FreeLists / az-observing / [AZ-Observing] Bausch & Lomb

[Stan Gorodenski <stan_gorodenski@xxxxxxxxxxxxx>]

Probably about 10 years ago I bought a 4" f/12 Bausch and Lomb 
catadioptic (I do not know the actual configuration, but it does have a 
meniscus with the secondary attached to it) telescope at the swap meet 
at RTMC. It never has given very good images which is probably why it 
was being sold. Although the images may not be good for astronomical 
stuff, it should be good enough to align everything on my 12.5" 
Dall-Kirkham after taking the mirrors out for cleaning.

I discovered the secondary image was off center quite a bit when looking 
through the back end of the telescope. I got it fairly centered by 
adjusting the secondary allen screws. Then I discovered the whole 
meniscus-secondary assembly moved in the cell quite a bit if I lightly 
pushed on the secondary housing. When I went to tighten down the large 
treaded ring, the rubber spacer between the ring and the meniscus 
started squishing out. I popped it back in place, and in the process of 
doing so I discovered it is sticky and a somewhat slimy. Thus, probably 
if I set the telescope on its side, the meniscus-secondary assembly will 
slowly drop down with the result that the telescope will again be out of 
alignment. If I try to prevent this by tightening down the large ring 
even more, then the rubber spacer will start squishing out.

Questions: Could this easily be corrected by discarding the rubber seal 
and cut out and put in a spacer made of thick automotive gasket 
material? Is there another solution someone may be able to suggest?
Stan

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