Rotalink Ltd


Rotalink offers an extensive and growing catalogue of power transmission and control products including AC synchronous and shaded pole motors, brushed and brushless DC motors, permanent magnet and hybrid stepping motors, gearboxes up to 15Nm and auxiliary products ranging from encoders to lead screws.

Our own cost driven manufacturing facility has a varied process capability including injection moulding, coil winding and CNC turning. It utilizes the latest CAD technology and is supported by a number of worldwide partnerships. Our multi-disciplined sales and engineering team will work with you to produce the most effective solution for your application.

Permanent Magnet Brushed DC Motors

The simple permanent magnet brushed dc motor is an impressive component. Continuous improvement has delivered powerful and flexible performance at the very lowest cost.

Advantages of a brushed DC motor include low initial cost, high reliability, and simple control of motor speed.

Rare Earth DC Motors

Rare earth magnet motors can be a cost effective option when high speed, high efficiency, long life or small size are important. This low cogging motor range offers greater power compared with other brushed motors of the same volume. This is achieved using very thin Neodymium magnets, high density windings and a 6 slot core.

Brushless DC Motors

Brushless dc motors are commonly used where precise speed control, low electrical noise or long life is necessary. They are typically 75-80% efficient and often use a permanent magnet internal rotor, three phases of driving coils and hall effect sensors.

Brushless motors do not spark making them ideal for EMC sensitive applications.


Our innovative gearbox design expertise together with today’s materials have been combined to maximise the full output power generated by this widest range of motors in the most price sensitive way. Each gearbox type is offered with many ratios, torque of 10mNm to 20Nm is achievable through the range with speeds peaking at 500 rpm.

Low noise and extended life are characteristics that are high on our agenda.

Incremental Encoder

The dual channel incremental encoder is an optical device giving 48 line quadrature output per rev of the motor and 192 positions per rev with signal processing. Operating from a standard 5 volt supply to directly drive TTL and CMOS logic. Available in two forms, mounted on a motor with rear shaft or mounted between the motor and the gearbox (allowing the customer to select a standard motor).
The single channel incremental encoder is a magnetic device giving 24 pulses per motor rev. operating from a supply of 3.8 to 30.0 volts. Ideal for use when interfacing with TTL and CMOS devices, this product offers a very cost effective answer to the customer’s feedback requirement when used in conjunction with brushed dc motors and gearboxes.

Absolute Encoder

Our absolute output shaft encoder provides accurate positional information unaffected by power loss and self correcting in the face of electrical interference. They operate via contactless magnetic technology providing either a linear analogue output (0-5V) or reliable 10bit positional data sent via a SSI (synchronous serial interface).

The single turn absolute encoder operates through the full 360° of rotation and accurately monitors its position indefinitely without power.

The multi turn operates through 32000 revolutions whilst still providing the maximum resolution of 10bits per 360° and is fitted with an integral rechargeable battery to provide full position monitoring for 20 hours when main power is removed.

DC Programmable Controller

The drive board was designed with cost at the forefront of the specification and manufactured in volumes that deliver this promise. Use Red Drive throughout the product development process. At the final stage you have the option to take the chip from Red Drive and incorporate it on your own board.

Red Drive is a compact yet powerful motor driver and controller. It is designed to be used with our encoders and wide range of dc motors and gearboxes. Our unique flowchart graphical software allows the user to easily program both simple and complex sequences of motion.

The Red Drive interacts with both analogue and digital inputs such as potentiometers, simple switches and many other sensors. Digital outputs are available to control LED’s, buzzers and other user defined outputs.

The software provides the user with an easy to use interface for defining all aspects of the controller. The simple drag and drop uses real world values such as rpm and seconds.


Speed Controller

An open loop Pulse Width Modulated speed and direction controller for use with brushed dc motors up to 1.5A.

Using the on board potentiometer it is easy to adjust direction and speed; with the potentiometer set full CW the motor turns clockwise at full speed, simply rotating the potentiometer to full AC will rotate the motor anticlockwise at full speed. Positioning the potentiometer at 50% will stop the motor.

Operating from a 7-24Vdc input voltage this controller uses PWM adjustment running at 20Khz to provide high quality speed control. The motor will see an average voltage proportional to the length of the pulses it is receiving – speed is increased by lengthening the pulse.

The Speed Controller has a small footprint measuring just 63x46mm.

Current Limiting Board

Use of the Current Limiting Board (electronic clutch) allows the maximum current available to a DC motor to be limited; this in turn limits the torque available from the motor and is particularly useful to protect gearboxes where an unlimited motor could apply a torque great enough to cause damage to the application or gearbox. We configure each pcb to limit the current as required by your application.

The Current Limiting Board can provide up to 2000mA at 12Vdc and 800mA at 24Vdc. Current limitation is available in both single and bi-directional mode. The board has an inbuilt thermal protection device rated at 6 Watts, these graphs show the effect of operating time on the current limiting board.

AC Synchronous Motors

Our range of ac synchronous single and reverse direction motors offer geared torque up to 4Nm. The direction of rotation is electrically switched or controlled by long-life mechanical anti-return devise. UL approved options are available. These long life motors are suitable for use in medical equipment, valves and pumps.

Permanent Magnet (PM) Stepping Motors

Often referred to as a “tin can” the permanent magnet step motor is a low cost, low resolution motor. Our range of 25-55mm diameter uni and bi polar motors offer geared torque up to 10Nm with typical step angles of 7.5° to 15° (48–24 steps/revolution).  

Hybrid (HB) Stepping Motors

The hybrid stepper motor provides higher step resolution, torque and speed performance than a PM stepper motor. We have an extensive range of HB motors up to Nema size 23 in uni and bi polar windings with step angles of 3.6° to 0.9° (100 – 400 steps per revolution). Our stand alone SM02 unipolar drive offers low cost control up to 1A per phase.

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