Coronado Solarmax II 90 - cannot achieve focus

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aornellas

Coronado Solarmax II 90 - cannot achieve focus

Post by aornellas »

Hello,

This is my first post here on SolarChat. My name is Augusto Ornellas, and I'm an amateur astronomer volunteering at the observatory at the University of Brasilia, Brazil.

Our observatory got recently a couple of PSTs and a big SolarMaxII 90mm. We put them to test a couple of days ago. One PST performed perfectly. The finder on the second one did not work (but it probably has something to do with the rattling noise we could hear when lightly shaking the scope, probably something came loose)

But our main problem is that we were not able at all to get the big 90mm to focus with the provided eyepieces (we tried with the larger one, 25mm). We extended the draw tube to its maximum, even pulled the diagonal to its limit without falling, extended the focuser to the max using the helical focuser, but still it wouldn't come to focus. Then we had an idea to try and verify where the problem was - we loosened the retaining screws on the diagonal and, voilà, we got perfect focus. But for that, the diagonal had to be HOVERING about half an inch behind the drawtube. That is, focus was there, but beyond the reach of all the drawtubes in the scope.

I searched everywhere for someone with a similar problem on the forums, etc, but could not find anything helpful.

Do you have any idea what might be happening to our brand new scope? (well, it's brand new, as it is hasn't been used, but due to customs red tape, etc, it was actually bought at least 2 to 3 years ago. Don't get me started on how much trouble we had to import those scopes into Brazil...)

Thank you.

Augusto


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Re: Coronado Solarmax II 90 - cannot achieve focus

Post by solarchat »

You are probably not extending the main draw tube which is held locked by 2 black nylon screws just where the gold OTA meets the conical shaped black metallic portion that connects the focuser.
Loosen those screws and the large draw tube will extend.


Stephen W. Ramsden
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Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org
aornellas

Re: Coronado Solarmax II 90 - cannot achieve focus

Post by aornellas »

Thank you,

I'll check that out the next time I can. The manual is dismal and doesn't help at all. Looking at some pictures I found now online, that may be the cause. We did extend that large drawtube, but it seems on pictures that it goes much further...

Thank you again.

Augusto


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Re: Coronado Solarmax II 90 - cannot achieve focus

Post by swisswalter »

Hi Augusto

welcome to that wonderful site. Have fun in the sun. You'll manage to get Focus, be sure


Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

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from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)
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