# Motorize Your Telescope:

# altazimuth and equatorial mounts

### ...by Mel Bartels

software last updated June 23, 1999

briefly:
- Get two surplus steppers (5 leads or more) and two small gear reducers of about 50:1
- Switch teflon pads to small bearings
- Replace formica bearing surfaces with sheet metal
- Make one of the bearing points in each axis a small drive shaft that is attached to the small gear reducer
- Get the circuit board and electronic parts
- Make the handpad and hook up the components
- Get a cheap pc or laptop
- Get optional encoders and encoder interface box
- Configure for your particular combination of parts
- Total cost ~$300 - $500 (see how others have done it by visiting the links below)

## printed circuit boards now available (populated and unpopulated)!!! click here for details and latest construction notes

- click here for Spanish version
- the ultra light computerized motorized 20 inch
- an unguided exposure of M13 using Richard Berry's cookbook245 camera...

## Table of Contents

- Why Motorize a Dobsonian Telescope?
- Features
- Mechanical Aspects of the Drive
- Stepper Motors
- Circuitry
- Field Rotation
- Parts List
- Parallel Port Interface
- The Software
- Optional Encoders
- Autoguiding
- Configuring the Software
- Operating the Software
- Software Update and Bug Fix Log
- Contributors
- Special Modifications

## Download Software

- download the executable program (1999-6-23 100kb)
- download the associated data files (1999-6-9 70kb)
- download webpages (1999-6-23 90kb)
- download circuitry graphics (1999-5-8 420kb)
- download scope graphics (1998-9-28 200kb)
- download the source code (1999-6-23 90kb)

if you have trouble, e-mail me and I will e-mail you back the files

## Links to and pictures of other amateur computerized newtonians

- Al Fressola's motorized dob
- Allan Rahill's motorized 22"
- Berthold Hamburger's PCB for the motorized dob
- Big Blue - a german equatorial computerized scope
- Bill Fries computerized dob
- Bill Prewitt's computerized 12"
- Botter's Thailand computerized metal dob
- Chuck Shaw's 14" motorized dob with excellent detailed notes on construction and fine tuning
- Dirk Dhoore's computerized dob webpage
- Don Halter's 16" dob converted to computer control
- Eastern Missouri Dark Sky Observer's 30"
- Greg Granville's motorized dob web page
- James Krushlucki's Basic program that uses the stepper drive circuit to track an equatorial scope in R.A.
- twin Spanish automated 14" Schmidt cameras, graphic by Jaime Nomen
- Jay LeBlanc's 17" motorized dob
- Jerry Pinter's 13 inch motorized dob construction notes plus astrophotos and CCD images taken through the scope
- Paul Shankland's computerized 16" webpages
- Petr Malon from Praha Czechia computerized cassegrain
- Rick Iwanika's 6" f/4 computerized equatorial
- Russell Crow's 18" computerized equatorial, made from surplus material
- Alphonse POUPLIER's computerized drive webpages
- Victor Trombotto's unusual computerized observing arrangement (Argentina)

- goto Mel Bartels' home page with more articles and many more links
- send e-mail to Mel Bartels

## Further Information

- Microelectronics Industrial ICs - stepper motor application notes
- floppy drive steppers
- stepper motors controller
- Jameco stepper driver kits
- Jones on Stepping Motors
- Stepper Motor Basics
- Stepper Motor Introduction with lots of links
- Tony Mercer's Basic Stepper Motor Concepts
- Electronics page
- Electrical enginnering circuits archive
- FC's electric circuits
- Electronic schematics
- Motion Control
- Motion Online
- TERN Inc, single board computers
- Intelligent Motion Systems
- Laser and Motion Development Company
- Oregon Micro Devices
- Performance Motion Devices
- Precision Motion Control
- CCNC homepage
- NeuRobotics Lab: RoboLinks
- Robotics Automation parts
- Mechanical Parts Sources - vendor listing of gear reducers, bearings, and other parts, for PC based motion control systems
- Clear Sky Institute - robotic astronomical control software for linux
- robotic telescopes at Fairborn Observatory
- Bolton's Group Computer Controlled Telescope using PC-PCS by Dave Harvey of Comsoft
- CTC (COAA Telescope Controller), a low cost Portugese unit for equatorial mounts with stepper motors ala a GP
- Deep Space Navigator DSC and dob driver
- Tech 2000's Dob-DriverII, a commercial altaz drive system
- SkyProbe 1000, a commercial altaz drive system
- Quadrant Engineering, a commercial drive system

Build Your Own Low-Cost Data Acquisition and Display Devices by Johnson, publisher Tab
Microcomputer Control of Telescopes by Trueblood and Genet, publisher Willman-Bell

## Disclaimer

Feel free to contact me with questions. For the code, please send an SASE floppy mailer. Over my 25 years of amateur astronomy I have been helped by several ATM experts who graciously gave of their time and hard won knowledge. In the same spirit, the information from this project is being offered freely. You may use it in any fashion that you wish. Crediting me would be nice!
Mel Bartels
1294 "B" St.
Springfield, OR 97477 USA