I am trying to get a handle on my focuser options with my new EdgeHD 925.
It seems that the Moonlite CHL is very popular with EdgeHDs. The other option seems to be Celestron's Focus Motor (version 2, which is modified to work with the 925 + 0.7x FR). The Celestron option is definitely less expensive at $200, vs. Moonlite ~$900, but the Moonlite minimizes mirror flop and image shift. Build quality of the Moonlite is clearly better. The Celestron option has the benefit of working with Hyperstar.
But I am coming to the conclusion that Moonlite CHL would NOT work w/ EdgeHD 925 + 0.7x FR + COAG, due to it taking too much of the 146mm backfocus. Am I correct?
I have not seen definite effective lengths for all of the parts of the path but here is my initial assessment, assuming the Moonlite at mid-range of its 0.7" range:
The most flexible arrangement, allowing both DSLRs and astrocams, needs 55mm between the sensor and OAG's exiting adapter. The tightest I would consider would allow a 17.5mm deep camera + EFW, so ~38mm at the thinnest.
Moonlite CHL at minimum, 2.5" ~64.0mm
Moonlite CHL mid-range, 0.35" 9.0
OAG input adapter ??? 4.5 (assuming COAG Female M48 Telescope Adapter)
COAG body 29.0
Male M48 Camera Adapter 12.5
Give the EdgeHD 925's 146.05mm backfocus distance, this leaves only 27mm. I could pick up a couple of mms by racking in the focuser from the mid-point, but I would still was some extra inward range. The Moonlite could just barely work for my ASI183mm-Pro+EFW, but takes up 11mm too much length to be able to fit a deeper camera (such as ASI2600+EFW, still wishing for mono version), much less than allowing a DSLR. The Moonlite could work for a ASI2600MC or ASI071MC, without the need for the EFW.
So it looks like for a EdgeHD 925 + 0.7x FR + COAG, Celestron's Focus Motor is the best option.
Am I missing something?