Our economy motor, (the E-150), is designed to give good performance at the lowest possible price.

Our mid-range motors, (F30-150 and F30-400), are designed for the highest performance and efficiency while still using the less expensive ferrite magnets.

These motors are used in diverse applications including robots, industrial motion control, factory automation, semiconductor manufacturing, motorized scooters, go karts, and electric bicycles.

We stock six different brushed motors or we can design custom brushed or brushless motors:

Horsepower, Torque, and RPM

The horsepower and torque of our high-performance motors are higher than other reversible, permanent magnet motors in this size range. Some gearmotors can't even achieve these high torque levels, even after multiplying the torque with a gearbox. (Please note that the above torque figures are the theoretical peak torques when stalled. Operating any high-performance motor while stalled will damage it).

Usually, the higher the voltage and RPM of a motor, the higher its efficiency will be. Some motors have high efficiency, but at a no-load speed of 20,000 RPM or more. Gearing such high RPM down to a usable speed takes several stages of gear reduction. This is heavy and expensive and the efficiency advantage usually disappears. The tricky part is making a moderate speed motor that is also highly efficient. The relatively low RPM of our motors makes any required speed reduction much easier. Using one or two stages of roller chain and sprockets is an easy and inexpensive way achieve speed reduction.

The A40 being tested on a dynamometer

Solid Construction - Easy Mounting

These motors are made from two sturdy aluminum castings and a seamless body. The long output shaft makes it easy to mount pulleys, sprockets, and gears in just the position you need them. A second 1/2" diameter shaft extends 3/4" from the rear of most models. This is very handy for mounting encoders, fans, tachometers, brakes, or other devices.

Some motors use an internal fan to reduce overheating. Our motors are efficient enough to operate without a fan. This has three advantages: (1) The motor housing is completely sealed so nothing can enter the motor and damage it; (2) The sealed motor tends to contain radio-frequency noise that would otherwise escape through the ventilation holes; (3) Increased efficiency because the energy that would normally be used to run the fan generates mechanical power instead.

A40-300                                           
  

The armature rides in two large high-quality ball bearings and it is dynamically balanced using epoxy rather than by the normal method of drilling the laminations. Drilling can cause eddy currents in the laminations, which increase motor heating.

Each of the four brushes has its own heavy-duty motor lead made from mil-spec 12-gauge flexible stranded wire, (10-gauge for the A40). Each copper strand is coated with pure silver to protect against oxidation and to get the lowest possible resistance in crimped connections. These leads are flexible but not "floppy", so they tend to stay where you put them. The four leads have high-temperature Teflon insulation rated for 200C, (392F).

Efficiency

Getting high efficiency from a low-Voltage motor is not easy. There are many factors that effect efficiency. We have optimized each of these factors to achieve the amazing efficiency of these motors.

As you can see from the above chart, the efficiency of the motors is very high over a broad range of power. Our motors are shipped with neutral timing so the performance is the same in both directions.

The armatures are wound with heavy gauge wire, and all the space in the armature is used. We left no power-robbing "empty air" in the slots; they are packed with copper! The smaller motors have skewed armature laminations to eliminate the heavy "cogging" that results from using the extremely powerful neodymium magnets. The A40 motor uses straight laminations, but the cogging is kept to a very low level by using a 42-bar commutator. The huge 1.75" diameter of the commutator combined with the four massive brushes and the 42 bars enabled us to get high power and high efficiency from this smooth-running motor, (the smaller motors have 21 bars). As far as we know, our high-performance motors have the highest efficiency of any 24-volt reversible permanent magnet DC brush motors in their size ranges.

Another benefit of the four-brush, 42 and 21-bar designs is the absence of excessive electrical noise. While all motors produce some electrical noise, cheaper motors with fewer commutator bars are more likely to send noisy voltage spikes back to your controller.

Radio-frequency noise is further reduced by the use of internal capacitors. The four-brush motors come with four capacitors built right in to the motors. Each of the four brushes has a capacitor wired to its nearest neighbor on each side. This makes the motors ideal for radio-controlled applications.

Using rare earth magnets is normally the only way to get high efficiency from a low-Voltage motor. While these magnets are very strong, they are also extremely expensive. We use neodymium rare earth magnets in the A28 motors To reduce the cost of our other motors, we use a high-energy ferrite magnet known as "T9". The T9 magnet material along with the other design features listed above have enabled us to achieve the same high efficiency of rare-earth in much less expensive motors.

Motor Control

     A28-400
The high current these motors are capable of drawing requires the use of high quality controllers. Please see our Motor Controller page. Optical encoders are available from many sources. US Digital offers a wide range of competitively priced products.

Choosing a motor

The A28s have incredible power to weight ratios and for weight-sensitive applications these would be the best choice. The A40 weighs more than the A28s, but in some cases this is advantageous. The higher motor mass will decrease the rate of motor heating for a given level of power. If you need high power for several minutes or moderate power for an extended time, the larger A40 is a better choice. Our F30 motors have an excellent balance between cost and performance. And the E-150 is a solid low-cost alternative.

Technical Specifications:

9mm and 1/2" Sprockets and Keys	E-150 Economy Motor
The 12mm bore of our metric sprocket fits the shaft of the E-150 and it comes with the required 3mm key. The 1/2" bore of our standard sprocket works with all other motors except the A40-300. It comes with a 1/8" key. Both have 9 teeth and work with #35 roller chain.

Warrantee
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.

Ordering
Shipments must be to a street address; we can not ship to a PO Box. Please allow 7-10 days for orders shipped by UPS ground, 3-4 days for orders shipped by 2nd day air, and up to 14 days for international orders.