JMC Motors – Servo and Closed-Loop Drives with Integrated Driver
JMC (Just Motion Control) builds compact drives in which motor, encoder and driver are merged into a single unit. This eliminates the separate driver cabinet, simplifies wiring and makes high-quality, closed-loop drive technology affordable even for the ambitious DIY builder. At Rocketronics you get the complete JMC range – integrated servo motors and closed-loop stepper motors – together with power supplies, connectors, cables and accessories, ready to ship from stock.
Servo or Closed-Loop Stepper Motor – the Essentials at a Glance
Both drive types work with encoder feedback and therefore never lose steps. The closed-loop stepper motor delivers its full torque at low speeds and is the cost-effective, smooth-running choice for most CNC routers and axes. The integrated servo motor spins faster (up to 5200 rpm), maintains its torque across a much wider speed range and suits dynamic, fast or continuously highly loaded applications. Rule of thumb: standard router → closed-loop; high speed, dynamics or continuous load → servo.The Two JMC Product Families
Closed-Loop Stepper Motors (iHSS / iHSSC)
Stepper motor with optical encoder (1000 lines) and integrated power stage. Detects position deviations instantly and corrects them – there are no step losses. High holding torque, quiet running, low price. Available from 0.48 Nm (NEMA17) to 12.2 Nm (NEMA34), optionally with holding brake. To the closed-loop overview »
Integrated Servo Motors (iHSV / iHSVC)
Brushless servo motor with encoder and integrated servo controller in a single housing. High speeds, wide torque band, very dynamic. Available from 52 W (NEMA17) to 660 W (NEMA34), optionally with holding brake for vertical axes. To the servo motor overview »Servo Motor vs. Closed-Loop Stepper Motor Compared
| Property | Closed-Loop Stepper Motor (iHSS) | Integrated Servo Motor (iHSV) |
|---|---|---|
| Torque at low speed | Very high | Medium–high |
| Behaviour at high speed | Torque drops off | Torque maintained for long |
| Maximum speed | typ. usable up to ~1000–1500 rpm | 3000 rpm nominal, up to 5200 rpm |
| Dynamics / acceleration | Good | Very high |
| Smoothness | Very smooth | Smooth |
| Step losses | No (encoder control) | No (encoder control) |
| Price | Lower | Higher |
| Typical use | CNC router, standard axes | Fast/dynamic axes, continuous load |
| Frame sizes | NEMA17 / 23 / 24 / 34 | NEMA17 / 23 / 24 / 34 |
| Brake optional | Yes | Yes |
Not sure which to choose? The selection guide leads you to the right motor based on your machine and requirements.