If you have a Celestron SE, Evolution or CPC mount and want to use it with a camera and the Celestron 6.3X focal reducer you will need a way to avoid the camera crashing into the mount as the optical tube approaches zenith. Below are 4 different configurations I have detailed along with all of the parts needed to enable reaching zenith without crashing into the mount. These are all parts that I have purchased and confirmed work. Links are affiliate links which means that I can earn a small commission which helps defray the cost of this web site. If you have questions on these or other products email me at email@example.com.
The Celestron 6.3X focal reducer requires a back spacing, that is the spacing from the back of the focal reducer to the sensor in the camera, of 105mm. The spacing is measured from the back most surface of the focal reducer. I have outline 4 solutions below with the parts needed in each case. Links are provided for my two preferred astronomy equipment vendors, Agena Astro and HighPoint Scientific. Just pick the setup you want and the vendor you prefer and use the links to assemble the entire back focus setup you need.
Agena Astro Links Baader Ultra-Short SCT F to T2 M Adapter bit.ly/47qmoJ0 Baader T-2 90-deg Prism Star Diagonal bit.ly/3POOSVv Blue Fireball 18mm Extension bit.ly/47tE7zm SVBony 24-35mm M42 Variable Extension amzn.to/3ME1azA ZWO M42 Female to Female 11mm Adapter bit.ly/3QSoqfE You could substitute the Baader Varilock 46 T2 Variable Extension bit.ly/3rztlZb for the Blue Fireball 18mm & SVBondy 24-35mm if you want less components
HighPoint Scientific Links Baader Ultra-Short SCT F to T2 M Adapter bit.ly/47Tz4s4 Baader T-2 90-deg Prism Star Diagonal bit.ly/4a1QX9Q Apertura 10mm Spacer bit.ly/47CQHwx SVBony 24-35mm M42 Variable Extension amzn.to/3ME1azA ZWO M42 Female to Female 11mm Adapter bit.ly/49YFeZI You could substitute the Baader Varilock 46 T2 Variable Extension bit.ly/3Rpf77f for the Apertura 10mm and SVBondy 24-35mm if you want one less component
Alternatives to the SVBony 24-35 Variable Extension Blue Fireball 18mm Extension bit.ly/47tE7zm + Blue Fireball 6mm Extension bit.ly/478vJFs Optional Components to Vary the Back Focus Spacing Baader T2 Delrin Spacer Ring Set bit.ly/49yhbko Blue Fireball Additional Spacers bit.ly/49tNReL