WO FLT110 lens cell issue solved

OzRob (Rob) · #1 23-02-2010, 03:19 PM

I am posting this just in case someone else finds the same problem.

I had noticed that on some nights my stars were deformed. It appear that there was an in focus image of a star merged with an out of focus image of the same star (see the attached image.) The alignment of the two was the same across the whole field of view.

What I found was that the lens cell was not tight and I assume it allowed some slop. After tightening the cell the issue was resolved and I am sure that the stars are tighter than they have been in the past.

UniPol · #2 28-02-2010, 02:33 PM

Rob,

I have found that a number of my WO lens cells, namely the FLT132, FLT110 and Z66, came loose over a period of time because the dew shields may be slightly tight when sliding the shield in or out. My usual action is to hold on to the tube and use a twisting motion on the shield to move it in or out. If you just pull on the shield you feel that you'll pull the scope over.

If, over a period of time, you turn the shield anticlockwise then the cell may undo very slightly each time. I now turn or twist the shield clockwise to overcome this problem.

Some manufacturers use a small grub screw to stop the lens cells from unscrewing however to the unwary, a lot of damage can be done to the tube threads and cell threads if you try to remove it.

You WO guys and gals out there may wish to see if your lens cells are loose also

Cheers,

Steve

Geoff45 (Geoff) · #3 01-03-2010, 02:18 PM

Be aware of big danger here! I have a WO zs110 and I presume the lens mounting is similar to the FLT110. The other day I wanted to remove my dew shield. Started unscrewing it from the retaining ring at the bottom and pulled it off. As mentioned above, this can cause the lens to unscrew and it did. Lens was sliding down the dewshield towards the floor. Luckily I caught it!
Geoff

OzRob (Rob) · #4 02-03-2010, 02:13 AM

Geoff, I bet your heart was in your mouth...lol

I doubt that twisting the dewshield on my scope would loosen the lens cell to a great extent as it is fairly stiff to turn. Certainly something to be careful about and I will be checking mine regularly.