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:


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)



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ELS User Manual

Schematic for wiring up power to the lathe and ELS.


Links to the people who have contributed hardware to the project.

Although Ohmikron has discontinued this product Automation Artisans would like to thank them for their help and support.

Ohmikron BSD0906 and PPT1006 donated to project and tested with ELS.  (Discontinued)

AVR_STMD Stepper Motor Driver donated to project and tested with ELS