I sent an inquiry about this through the Diffraction Ltd website "Contact Us" platform, but I thought I would post it here as well. I am trying to build a custom adapter to attach my STXL16200 camera with self-guiding filter wheel to the male 2.74 - 24 threads on an Astro-Physics 92 mm Stowaway 92FF field flattener. Precise Parts claims to be able to make such an adapter, but I am suspicious about some of the dimensions, so I would rather not go that route if I can avoid it. I have been burned by them on more than one occasion. From the research I have done, it looks like the best option for an adapter would be if I could get a modified version of the OEM faceplate that came with the camera. Please take a look at the attached sketch. It is essentially an exact copy of the OEM faceplate with the alternate dimensions shown in red. If you think this is doable, please let me know what it would cost. Mike
We're not equipped to do one-offs like that... it would be stupid expensive, e.g. a couple of thousand dollars. On our end all that really matters is the bolt pattern. I would do a simple cylinder and flange. The groove on the underside is to allow an O-ring to be inserted, just in case you get a light leak there. It's not essential. The front dovetail shape is only useful if you plan on attaching it that way. Since you're planning to use threads that isn't useful.
Thanks for the quick response, Doug. I kind of expected your answer, but I thought it was worth asking because I was assuming that if you make the camera faceplates on a CNC machine, an alternate version of the machine program could be set up fairly easily since the raw stock would be the same, and only a couple of dimensions are different. I agree that for the Stowaway adapter I do not really need the dovetail, but my thought was to keep the dovetail in the design because I have two other scopes which use the dovetail to attach them to the camera. Then I could just keep the modified version of the faceplate on the camera all the time to use the female threads for the Stowaway and the dovetail for my other scopes. Unfortunately, there is just not enough available backfocus with the Stowaway to be able to use the dovetail. I can do so when I am using a standard filter wheel cover, but not with the self-guided version. I really like the O-ring groove that you put on your faceplates. I think it is a great way to prevent light leaks. The other option I am looking for the Stowaway is just to use a threaded sleeve on the existing faceplate with 3.00-24 male threads and 2.74-24 female threads. Again. Precise Parts does not offer such an adapter because it does not fit into their menu driven design tool. It looks like I will have to try to find a local shop to do this. Mike
We use an outside supplier for CNC machining. We've weighed the pros and cons of bringing it in house. On the one hand it would be a bit less expensive especially on short runs. On the other hand we have an excellent relationship with our current provider, and their quality is very, very good.
