Prior to pulling the plug on new system, a few backfocus questions. According to the spreadsheet; Aluma AC4040 .855" FW7-STX 1.295" Filters (2mm) -.026 (these are the filters available from Diffraction) SC3 guider .870" Aluma CCD/STF/STT adapter plate .147" TOTAL 3.141" QUESTIONS: Are the filters 2mm? Do I need to use the Aluma CCD/STF/STT adapter plate OR no adapter plate OR bolt directly to camera option, OR accessory ring via threads? The backfocus of my existing STL 6303E is listed as 1.7", WITH the black thread block bolted to camera, is this correct? Thanks...
Normally the filters are 2mm. The FW7-STX will also accept third party 3mm thick filters. That's the wrong adapter plate, as that would be for a 2" light path, not 3" light path. The normal adapter is the one that comes with the camera: https://diffractionlimited.com/downloads/STX_Mounting_Plate.pdf Other options here (note the 2: one won't work): https://diffractionlimited.com/product/stx-stxl-aluma-ac-adapter-plates/ The STL backfocus probably includes a nosepiece at that length.
Thank you for your reply. I am thoroughly confused now. Proposed system: Aluma AC4040>FW7-STX>SC3 (short)>PRECISE PARTS ADAPTER>Optec Gemini. I need to get an adapter made from PP. According to Doug, on a previous thread I need to get the adapter made between the SC3 and the Gemini. When I design the adapter, one side is a dovetail to go into the Gemini. The other side using the "SC3 OAG guider thread" option on the PP site, has male threads on it. I need to make sure that this adapter will thread into the adapter that would go on the end of the SC3. I have no idea which adapter, if this makes sense, and need to make sure I get the tight option from PP.
The SC-3 has 4 bolt holes in it. No threads on either side. The AC-4040 comes with 10018 dovetail plate, which has 4 socket head cap screw bolt holes in it. You remove the 10018. Then stack up like this: AC4040 > FW7-STX > SC-3-SHORT > some interface to the the Optec gemini -> Optec Gemini -> Optec 4300 (whichever adapter ring) to your scope -> whatever scope. If you bolt the 10018 where "some interface" is... then you either need a 3.5" dovetail female to put it into, or a 3"x24tpi thread to insert into it, and then from there whatever to get to the Optec Gemini. So that means you would take the 10018 and get PP to make an adapter between it and the Optec Gemini OR Put the 10018 away. Get precise parts to make a suitable 4-bolt to Optec gemini adapter. Might be best if they can do it. more rigid.
This is the drawing for the 10018 mounting plate: https://diffractionlimited.com/downloads/STX_Mounting_Plate.pdf
OK, so I think I have figured this out....adapter that has the bolt pattern of the SC3, other end screws into the Optec adapter from their 4300 dovetail on the Gemini to DSI 3.5" female. That will work. I was thinking that I would use the native Gemini dovetail, but that won't work but with the 3.5" DSI adapter it will. Last question...what is the turn around time AC4040>>>FW7-STX>>>SC3 (short)>>>Filters? Weeks, days. months? Shipping to SE Arizona, US. Thanks,
We have one Aluma AC4040 Class 1 in stock. If you want a Class 1 I strongly recommend you jump on it... the sensor manufacturer has run out of Class 1 and it will be a few months before more are available(!). For Class 2, we're now offering selected sensors that exceed the manufacturer's grading specification. We will be building a batch of Class 2 cameras in the next couple of weeks. FW7-STX, StarChaser SC3-SHORT, and filters are all in stock, though in limited quantities. We're having a little trouble keeping up with demand! We're currently on a cycle where we ship Thursday/Friday each week. If you order right away, before someone else grabs the Class 1, you might make it for Friday... but in any case definitely next week. We use 2-day shipping.
If one forgoes the 10018 dovetail plate and directly attaches the camera to the FW (imaging chain) do you sacrifice the ability to make fine adjustments in CCD alignment? Or are you confident your detector and equipment is perfectly aligned (orthogonal)? I would love to hear "yes" to that answer, of course. Direct bolting is stronger and more stable and not using the adapter makes for less back-focus. But the advantage to the dovetail is making those fine adjustments with copper tape, etc if the alignment is slightly off. I am asking as somebody anticipating purchasing your 4040 BSI system but, like everyone, also hates wasting back focus and would love to direct a couple without adapters. (except to the OTC, of course)
Howard, the "dovetail plate" is removed from the camera when you attach the FW to it. Normally the options are like this: You can also swap it out for a 3" nosepiece. https://diffractionlimited.com/product/stx-stxl-aluma-ac-adapter-plates/ The 10018 plate itself can be inserted into a 3.5" dovetail clamping adapter; you can screw in a 3"x24tpi threaded male draw tube; or you can remove it entirely and use the 4-bolt hole pattern to attach the camera stack to the focuser/rotator. Focuser/rotator -> adapter plate -> camera Focuser/rotator -> adapter plate -> FW-7 STX filter wheel -> camera Focuser/rotator -> adapter plate -> SC-3 off axis guider -> FW-7 STX filter wheel -> camera Focuser/rotator -> adapter plate -> AO-X adaptive optics -> SC-3 off axis guider -> FW-7 STX filter wheel -> camera Focuser/rotator -> custom made adapter plate for the 4 bolt hole pattern -> AO-X adaptive optics -> SC-3 off axis guider -> FW-7 STX filter wheel -> camera The standard 10018 that is mounted on the camera may include shim washers (typically 0.001") if there is any imperfection between the face of the camera body and the plate. Each camera comes with an instruction sheet indicating the position of the shim washers. Since most telescopes have minor mechanical imperfections, if collimation won't take it out, you can adjust the shims.
