Orion AZ-3 Alt-Az Mount
Posted 10 May 2011 - 03:15 PM
Posted 10 May 2011 - 04:25 PM
Posted 10 May 2011 - 10:03 PM
The overall performance was excellent, considering how inexpensive the mount is.
Moreover, the performance of the scope can be improved if you balance the tube at a 60* angle and not horizontally.By doing so , the vibration is reduced even further.
In addition, an even better solution would be to come up with a reversed L shaped bracket and mount the scope parallel to the central axis of the altitude gear and NOT atop,which is the current set up.
I'll try to get some pictures I had seen years ago and get back to you.
Posted 11 May 2011 - 09:59 AM
Posted 11 May 2011 - 01:00 PM
These mounts are very poorly suited to Astronomical use.
The problem is that the altitude axis really isn't designed to be used with a telescope pointed higher than about 30 or 40 degrees in elevation.
The problem manifests itself in the tendency of the scope to "Cascade" back when you point it to higher elevations.
As you tilt the scope back, the center of gravity moves behind the head. This puts more pressure on the altitude friction washer, and the axis will start to creep.
You can tighten up the nut that changes the pressure on the axis, but when you do this, it makes the mount very stiff.
Generally by the time you get the nut tightend enough to hold the scope at all orientations, it becomes too stiff to move easily.
I OWN one of these, but I use it 100% for birding and terrestial (C5 mounted on it).
I tried using it for astronomical purposes before though, and did not like it at all.
I think you would be far better served by going to one of the new mounts that are specifically designed for astronomical use. These ususally have standard dovetail saddles (which is good for balancing) and pivot though the center of the OTAs longitudinal axis. No problems with creep when the scope is balanced.
So, just my opinion, but I think you can do FAR better than an AZ-3 for astro use.