Use clockwise arcs or counterclockwise arcs to draw a circle. The direction is viewed from the positive direction of the Z-axis, where the circular motion occurs.

This method uses two different ways to control the arc path depending on the input parameters:

  1. Center mode – i.e., the center of the circle is given with the end point position to calculate the path of the arc.
  2. Radius mode – i.e., the radius and the end position are given to calculate the path of the arc.

Note that either arc motion method may result in the target not being on the circle due to parameter setting error, which will result in unintended motion of the machine.

For more information about the various motion methods, please refer to the Motion Method Explanation page.


machine.arcXY(r, dstX, dstY);
machine.arcXY(r, dstX, dstY, revDir);
machine.arcXY(r, dstX, dstY, revDir, feedrate);
machine.arcXY(cX, cY, dstX, dstY);
machine.arcXY(cX, cY, dstX, dstY, revDir);
machine.arcXY(cX, cY, dstX, dstY, revDir, feedrate);


  • machine: for Machine object.
  • r: The radius of the circle in radius mode.
  • cX: The center X coordinate of the circle in center mode.
  • cY: the center Y coordinate of the circle in center mode.
  • dstX: The target X coordinate.
  • dstY: Target Y coordinate.
  • revDir: reversing direction, use true when counterclockwise, use false when clockwise, default is clockwise.
  • feedrate: Feedrate, the last recorded feedrate will be used when no parameter is passed.



  • true: The machine exists and was created successfully.
  • false: The machine does not exist or failed to be created.


Set the basic parameters of the machine and use the machine to do the arc motion in XY plane in two modes respectively.

#include "Motion86.h"
// Generate machine objects, up to machine 0~2 three machines, each machine has three axes. 
Machine machine(0);
// Stepper motor enable pin.
int EnablePin = 4;
void setup() {
  while (!Serial);
  pinMode(EnablePin, OUTPUT);
  // If necessary, the motion direction of the motion axis can be reversed.
  // In this example, the direction of x-axis and y-axis should be reversed.
  // PPU (pulse per unit) is a virtual length unit, depending on different requirements.
  // In this example, the unit length of x-axis is set to 80 pulses, which corresponds to 1 mm in real application.
  machine.config_PPU(AXIS_X, 80.0);
  machine.config_PPU(AXIS_Y, 80.0);
  machine.config_PPU(AXIS_Z, 1600.0);
  // The machine must be started before control.
  // Start the stepper motor.
  digitalWrite(EnablePin, LOW);
void loop() {
  // Move clockwise with radius 10 to (10, 10, 0).
  machine.arcXY(10, 10, 10, true);
  // Move counterclockwise to (0, 0, 0) with radius 10.
  machine.arcXY(10, 0, 0, false);
  // Move clockwise to (10, 10, 0) with the center of the circle (0, 0, 10).
  machine.arcXY(0, 10, 10, 10, true);
  // Move counterclockwise to (0, 0, 0) with the center of the circle (0, 0, 10).
  machine.arcXY(0, 10, 0, 0, 0, false);
  // Wait until the planned motion is completed.
  while (machine.isMoving());

See also

Libraries Reference Home

The text of the 86Duino reference is a modification of the Arduino reference and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.

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