DIY telescope remote and autofocus project
This project began as a reproduction of a remote focus motor published on the internet by Brian Sumpter(thank you!) (here). A 'gutted' servo controlled by a DPDT switch to reverse polarity (and hence direction) with a potentiometer to adjust the speed. That was quickly followed by modifications like a PWM supply and an H-bridge for better speed control in both directions. This worked great but lacked 2 important desires....
1) an interface that matches the movement of a focus knob
Both of these have been achieved (see Pictures and Videos page) in a very easy to build, inexpensive design, by utilizing a Pololu Maestro 6 channel servo control board coupled to a stepper motor via an H-bridge. Movement is accomplished by turning a rotary encoder. Autofocus by 'homebrew' C# code. The mount, made from aluminum stock purchased at a local hardware store, is attached via the finder scope bracket.
The lastest version now uses and Arduino Uno control board, a pololu A4983 stepper driver and a much larger 6volt stepper motor. It still functions as a stand-alone unit for visual use, and can be controlled via a modified version of the home built C# autofocus code.
The software has been significantly updated to utilize a method that eliminates the need for backlash compenstation(adapted from the FocusMax paper here)
Note the flexible motor shaft coupling in the picture....
******* If you just want to try it out with your Arduino setup *****
I have also added a bare bones version of the Arduino focuser (here: Arduino Focuser 2) that does not use a keypad, LDC or rotary encoder and will work with any ASCOM compliment software.
Also check out Sound Alert a simple program that sends an email when your computer makes an alert sound. Designed to be used with PHD and send a text message via email for lost guide star.
Inside the Box....
Original version with manual focus via rotary encoder, keypad, LCD display and dual stepper drivers for Orion filterwheel modification.