Welcome to 4QD – Electric Motor Control

We manufacture a range of  DC motor speed controllers and accessories for battery powered electric motors that are tough, reliable, and easy to use.

Our passion is getting stuff working – industrial machines as well as hobbyist.

• Industrial – we help engineers develop motor controller solutions for a wide range of industrial machines in many sectors worldwide. Have a look here – see if we can help you.
• Hobbyist – our controllers are used in model locomotives, electric vehicles, boats, robots and many other DIY projects. Have a look here to see some great examples.

We love helping mechanics get the electrics working, and can provide electric motor speed control solutions for almost anything with a battery and a DC electric motor, to see the sort of thing we’ve done have a look here,  or just browse around the site, all of the pictures throughout this site are using our controllers.

• Our motor controller range covers 30 to 300 amps, 12 to 84 volts, and can be used in a wide variety of applications that use permanent magnet electric motors.
• Our new Pro-160 is the only controller on the market with a remotely mountable display showing voltage, current, and temperature.
• All our products are easy to wire up and adjust.
• We enjoy providing any additional technical support you need to get your project up and running.
• We have a range of additional heatsinks available, if you need a high power, water cooled PWM controller ours are some of the best value on the market.
• Our controllers are reliable, many are still going strong after 20 years.
• We will ship to any country.
• We have an extensive knowledge base with lots of technical support, manuals, wiring diagrams and background information on a wide range of motor control topics e.g. what is PWM? and how is H-bridge switching done? If you prefer videos, then we’ve got a selection on installation, troubleshooting, and general interest here.
• We love talking to customers about their applications and would like to hear from you if you have a special project or ideas for new products.
• We can help with designing wiring looms for projects.
• We can develop bespoke control products and software [depending on volume].

For help choosing a controller click here

Come and have a look… our controllers are here, and our accessories are here.

Or just pick up the phone, we’re on 01487 450520 and are always happy to chat about your project.