Getting Started: What is a SmoothStepper?

SmoothSteppers are used to control Mills, Lathes, Router and Laser tables, Plasma and Oxy-Acetylene tables, Waterjet and Ultrasonic Cutters, Drag Knives, Pipe Benders and many other devices that can be controlled by GCode.

The SmoothStepper is a high-performance external motion controller that interfaces between your PC and your CNC equipment. It is a 6-axis motion control device that accepts commands from a trajectory planner (i.e. Mach3 or Mach4) and produces a very high quality pulse train to drive stepper and servo motor drivers.

We produce two SmoothStepper models, both of which have connectors that conforms to the Parallel Port standard.  The Ethernet SmoothStepper (ESS) connects to your PC via Ethernet, has 3 parallel ports.  The USB SmoothStepper (USS) connects to your PC via USB, has 2 parallel ports and a third dedicated input port.  The SmoothStepper's parallel ports allow it to integrate seamlessly with most external devices (CNC equipment and Break Out Boards) that require a Parallel Port interface, with only a ribbon cable to connect them together. 

Here is a basic connection diagram showing how the the Ethernet SmoothStepper connects to your PC and Break Out Boards or Motor Drivers:

ESS

Here is a basic connection diagram showing how the the USB SmoothStepper connects to your PC and Break Out Boards or Motor Drivers:

USS

 

Here are specific product details for the Ethernet SmoothStepper (ESS) and the USB SmoothStepper (USS).

 

There are several styles of Parallel Ribbon cables available, depending on your needs.   Also some Break Out Boards connect directly to the SmoothStepper.  Please note that the SmoothStepper uses a 26 pin header and not a parallel port DB-25 connector.

 

Keep in mind that the SmoothStepper and compatible BOBs will use this Parallel Port pinout numbering style (click here for more details):

Parallel Port Pinout

 

Here is a schematic showing the input and output capabilities of the Ethernet SmoothStepper:

ESS Port IO

 

You can choose any input pin for any input source you want (X home switch, Z limit switch, Probing, etc...). 

You can choose any output pin for any output signal you want (X Step, Y Dir, Flood, Mist, Spindle, Alarm, etc...).

A single ESS has 3 parallel ports (replacements) on it, giving you 51 total I/O pins to work with. Those 51 pins consist of 20 dedicated output pins, 15 dedicated input pins, a group of 8 bidirectional I/O pins that may be set as a group as either inputs or outputs and then a second group of 8 bidirectional I/O pins that may be set as a group as either inputs or outputs.  To change the bidirectional I/O pin functionality, click here for Mach4 or over here for Mach3.

 

ESS Board Rev 2

ESS

 

There have been quite a few people that use those 51 I/O pins to control two separate CNC machines (like a mill and a lathe) - just not simultaneously - one machine or the other at any specific time.

A single ESS can only talk to a single instance of Mach. You can only have a single instance of Mach3 running on a PC at a time. You can only have a single instance of Mach4running on a PC at a time. You might be able to run both Mach3 and Mach4 at the same time as long as they are talking to different SmoothSteppers.

 

 

Here is a schematic showing the input and output capabilities of the USB SmoothStepper:

USS Port IO

 

USS v1.2 Board Info

USS

You can choose any input pin for any input source you want (X home switch, Z limit switch, Probing, etc...). 

You can choose any output pin for any output signal you want (X Step, Y Dir, Flood, Mist, Spindle, Alarm, etc...). 

You may choose to assign the bidirectional Pins 2 through 9 on Port 2 to be all inputs or all outputs. You may choose to assign the bidirectional Pins 2 through 9 on Port 3 to be all inputs or all outputs.  Here is how.

 

If you are just getting started with Mach, seriously consider using Mach4 and NOT Mach3.  Mach3 is essentially end of life, and not supported with any new development.  Mach4 has new features under development and has much more in terms of capabilities and flexibility - especially with lua scripts.  However, the number one reason in our book is diagnostics, in Mach3 it is hard to determine what went wrong when something doesn't work. In Mach4 the diagnostics log and the screen set messages make it much easier to understand what is going wrong.

 

You will need a PC running anything from Windows XP to Windows 10, and on the PC you would install Mach3 or Mach4.   Mach interprets a G-Code file that you supply to it, and converts each G-Code movement into low-level commands.  These low-level commands are sent from the Mach SmoothStepper Plugin to the SmoothStepper hardware.  Mach calculates the incremental movements for all 6 axes, based on the number of steps per unit (mm or inches) of each axis, the current position, the current velocity, and the maximum velocity and acceleration constraints for each axis.  The SmoothStepper then sends Step & Direction signals to your motor drivers, which provide the high current and/or voltage needed to move your motors.  SmoothSteppers control tens of thousands of Lasers, Lathes, Mills, Routers, Jets, Plasma, Pipe Benders and other custom systems.

 

Since the SmoothStepper outputs 5V signals (with currents limited to 24 or 32 mA), you will need a motor driver between the SmoothStepper and the motor itself.  For your axes (X, Y, Z, A, B and C), the SmoothSteppers can control stepper motor drivers and digital servo motor drivers.   We do not support analog servo motor drivers or PWM servo motor drivers. 

 

The SmoothStepper is compatible with nearly all step & direction motor drivers.  The SmoothStepper also has quadrature and CW/CCW modes for high-end motor drivers, if that is what you are using.  Here are the specific product details for the SmoothSteppers.

 

Because the SmoothStepper is a dedicated hardware device, it is capable of producing pulses at very high frequencies and with extremely low jitter compared to the Parallel Port driver and microcontroller based solutions. In addition, the SmoothStepper is able to run on any flavor of Windows (XP and newer), both 32-bit and 64-bit. Mach will run under 32-bit or 64-bit, but Mach requires an external motion controller, such as the SmoothStepper, for all 64-bit editions of Windows.

 

 

Click here to continue with Getting Started: What Hardware Will I Need?

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