Quote:
Originally Posted by erick
Fit JMI and insert laser. Adjust grub screws to have laser strike - where?
Or ignore all this entirely - swap over the focussers then worry about the location of the focusser relative to the optical axis by other means?
Advice welcome - thanks Eric
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Hi Erick, I have a fair bit of experience now on this one both in Newts and SCTs. After having pulled everything apart. The focuser barrel/draw tube in my case was a problem. To check if the focuser mechanism was square in itself I spun it on a turn table and shimmed it until it was acceptable. Then for the SCT I stuck a collimated laser directly screwed in the mirror cell and removed the secondary. Check the red dot reflection on a wall while spinning the entire OTA. Shimmed the adaptor ring. When happy with that I did the same with the laser inside the focuser. Once you have that working secondary adjustment is only part of the standard collimation process.