Motorize and computerize your dobsonian scope! This is the Mel Bartels design - do a google search for (free) documentation, software, and construction details.
I built up and tested the electronics and then shelved the project before I finished the mechanical portion, so I'm selling off what I have -
* Populated and tested circuit board w/o field derotator (you could install the required parts yourself if you want field derotation), installed in a project case. Completely wired up and tested. Set up to run on 12VDC. Needs some finishing touches but the electronics are all there.
* 2 TEC SPH-54AB-094 stepper motors (p/n 6454770, 40 ohm, 1.8 deg/step, lot# 2Y19)
* Hand controller with cable.
* Some miscellenous mechanical connectors / bearings / etc you might find useful.
* AST Ascentia 800N laptop to run the (free) control software. 486SX-33, 20MB RAM, 9" color LCD screen, 250MB hard disk, floppy drive, battery charger, and a battery that takes and holds a charge. Has a broken trackball pointer - it's not needed to run the control software at all as it runs under DOS. The trackball may only need to be cleaned. It's a nice small laptop that's powerful enough to run the control software and cheap enough to take out in the field.
I have approximately $250 into this setup, not counting the laptop. Make a reasonable offer (add $20 for shipping) and it's all yours.