This is a page about the Night Sky Scopes' 16 inch telescope that Sidereal Technology adapted for their trade show use.
Click on the picture for a larger picture.

In this photo, you can see the complete telescope.  You can see all the electronics and drive mechanics.

16 Inch Whole Thing

In this photo, you can see all the electronics and the mechanical clutches.
The telescope encoders are mounted on the drive shaft of the gear reducer/clutch assembly.  This is a neat idea, because the encoders can be geared up for much more resolution, and they are readily accessible.  It's important to understand this concept.  The belts don't slip around their drive pulleys, the altitude can't because it's pinned.  The azimuth doesn't because it has non-skid.  This means the shaft going through the clutch mechanism turns several times when the telescope turns only once.  Now the encoders provide super resolution.  The controller itself is interrupt driven, so pulses will never be missed, even at high speeds.  The number of encoder ticks for each revolution of the scope is programmable.

Be sure to click on this picture, as you will be able to see many details.  

Here's the altitude drive.  Notice the belt holding spring.  This is a cool idea, 'cuz the belt will never slip, and the tension is always set!
Altitude Pulley

Most scopes use the center pin for the azimuth encoder.  We've have a hole drilled through the center bolt, and we've run the serial cable down through it!  Cool idea eh?  The Azimuth Encoder is on the clutch mechanism!  If you zoom in on this photo, you'll notice the "non-skid" glued to the surface of the azimuth disc.  We didn't seem to have a problem with belt slippage before we put the non-skid on, but we wanted to be sure.  The white plast pieces keep the belt from falling off, although, I doubt if we would have a problem with that anyway!
16 Inch Underside

If you want to have a clutched system, then you'll need to put in ball bearings on your altitude and azimuth.  We've designed a low profile dual bearing which makes this a snap.
Here's a picture of the altitude bearing:
Altitude Bearing On Scope

Here's a photo of the dual bearing assembly:
Altitude Bearing Assembly