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Old 20-11-2013, 08:07 PM
glend (Glen)
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glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 7,121
After another night with lack of in-travel to achieve focus on the higher magnification eyepieces, I went ahead and replaced the stock springs and the adjustment bolts and locking bolts - on the basis that this will allow the primary to be moved upward enough to achieve good focus range of travel, and hold the mirror securely. I got tired of trying to find that sweet spot where the bolts still held the mirror carrier (without clunking around) and I could use my higher magnification EPs.

I chose the Century C-792 springs (from a Bunnings that stocks them) cut them in half and they still provided 10mm more un-compressed length (at 40m) and a stiffer spring overall, and the adjustment bolts were changed to M8*50mm (an extra 7mm of length), locking bolts to M8*50mm. These bolts were a test setup and they seem to work fine, with lots of range, so I will try to find some M8 star knobs of that length.

This problem needs to be addressed by GSO back at the factory.

Testing again tonight, will report back.


Update on last night's testing - the scope is now perfect.

Star test was great right through the EP range, and focus achieved on all EPs right to 300x (6mm). Tried it out on a range of DSOs and the collimation held true through all angles of altitude, including the Orion Neb at very low angle just above the trees, and this was a problem with the stock springs.

All good.

Last edited by glend; 21-11-2013 at 10:33 AM.
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