3.6 | 5.9 | 3.6 |
| Price | $119 | $89 | $119 | $89 | $119 | $89 |
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| High Performance | Mid-Range | |||
| Model | A28-400 | A28-150 | F30-400 | F30-150 |
| Diameter (inches) | 3.0 | 3.0 | 3.1 | 3.1 |
| Length (inches) | 6.7 | 4.0 | 6.7 | 4.0 |
| Peak HP | 4.3 | 3.0 | 2.5 | 2.3 |
| Stall Torque (oz-in) | 3560 | 1950 | 2240 | 1370 |
| Efficiency | 83% | 80% | 84% | 82% |
| Nominal Voltage | 24V1 | 24V1 | 24V1 | 24V1 |
| RPM @ 24V | 4900 | 6100 | 4500 | 6900 |
| Shaft Diameter (inches) | 1/2 | 1/2 | 1/2 | 1/2 |
| Shaft Length (inches) | 2.0 | 2.0 | 2.0 | 2.0 |
| Keyway (inches) | 1/8 | 1/8 | 1/8 | 1/8 |
| Capacitors | Yes | Yes | Yes | Yes |
| Magnet Type | Neodymium | Neodymium | Ferrite | Ferrite |
| No Load Amps | 4.4 | 4.4 | 2.1 | 2.5 |
| Resistance (Ohms) | 0.044 | 0.064 | 0.076 | 0.081 |
| Kt (oz-in/Amp) | 6.58 | 5.26 | 7.17 | 4.66 |
| Kv (RPM/Volt) | 205 | 257 | 189 | 287 |
| Weight (pounds) | 6.9 | 3.8 | 8.3 | 4.7 |
| Price | $569 | $409 | $339 | $299 |
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Fan-cooled Motors
| Fan Cooled 24V | Fan Cooled 48V | |||
| Model | A28-400-F24 | A28-150-F24 | A28-400-F48 | A28-150-F48 |
| Diameter (inches) | 3.0 | 3.0 | 3.0 | 3.0 |
| Length (inches) | 7.8 | 5.1 | 7.8 | 5.1 |
| Peak HP | 4.3 | 3.0 | 11.52 | 4.6 |
| Stall Torque (oz-in) | 3560 | 1950 | 72602 | 2500 |
| Efficiency | 83% | 80% | 85% | 82% |
| Nominal Voltage | 24V1 | 24V1 | 48V1 | 48V1 |
| RPM at Nominal Voltage | 4900 | 6100 | 6400 | 7400 |
| Shaft Diameter (inches) | 1/2 | 1/2 | 1/2 | 1/2 |
| Shaft Length (inches) | 2.0 | 2.0 | 2.0 | 2.0 |
| Keyway (inches) | 1/8 | 1/8 | 1/8 | 1/8 |
| Capacitors | Yes | Yes | Yes | Yes |
| Magnet Type | Neodymium | Neodymium | Neodymium | Neodymium |
| No Load Amps | 4.4 | 4.4 | 4.4 | 2.5 |
| Resistance (Ohms) | 0.044 | 0.064 | 0.066 | .165 |
| Kt (oz-in/Amp) | 6.58 | 5.26 | 10.05 | 8.70 |
| Kv (RPM/Volt) | 205 | 257 | 135 | 156 |
| Weight (pounds) | 7.2 | 4.0 | 7.3 | 4.0 |
| Price | $619 | $459 | $619 | $459 |
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The fan motors have ventilation holes in the front and rear aluminum plates to allow for flow-through cooling. The holes in the front plate are positioned so they are not blocked when mounting the motor to a flat surface. These motors also feature low-profile motor leads for better fit into smaller spaces.
1 The above specifications are for the motor's nominal voltage. The motors can also be used at lower or higher voltages. The RPM is proportional to the voltage, so running at half the nominal voltage will result in half the speed, and twice the voltage will double the speed. The maximum achievable torque is also proportional to the voltage. Shorter duty cycles are recommended for higher voltages to allow the motors time to cool. Please note that the above torque figures are the theoretical peak torques when stalled. Operating any high-performance motor while stalled will damage it.
2 Theoretical peak power is 11.5 HP. Power at the recommended short-term current limit of 200A is 9.1 HP. The current required to reach 7260 oz-in is far outside the safe operating limits of this motor. This figure is theoretical and should be used for comparative purposes only.
