Automation Artisan's

Electronic Lead Screw (ELS)

The simple way to automate your machinery

The ELS is a single board computer with 35 keys, a rotary encoder knob and 2x20 LCD display designed as an Open Source GPL project to control the Lead Screw and optionally the Cross Slide of a metal lathe. With the ELS, a machinist using a metal lathe can automatically thread metric or imperial and taper material more easily than with the lathe gear box. 

Simpler than a CNC application running on a PC, the ELS is tailored to compliment manual lathe operation with a command set that more closely matches how the lathe is used by an machinist.  In fact with the Electronic Half Nut control and a single motor on the carriage lead screw, the ELS behaves just like a standard lathe except you choose the pitch to thread or turn via the keyboard rather than hunting for the right gear combination.

A DB-25 connector on the back edge has the same pin allocation as a standard PC parallel port and along the side of the board are the connections for a 3 amp, 55 volt stepper motor.  The motor is controlled by the on board PIC micro-controller to have 8 micro-steps per step for a total of 1600 steps per revolution with a standard 1.8 degree bipolar motor.

Connections to the DB-25 include spindle encoder input along with a Limit Switch and Estop input.  Outputs include OC transistor drivers for external Online and Error LEDs.  The DB-25 connector also has the Step/Direction signals for X and Z axis if larger motor drivers are required.  In fact, the ELS was designed to be the main controller of your lathe but with the simple swap of the parallel port cable you can temporarily run a full CNC software package like MACH or EMC2.

Features that make the ELS the right choice for controlling your lathe:

        No custom parts like LCD displays or membrane keypads.  Machine tools often have a life measured in decades while high tech companies may last only a few years or even less.  The ELS uses a standard Off The Shelf LCD display with with various options for pin configurations and back lighting.

        Key switches are individually removable and replaceable.  The choice to not use an expensive membrane custom keypad was to make the life of the ELS as long as the machine tool itself.

        The keypad overlay is provided as a laser printable file which can be duplicated using the instructions in the assembly manual.  A worn out or cracked plastic keypad is not a reason to discard the ELS.

        Full source code disclosure under the GPL license.  That means for the life of your lathe or lathes, your product can always be upgraded at no extra cost.  As an example of what goes wrong with closed source for dedicated equipment just trying buying Windows XP for a laptop.  Closed source forces you to choose (if that can be called choose) Vista.

        Not only is the source code freely provided for your education and long term product stability but the schematics and component parts lists are also available.

        A huge user group that has participated in the development of the ELS is there to support and enhance the system rather than a "closed, membership only by purchase" mail list.

        As a kit or partially assembled product, you or your service technician can be assured that there are user serviceable parts inside and that it's not just thrown away if it fails because the manufacturer is out of business.

        The user manual is available for download without any commitment or registration required.  Check it out by downloading it further down on this page to see how the ELS can help you be more productive.

        The ELS is not just limited to controlling a metal lathe.  The on board PIC programmer can be used to install any sort of software customized for a project that needs the above features. With extra connectors access to the RS232/485 and CAN bus controller are also possible.  If you later decide to upgrade your lathe to full CNC control, the ELS can be upgraded to control a different machine in your shop.


Revision 1.00c Ready for production.

Price List:

Electronic Lead Screw Schematics

Click on Green Blocks to view next level as pdf.  Click on clear area to view main page as pdf.  right click and save to download pdf.

Scroll down to get to links for other parts of this project.

Electronic Lead Screw Source Code

Keypad Overlay (pdf)

Here's a photo that shows where the buttons and display go.

Assembly Instructions.

Packaging up the ELS into the Hammond Box Blog


Spindle Optical Sensor to RS485 circuits and photos.

Counting out 35 switches the easy way.

Some Photos

PCB Layout screen capture (Designed with Protel 99SE)



The E-Leadscrew Yahoo group is now

Click to join E-LeadScrew


ELS User Manual

Schematic for wiring up power to the lathe and ELS.