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DC servo motor

ElectroCraft RapidPower Xtreme (RPX) DC servo motor

Compact brushless DC motors in 16.25, 22, 32, 40 and 52 mm frames with 12, 24 or 48 V windings and peak torque from 35 mNm to 3.15 Nm (series maximum); LRPX planetary gearmotor versions reach 22.5 Nm.

Key specifications

Voltage (max)48 V
Peak torque (max)3.151 Nm
Frame sizes16.25, 22, 32, 40, 52
Supply12, 24 or 48 V windings
Gearmotor torqueLRPX up to 22.5 Nm peak

Summarised in our own words from ElectroCraft, Inc.'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1

Notes on this data

Continuous torque, speed and power not published on the overview page.

Specify Motion is not affiliated with ElectroCraft, Inc.. ElectroCraft and RapidPower Xtreme (RPX) are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.

Typical applications

Medical devicesPortable equipmentRoboticsPumps

Alternatives that meet or exceed these figures

Engineers often come to us with an ElectroCraft part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.

Meets or exceeds on the published figure compared

Leadshine low-voltage PMSM servo motors from a 25 mm 33 W unit up to a 130 mm 2 kW unit, wound for 24-60 V DC buses. Fully published data covers torque to 6.4 Nm rated / 16 Nm peak, 17-bit absolute or 2500 ppr incremental encoders and IP65. Designed for ELD2, 2ELD2 and ELD3 drives.

Published maximumRapidPower Xtreme (RPX)ELVM Series Low-Voltage DC Servo Motors
Rated torque—6.4 Nm
Peak torque3.15 Nm16 Nm meets or exceeds
Speed—6,000 rpm
Power—2,000 W
View ELVM Series Low-Voltage DC Servo Motors →

Low-voltage brushless DC servo motors for 48 or 96 VDC systems, with a 12-slot/10-pole design, matched to the Kinco FD1X5 drive and aimed at robotics, CNC and automated lines.

View SMK Series Low-Voltage DC Servo Motors →

Low-voltage (24-48 VDC) brushless servo motors with a 12-slot/10-pole low-cogging design, IP65 and a choice of optical or magnetic, incremental or absolute encoders. Matched to Kinco FD1 and OD drives for battery-powered and mobile machines.

View SMC Series Low-Voltage DC Servo Motors →

Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.

What a DC servo motor is

A DC servo motor, in current usage, is usually a low-voltage brushless permanent-magnet motor designed to run from a DC bus, typically 24 to 96 V, under closed-loop servo control. Electronically it works like an AC servo, with a three-phase stator commutated by the drive and encoder or Hall feedback on the shaft. The lower voltage means higher current for the same power, but suits battery-powered and safety-extra-low-voltage machines. Small precision brushless servomotors also fall into this group.

When engineers choose a DC servo motor

Choose a low-voltage DC servo for mobile robots, AGVs, battery equipment, medical devices and compact machines where mains voltage is impractical or unsafe. It allows simple power distribution and safe access. The trade-offs are current and power range: high current means thicker cables and higher losses, so power is typically limited to a few kilowatts. For mains-powered machines above that, an AC servo is usually simpler.

How to specify the ElectroCraft RapidPower Xtreme (RPX)

Send these with your enquiry and an engineer can confirm the right RapidPower Xtreme (RPX) variant or an equivalent:

  • Bus voltage (V DC) and battery range
  • Continuous and peak torque (Nm)
  • Rated and maximum speed (rpm)
  • Continuous and peak current (A)
  • Feedback type and resolution
  • Brake, IP code and frame size (mm)
  • Drive and network interface

Common mistakes to avoid

  • Sizing at nominal battery voltage without checking the low-charge end
  • Undersizing cables for the higher current
  • Ignoring regenerative energy into a battery or supply
  • Mixing motor and drive feedback types that are not compatible

ElectroCraft RapidPower Xtreme (RPX): frequently asked questions

What is the ElectroCraft RapidPower Xtreme (RPX)?

Compact brushless DC motors in 16.25, 22, 32, 40 and 52 mm frames with 12, 24 or 48 V windings and peak torque from 35 mNm to 3.15 Nm (series maximum); LRPX planetary gearmotor versions reach 22.5 Nm. Published series figures include voltage 48 V, peak torque 3.151 Nm. It is made by ElectroCraft, Inc.; Specify Motion can help source it or propose an equivalent.

Who makes the ElectroCraft RapidPower Xtreme (RPX)?

The ElectroCraft RapidPower Xtreme (RPX) is made by ElectroCraft (ElectroCraft, Inc.) and is listed here for engineers comparing options. Specify Motion is not affiliated with ElectroCraft, Inc.; brand names are used only to identify the product.

What is the voltage of the ElectroCraft RapidPower Xtreme (RPX)?

The published series maximum voltage is 48 V. Individual models and sizes in the RapidPower Xtreme (RPX) range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.

Is there an alternative to the ElectroCraft RapidPower Xtreme (RPX)?

Yes. On published figures, Leadshine ELVM Series Low-Voltage DC Servo Motors and Kinco SMK Series Low-Voltage DC Servo Motors are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.

What is the difference between an AC servo and a DC servo motor?

Both are typically brushless permanent-magnet motors under closed-loop control. The main difference is the supply: AC servos are wound for drives fed from mains voltage, while DC servos are wound for low-voltage DC buses. DC servos suit battery and low-voltage machines; AC servos suit higher-power mains machines.

How does battery voltage affect a DC servo motor?

Motor speed is roughly proportional to available voltage, so as a battery discharges the top speed falls. Size the motor at the lowest working battery voltage. Also allow for regenerative energy during braking, which raises bus voltage and must be absorbed by the battery or a braking circuit.

Further reading: How to select a servo motor · How to select a dc motor · Servo and stepper motors

Other dc servo motor series

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