Installing the Howie Glatter Sling

On May 4, 2023, I ordered the Howie Glatter Cable Sling.  The Howie Glatter sling is a new support for the primary mirror of my 18" Obsession.  It has a few advantages over the standard Kevlar sling:
  1. Stability and Consistency: The main advantage of the Howie Glatter Cable Sling is that it provides stable support for the primary mirror, because the cable sling doesn’t stretch or slip off the mirror.
  2. Equal Mass Distribution: The cable sling has equal mass on both sides of the cable, which helps to reduce astigmatism. By maintaining balance, the cable sling minimizes any distortions caused by uneven weight distribution.
  3. Edge Support: The Howie Glatter Cable Sling restrains the mirror to its lowest equilibrium position, eliminating sideways miscollimation.
  4. The Howie Glatter sling ensures better collimation and overall performance.
  5. The edge support ensures that the mirror remains properly aligned during an observation session.
The Howie Glatter sling arrived on September 25, 2023.  It took a while to install everything.

One of the most important things to know before installing the Howie Glatter sling, is the Center of Gravity of the mirror.  This can be calculated by the Mirror Edge Support Calculator.  For my 18" Obsession, the Center of Gravity is at 23.45mm from the back of the mirror.

The installation process was not so difficult, but it is important to take your time for each step (and to read the installation instructions a few times before starting).  The rest of this post shows some pictures of the installation process.

The original Obsession Sling installed in the telescope.

The removed Obsession sling.

First part installed.

The new mirror bumpers.

The disassembled old mirror bumper.

The assembled new mirror bumper, before installation in the telescope.

The installed new mirror bumper.

The velcro strips just above and below the Center of Gravity of the mirror.

Comments

Popular Posts