Second Hand SCT Maintenance and Modifications

[stuffedhaggis]

Hi All,

 

I have just purchased a 8" Sct. Are there any good Maintenance tips I should look out for ?

Also any good mods ?

[Pig]

Hiya there Haggis,

A dew shield is a good addition if you do not have one as the SCT's are a bit of a dew magnet and not having one can dramatically reduce your observing session, the standard focusers are a little stiff so you may want to get a different type IE a Baader Steeltrack Crayford dual speed.  A good tip is to try and resist cleaning the corrector plate as this is where the light gathering coatings are applied.

I think most of the mods in this forum are a little suspect ..... is that what you meant ?  

[stuffedhaggis]

6 hours ago, Pig said:

Hiya there Haggis,

A dew shield is a good addition if you do not have one as the SCT's are a bit of a dew magnet and not having one can dramatically reduce your observing session, the standard focusers are a little stiff so you may want to get a different type IE a Baader Steeltrack Crayford dual speed.  A good tip is to try and resist cleaning the corrector plate as this is where the light gathering coatings are applied.

I think most of the mods in this forum are a little suspect ..... is that what you meant ?  

Great thanks for the advice.

[Ikonnikov]

I would second the use of a dew shield, I found this essential for my C8 and also a dew heater strip behind the corrector plate for most of the year (does depend slightly on the humidity your location I believe but I rarely got away without needing at least some heating).

The feathertouch SCT microfocuser is also a good addition as it allows much finer focusing and seems to reduce the mirror flop and image shift associated with SCTs when fitted. Also it reduces the need for an additional focuser on the visual back although this is probably still a good idea for high power imaging.

Many (most?) people seem to replace the secondary mirror collimation screws with Bob's Knobs to make collimation more convenient, I certainly found them helpful.

For deep sky imaging a focal reducer is pretty-much essential as the slow F ratio and poor correction of off-axis  aberrations does not make for easy or pleasing images (ignore for the latter for Edge HD versions) ! The F6.3 is also used for visual to give wider field views although the maximum FOV is quite limited by the narrow baffle tube of the SCT design.

 

Paul