Rotary Controller


What is it?

It’s a device that allows easy, error free indexing using a modified rotary table, dividing head or similar

Written by a software engineer with over 40 years experience, the controller has a sophisticated interrupt driven motion engine featuring smooth linear acceleration and handling non integer steps correctly meaning you can be confident there are no positional errors.
It’s in continuous development and benefits from 16 years of feedback from many thousands of happy users.
Full support is given whether you buy a fully built unit or opt for self build.

As well as division the controller allows movement by angles (0.01 to 360 degrees), continuous motion (for machining), positioning (jog mode), a simple gear cutting mode and a sophisticated program mode which allows complex sequences of movements and events to be executed.

Input is via a 16 key keypad whilst a 4 line by 20 column LCD display provides information in a user friendly format. 

For example to cut a gear with 127 teeth (a prime), press the [2] key for division, enter 0,1,2,7 and press [G]o.
Now each press of the [<<] or [>>] keys will move the table by exactly 1/127th of a circle.

In a typical application a Nema23 stepper motor is mounted on the rotary table/dividing head using the existing dividing plate screws via an adaptor with a suitable coupling between the motor shaft and the table shaft.

How do I get one?

Ready Made

I offer a ready built unit.
Built into a CNC cut diecast case, it has an internal 5.6A stepper driver and comes with a prewired plug with 2m of cable to connect to your stepper motor.
It also provides a socket for an external driver which can be selected instead of the internal driver on a per profile basis.

Requires a readily available 24v 4-6A ‘brick’ style power supply with a 5.5mm x 2.5mm plug.

Ready Built Modules

I can provide both the controller module and keypad for use in your own case.

These are complete and tested. Connections are via screw terminals and the device requires a 12-32v supply @ 50mA (usually the same supply as used for the stepper driver is used).
Only 3 wires are needed to connect to your stepper driver. 

Will work with most 3rd party keypads. If used with my keypad an optional commercial produced overlay can be purchased from me for that professional look.


All the necessary information to build your own divider is provided in the downloads section of my site.
This includes the latest version of the firmware for the controller.

The device can be built on stripboard or I can provide a PCB and/or a ready programmed PIC.

Parts are easily available and none critical.