Alex
Sorry to hijack, but what's the solution to the issue of secondary adjuster screws gouging the secondary. Mine has a metal plate at the back of the secondary. But I can still see some marks on the plate from those screws. Smooth filling the ends of the screws?
Chris
Quote:
Originally Posted by mental4astro
Hi Mike,
The issue would seem to be the secondary mirror is not held securely in place. It would be the only reason for the wandering red dot.
Two causes for this:
1, Could be because the sec. collimation screws are not all pushing against the secondary holder.
or
2, There is too much play in the thread holding the sec screws in place, the spider hub, so when the scope is moved about, the play in these threads is allowing the secondary to move about under its own weight.
What does not help this second point is that these collimation screws have a sharp round tip that pushes against a soft plastic secondary holder housing. Of if is is metal, it is soft aluminium compared to the steel screws. In either case the holder housing is being gouged by the collimation screws, forming pits. These pits will make the collimation process less stable for the secondary, and allows the secondary to move about under its own weight because these pits allow the collimation screws to also move because of the play in the spider hub.
If it was a loose primary mirror, the movement of the dot would be more of a jolt than a gradual shift.
Alex.
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