Sp@ce_ing Why so difficult!

[Sp@ce_d]

So... I've just ordered my first CCD.. the 314L+ & EFW2 & already my head is hurting trying to work out what I need to achieve correct spacing on my scopes. If I want to use it with the reducer on the 80ED then I need 55mm. Having had a trawl through posts it's clear this is not straight forward... why?

Atiks 314L+ manual quotes 12mm from sensor to faceplate.. yet others on here say its 13.1mm. Then there's 1mm to take into account for filter thickness?? I can't even see the spacing mentioned in the EFW2 manual.. is it 22mm? Then there's the M54 adapter.. 1.3mm? God help me if I wanted to use an OAG!

I wondered about using a variable spacer like the Baader varilok system but that seems to be a minimum of 20mm I "think I'm looking somewhere between 17-19mm?... seems like a hacksaw job!

Anyone using this settup have the answer?