Dismiss Notice
New Cookie Policy
On May 24, 2018, we published revised versions of our Terms and Rules and Cookie Policy. Your use of AstronomyConnect.com’s services is subject to these revised terms.

A Cautionary Undercut Tale

Discussion in 'Eyepieces, Barlows, and Filters' started by Mak the Night, Jun 27, 2020.

A Cautionary Undercut Tale

Started by Mak the Night on Jun 27, 2020 at 8:41 AM

0 Replies 1687 Views 1 Likes

Reply to Thread Post New Thread
  1. Mak the Night

    Mak the Night Well-Known Member

    Jul 10, 2016
    Trophy Points:
    Recently I’ve been testing various 2” eyepieces in some of my 2” diagonals. Most of my diagonals either have a 'Fast Lock' type or are Baader ClickLocks.


    The Fast Lock type has rods or binders inside the draw tube which engage the eyepiece barrel when the lock is twisted. As a further measure the lever itself can be threaded in as an extra safety lock.


    The lighter Baader ClickLock mechanism uses a compression ring type 'collet' instead of rods and has no safety lock.


    The rod binders can be seen in the Fast Lock type below:


    Most 2" eyepiece barrels work in either type. However, my 19mm Celestron Luminos has never been totally secure in the Fast Lock type and required the safety lock.


    Unfortunately when I recently tried the Luminos in the Baader ClickLock it became stuck fast. Luckily this was during indoor weight and balance trials and not outside in the night. I rarely used the Luminos in the Baader dielectric and it was quite disconcerting to have it inextricably stuck in the ClickLock.


    Eventually I had to unthread the ClickLock mechanism from the diagonal housing and also unthread the Smyth barrel from the Luminos. No mean feat considering I am partially paralysed in my right arm and hand. The slight scoring on the Luminos barrel as a result of this activity can be seen in the above pictures. The Luminos undercut is almost certainly the culprit as I've never had any 2" eyepiece stuck in a Baader ClickLock before.
    Last edited: Jun 27, 2020
    Orion25 likes this.

Share This Page