The Vixen Dovetail Plate System

Vixen Hardware and Specifications

 

An astronomical telescope is made up of two basic components including the optical tube, which determines what one may see, and the equatorial mount which determines how the telescope may be used. Getting these two items together has not always been easy, but quick release hardware sure makes it easier than ever before.

Left: Rigid Saddle of the 1980's Vixen Super Polaris Series German Equatorial Mount.
Note two captive ¼ inch 20 tpi attachment bolts which secure the telescope mounting rings (not shown) in place.
This was arrangement was typical of most German Mounts into the early 1990's (28,098 bytes).
Click on image to see enlarged view (92,256 bytes)

Up until the late 1980's most telescopes were installed onto Mounting Rings which were usually bolted onto the mount Saddle - the flat area on top of the Declination axis of an German Equatorial mount. This took a little time and some luck particularly when trying to match up a hole pattern and installation bolts in the dark. This arrangement kept the spacing between two rings fixed, often a bit too close for some with longer, torque inducing telescopes. And if the Mount fell over, then the protruding Saddle tip could be broken off rendering the mount unusable until repaired.

By the end of the 1980's quick release hardware became more common. It was popularized by companies including Losmandy and Astro-Physics which Company Seven continues to offer. When Vixen discontinued their previous "Super Polaris" series mounts and announced the current "Great Polaris" (or GP) line, one of the notable improvements was the incorporation of quick release hardware. The quick release hardware includes two basic components:

1. a male dovetail plate, a metal plate usually of two or four inches in width with lengths of between six to fourteen inches or more
   

2. a female plate (or saddle) onto which the dovetail plate slides on lengthwise, or slips in sideways and settles flat. The saddle incorporates at least one, maybe two hand knobs which are tightened to secure the dovetail plate in place.

Right: Diagram of Vixen SPHINX SX and SXW German Equatorial Mount Hardware (38,221 bytes).
Click on image to see enlarged view (69,183 bytes)

The telescope mounting rings are now bolted onto the dovetail plate. On some plates, the mounting bolts protrude below the plate and act as safety stops to keep the telescope from sliding off the mount if the saddle is accidentally loosened. The advantages of the quick release hardware include:

• the Mount Head can then accept any accessory that is attached to a compatible dovetail plate,
• quick and simple changing of optical tube position, or easy removal of the OTA and installation of another in its place - all with out the need for any tools,
• some dovetail plates are so long so that an attached telescope may be moved forward or back on the saddle to better balance it along the Declination axis,

Vixen Hardware and Specifications