Efficiency
Getting high efficiency from a low-voltage motor is not easy. There are many factors that affect efficiency. We have optimized each of these factors to achieve very high efficiency in these motors.
| High Performance Economy Motors | ||||||
| Voltage Range | 6 Volts to 18 Volts | 12 Volts to 36 Volts | 24 Volts to 72 Volts | |||
| Model | E30-400-12 | E30-150-12 | E30-400-24 | E30-150-24 | E30-400-48 | E30-150-48 |
| Peak Efficiency (PE) | 78% | 72% | 79% | 76% | 82% | 77% |
| RPM at PE | 5800 | 4700 | 5100 | 5000 | 5300 | 5000 |
| Torque at PE (oz-in) | 105 | 57 | 145 | 85 | 150 | 80 |
| Horsepower at PE | 0.60 HP | 0.26 HP | 0.75 HP | 0.40 HP | 0.80 HP | 0.40 HP |
| Current at PE | 48 Amps | 23 Amps | 29 Amps | 17 Amps | 15 Amps | 8 Amps |
| High Performance | Mid-Range | |||
| Model | A28-400 | A28-150 | F30-400 | F30-150 |
| Peak Efficiency (PE) | 83% | 80% | 84% | 82% |
| RPM at PE | 4500 | 5500 | 4200 | 6300 |
| Torque at PE (oz-in) | 300 | 190 | 170 | 120 |
| Horsepower at PE | 1.3 HP | 1.0 HP | 0.71 HP | 0.74 HP |
| Current at PE | 50 Amps | 40 Amps | 26 Amps | 28 Amps |
| Fan Cooled 24V | Fan Cooled 48V | |||
| Model | A28-400-F24 | A28-150-F24 | A28-400-F48 | A28-150-F48 |
| Peak Efficiency (PE) | 83% | 80% | 85% | 82% |
| RPM at PE | 4500 | 5500 | 6000 | 6750 |
| Torque at PE (oz-in) | 300 | 190 | 510 | 220 |
| Horsepower at PE | 1.3 HP | 1.0 HP | 3.0 HP | 1.5 HP |
| Current at PE | 50 Amps | 40 Amps | 55 Amps | 28 Amps |
As you can see from the above charts, the efficiency of the motors is very high over a broad range of power.
Replacement parts are available here.
Optical Encoder
Hover to see mounted optical encoder
All our three-inch motors (other than the fan motors) can be supplied with an optical encoder. The encoder mounts on the back of the motor, and it comes with a 20-inch cable. It has 512 PPR and an index. Here is the wiring chart:
| Black | Ground |
| Yellow | Index |
| White | Channel B |
| Red | +5VDC |
| Green | Channel A |
We can mount the encoder, or it can be ordered separately.
Sprockets and Keys
The 1/2-inch bore of our standard sprocket fits all the motors on this page. The sprocket has 9 teeth and it works with #35 roller chain. It comes with a 1/8-inch key.
Applications
AmpFlow 3-inch electric motors are used across a wide range of industries and applications.
- Automated Guided Vehicles (AGV): Motors for warehouse robotics
- Factory Automation Systems: DC motors for plant machinery
- Industrial Motion Control: Motors for closed-loop industrial automation
- Precision Positioning Systems: For multi-axis stages and CNC machinery
- Assembly Line Equipment: Motors for pick-and-place systems and indexing tables
- Bomb and Mine Removal Robots: Actuator motors for EOD robotic arms
- Personal Transport Systems: Drive motors for electric scooters
- Solar Tracking Arrays: 24V and 48V positioning motors
- Semiconductor Manufacturing: Cleanroom-compatible motors (special order)
- Laboratory Automation: Motors for clinical testing equipment
- Surveillance Robots: Motors for mobile perimeter security patrols
- Robot Sports: DC motors for combat robots and robotic soccer
- Hazardous Material Handling Robots: Motors built for extreme environments
- Animatronics: Motors for movie special effects and theme park figures
- Electric Lawnmowers: DC motors for landscaping equipment
Our pancake motors or standard motors are typically used in motorized bicycles and scooters.
Here are our recommendations regarding the selection of a proper reduction ratio.
Warranty
The motors are warranted to be free from manufacturing defects, and fully operational when you receive them. AmpFlow gives no other warranty, either expressed or implied. Warranties are not transferable. In no event shall AmpFlow's liability exceed the buyer's purchase price, nor shall AmpFlow be liable for any indirect or consequential damages.
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Contact us for custom motors and volume pricing: