I've built several scopes, including my current 14.5" dob with tectron parts purchased back in the mid 90's. At the time there was little choice in spiders and secondary holders as I recall, and I ended up with a straight four-vane model by novak I think. I would rate it as barely tolerable. Very difficult to accurately collimate. The threaded rod with nuts on both ends is difficult to secure without torqueing the mirror out of alignment with the focuser, and the angle adjustment for the secondary is even more frustrating. I've seen the VERY expensive ones from observatory.org, and that's out of the question. Who makes good mid-priced spiders now-a-days for mirrors 8" - 20"?? Thanks!
source for good newtonian spiders and secondary ho
Started by Darvin, 03/15/2009 02:16PM
Posted 03/15/2009 02:16PM
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