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I would be interested to hear as well.
The question of Royce conical mirrors was discussed some time ago here on IIS but it did't come to any conclusion.
Some time ago I was considering buying one to build a lightweight dob but decided against it as the ones I was interested in had the central mounting bolt glued in place which raises a big question about what happens to recoat such a mirror, as glues will outgas in vacuum - effectively foiling any attempt to recoat it.
I don't really accept the idea that overcoated mirrors last indefinitely - especially in newtonians; I have had overcoated mirrors before for many years and they do eventually need recoating. The only exception is a multilayer dielectric coating, but that's serious $$$$ and I don't know if the figure is preserved with such a coating - they aren't thin.
I concluded better to buy a conventional Zambuto mirror made to order for two reasons:
a) I realised actually you DO need weight in the backend of the OTA to put the altitude axis down near the primary. A lightweight mirror (such as a Royce one) isn't such a clever idea.
b) no glue means it can be recoated.
Since then the weather deteriorated to the extent I can't really see any point spending $$$ again in this hobby until I can afford to retire and relocate to a better site; it's a year since my scope has been out of its box for any serious observing and that was so time-limited all I did was re-acquaint myself with the bright things. And there's the long waiting list for a Zambuto mirror...
Last edited by Wavytone; 11-01-2016 at 11:53 PM.
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