Customizing Commercial Telescopes

I have a few homebuilt telescopes using commercial components (6" Jaegers f/5 refractor, 4.25" f/4.1 reflector with Edmund AstroScan Optics, and a few others). Over the years as an idea hit me that I wanted to incorporate into these scopes - as an example I just added grab handles to the focuser of the 6" f/5, I did it without a second thought. On the other hand, I am very hesitant to modify any of my commercial scopes - Takahashi, Celestron, Brandon, feeling that a modification, especially one involving change that cannot be undone will destroy the potential resale value of the equipment. Any discussion on this?

As always, "it depends." The XT8 I bought in January, for instance, was a good buy. Collimated, a center dot added to mirror and a Telrad put on -- which obviously isn't too severe as customizing goes. I'd be worried mainly about any apos you might mess with (you mentioned Taks), which seem to hold their value better than reflectors or sct's. On the other hand, if you find some modification to come in handy it's a fair bet someone else will, too. I read a review on Cloudy Nights the other day about a replacement focuser for Meade LX-series sct's, and since I once had one, it sounded like an improvement to me. If I had an expensive apo, though, I'd probably think twice before doing anything. Just MO.

/John