# NEMA 17 stepper skips steps: current, speed and acceleration

> Fix a stepper that loses position: raise the driver current within the motor rating, slow down, add acceleration and check the supply voltage.

Canonical: https://roboticsengineering.in/fix/nema17-stepper-loses-steps-skips-current-speed/ | Published: 2026-11-03 | Updated: 2026-11-03

**Lost steps mean the motor could not follow the commanded speed.** Slow down, ramp up smoothly and check the driver current.

## What the message means

A stepper has no feedback. If the load, speed or acceleration is too high for its torque, it skips steps and the machine does not notice.

## Fix it in this order

1. Set the driver current to the motor rating, not far below it.
2. Lower the top speed and add acceleration and deceleration ramps.
3. Use a higher supply voltage within the driver rating, since torque at speed depends on it.
4. Check the mechanics for binding, loose couplings and over-tight belts.
5. Keep the driver cool. Many drivers cut the current when hot.
6. Check for loose connectors on the motor wires.

## Why it happens

A stepper loses steps when the torque it must deliver is more than it has. The usual causes are a driver current that is set too low, a speed or acceleration that is too high, a low supply voltage, and a load that is too heavy or binding.

Set the driver current limit for the motor, add an acceleration ramp, for example with the AccelStepper library, lower the speed, raise the supply voltage within the driver rating, and check the mechanics.

## If you see this, do this

| You see | Do this |
| --- | --- |
| Skips at high speed | Lower speed, add ramps, raise voltage. |
| Skips at any speed | Current or mechanical binding. |

## Related

[stepper vibrates but does not turn](https://roboticsengineering.in/fix/stepper-motor-vibrates-but-does-not-turn/), [A4988 or DRV8825 not moving](https://roboticsengineering.in/fix/stepper-driver-a4988-drv8825-not-moving/).

Last reviewed: November 2026. These are the usual causes and the order that finds them fastest. Test on your own board; clones and cables differ.