Azimuth Drive Design
Over the holiday Larry and I have been keeping an active dialog on the drive design for both the azimuth and the altitude. I think we’ve been through a number of iterations and have continued to make adjustments, but here is what we have so far. This “ghosted” image lets you see through parts that would otherwise be hidden in a regular shaded view (see below) and this view gives you a picture of how it is situated in the overall design. On the left bottom is a one of the piers (North, not that it matters). Sitting on top of the pier is one of the famous McCune rocker bogeys – there is one on each pier. Riding on top of that rocker bogey is a large radius ring which is the azimuth bearing surface that is mounted on the underside of the base of the telescope (not shown).
Just to the right of the pier, and attached to one edge of the base of the rocker bogey assembly, is the azimuth drive assembly. The large cylinder is a wheel out of a catalog solid mounted to a 0.500-in shaft connected to the BBAstro drive and gear box (in turquoise on the back of this assembly). When the wheel turns, it drives the azimuth bearing surface and the whole telescope turns about the center pivot of the scope, also not shown here. Notice the hinge on the bottom left of the box that holds the gearbox and the drive wheel and shaft – with that hinge, and the bolt threaded through the base of the box, you can adjust the pressure of the drive wheel against the azimuth bearing surface.