This documentation is no longer maintained. For documentation of the current version of emc2, please see http://www.linuxcnc.org/docview/html

# Quick Start Guide for Stepper Configurations

Set machine units: You need to decide whether you want the machine to use inches or millimeters by default. This is done by choosing either the stepper/stepper_inch config or the stepper/stepper_mm config. The first time you run EMC2, a dialog will prompt you to copy the configuration to your home directory. You should select ``yes''.

Before going on, you should open the ini file in a text editor. The file will be in your home directory under emc2/configs/stepper/stepper_inch.ini (or stepper_mm.ini if you chose that config).

Determine the size of a step: EMC2 needs to know how far your machine will move for each step pulse it sends to the motors. The equation to calculate this is

steps * usteps * pitch * ratio, where

steps is the number of steps per revolution for your motor (usually 200)

usteps is the number of microsteps your drive is set to. This is 2 for half stepping, 4 for quarter stepping, etc.

pitch is the screw pitch: How many turns does it take to move the table one unit?

ratio is the drive ratio between the motor and the screw. If using a belt or gear drive, use the final drive ratio.

So, for a standard stepper (200 steps/rev), using Gecko drives (10x microstepping), a 10 pitch screw, and 2:1 belt drive, the formula is:

200 * 10 * 10 * 2 = 40000 steps/inch

This needs to be determined independently for each axis.

Let's set the X axis resolution to 40000 steps/inch. Find the [AXIS_0] section of the ini file. This contains all of the X-axis specific information. Change INPUT_SCALE (yes, input - EMC2 still keeps track of where the motor should be) to 40000. The other axes would be done the same way (Y = AXIS_1, Z = AXIS_2 ...)

Set up the parallel port connections: You need to tell EMC2 where you stepper drives are connected to the computer. There are two sample confi

Set up stepgen: Stepgen is the module EMC2 uses to convert the position outputs from the trajectory planner to steps for the motor.

2007-01-26