Final version of Canon FD 300mm f2.8L with NGF-CM

I reprinted the adapter with a longer nosepiece to avoid misalignment due to the setting screw hitting the grove.  This new one is printed using PETG with carbon fibre.  To do this, I have to use stainless steel nozzle but it's still difficult.  

The first one failed in the middle, since the supporting structure collapsed during the print:

It's so bad that I have to cancel the print, wasting quite a lot of filaments.

I did a atomic pull to clear up everything, slow down the print as advised by Gemini.  It did help but some of the supporting collapsed too:

Since I kept a close eye on the printing process (3.5 hr!), I am aware of the issue before it's too late.  Pausing the print and ask Gemini again, I trimmed the hairy part so that it won't hinder the nozzle movement.  But the lost of some supporting part will be a trap for closing the ceiling.  Gemini suggested to use masking tape to replace the lost support:

Gemini said it's valley of death!  I slowed down the printing of the ceiling to 40%, and it closes sucessfully.  The new adapter was printed nicely.

No more misalignemt issue with the longer nosepiece before the grove, another issue was found about squaring the focuser.  It could be adjusted by the fixing screws on the NGF-CM.

This is another hobby altogether.  I mean DIY of equipments.

Frustrating sometimes but lovely at the end.  I will test it out shortly.  Dark night is getting shorter and shorter.