My astronomy project:
TS130 refractor to Nikon D800 adapter

Content:

1. TS130 to Nikon adapter
2. Adapter prototype
3. Implement of a duo narrow filter
4. Preparing for first light
5. Aberration analyze
6. Shorten the adapter length
7. Adjust tilt and back focus
8. New bracket for guide camera
9. Baffles
10. Prism bracket
11. RayTrace advanced
12. To be continued

Note:
I take no responsibility or liability for what are written here, you use the information on your own risk!

6: Shorten the adapter length

With the knowledge I got from the aberration analyze it must be that the adapter is far too long. It must be that the figure 106 mm back focus is correct, not the 116 mm. Back to the CAD design board and shorten the adapter, this time I 3D-print it with 0.1 mm layer height.

The new adapter to the left, 11 mm shorter. The outlet to the off-axis guide camera is moved 1.5 mm away from the main camera sensor. Just to let the 2" duo band filter fit. Later if it work as expected I replace it with a 50 mm unmonted filter, increase the opening from 44 mm to 48 mm. It will reduce the vignetting.

To make it easy to adjust the length of the adapter and the tilt the joint is hold in place by three springs and screws. The spring's force is strong enough to not let the cameras weight change the position. The spring sits in a 4 mm deep hole.

The slit between the adapter's two parts, later I adjusted it to be 2 mm for a first test. The adapter is 3D-printed in a new material with a black matte surface, Dunkel Schwarch, still PLA. Looks good but the M80x1 mm thread wasn't as good as when I used the standard PLA material, it took me two hours to clean the threads.

Installed on the telescope, I have adjusted the prism for the off-axis guider to 13 mm away from the optical axis. The sensor's edge is 12 mm from the optical axis. Ready for a test first clear sky.