backfocus consumed by celestron diagonal adapter plate 11SCT-A00-7 on edgehd 11? Related to oag setup

[theskyisthelimit99]

I've searched high and low but cant find the answer on this one.. I believe the rough estimate is actually 9mm but cant find confirmation.

this is the part:

 

 

Trying to work out the math to see if im at 146.05 or so (plus or minus 0.5mm), from a rough caliper measurement i "think" im dead on but the math doesnt add up when i add up all the parts, for instance here:

 

start:  F7 reducer threads end 
9 SCT adapter plate??
25.4 blue ball spacer
25.3 celestron sct adapter
29mm body oag
12.5mm male 48mm adapter
17.5mm starizona drawer
1mm filter
11mm ring on asi294mc
6.5 to sensor

Finish: asi294mc pro

137.2 (so short by this definition but by rough measurement with everything attached and guestimating threads of f7 end in the ring of the adapter, i'm at 146) My guess is that the celestron oag sct adapter at 25.3 is not the right value (i should measure it direct to confirm)

Thanks for any input /info

 

Edited March 18, 2021 by theskyisthelimit99