I thought I'd share my experience with you folks to get some more opinions on this matter, and also to serve as a warning to potential buyers of this combination of filters and filter wheel.
I recently purchased a QHYCFW2-M-UltraSlim 36mm*7 filter wheel, and also a set of Astrodon E-Series Tru-Balance Series II LRGB 36mm filters. I was able to install 6 out of 7 of the filters no problem, but the Astrodon luminance filter was very slightly too large to fit into the filter wheel well. I measured the filter wheel using a digital caliper to be 36.11mm, and the luminance filter to be 36.15mm. I contacted Don at Astrodon to see what could be done regarding this issue. Don said that the filter wheel maker (QHY) did not follow the same tolerances they follow. Unfortunately Astrodon doesn't have any luminance filters that are smaller than 36.10mm and apparently I'm out of luck. His recommendation was that I find a local machinist to enlarge the well.
What irks me about this is that 6 out of 7 of my other filters fit no problem, and searching the web shows this isn't a common problem. There doesn't seem to be consensus as to who's tolerances (QHY's or Astrodon's) are the standard. I'm not pointing blame at either of these manufactures as I honestly don't know whether QHY's well of 36.11mm is unacceptably tight, or whether Astrodon's 36.15mm filter is unacceptably large. Either way, I feel helpless on what I can do here. Hiring a machinist to alter my wheel would probably cost the same as simply buying a new luminance filter.
Update: I want stress that Don's customer service in this matter has been top notch, replying to my questions via email very promptly. He mentioned that the next batch of filters will be machined to a slightly smaller diameter, and offered to replace my luminance filter once they are ready.
Edited by ArkabPriorSol, 01 December 2016 - 01:43 PM.