Here's my recently completed Equatorial Platform a la Chuck Shaw. It will track for about 90 minutes, which is a wonderful thing for a dobsonian! I just plop my scope right on top and away we go. If you're getting annoyed with constantly bumping your dob to track the planets at high power, do yourself a favor and pamper yourself with this great innovation. Chuck provided me with critical information throughout as I'm electronically-challenged, and not afraid to admit it.
It was very, very reasonable too. The motor was about $25, and the electronics were about $10. About another $5 in bolts, nuts and misc hardware. All the wood was leftover from building the scope $0. Plus the 8 rollerblade bearings were leftover from an upgrade to ABEC-5's a few years ago, cost $0.
To sum up - I LOVE this platform, thanks Chuck!
Serious dew problem this night, the 6v battery and pulse width modulation circuit (riding piggyback on my mirror box) heats my finder and eyepieces with nichrome wire (heating blanket guts) More on the dew heater
Here's a good shot of the drive system, notice the motor is on a hinged chunk of wood which swings up out of the way so I can rewind the platform at the end of travel. A spring holds the motor's gear in mesh with the rod gear
Another good shot of the drive system. Look close to the rod gear and you'll see the end of travel switch that shuts the motor down and sounds the piezo speaker
