Good info, all around, John. Advice from an experienced person is usually the best kind.
Regarding the standards changing .... that's an odd one! One would think there'd be a "MkII" or something ... y'know ... at least SOME kind of ~noises~ made about the dimensional changes within the catalog.
I wasn't aware that Moon used a module mounting hole that is something other than 0.170" (spec per a CAD drawing that Roger Arrick drew up in 1999 and has since published on the Synthesizers.Com website).
This may be helpful, here's my own observations of some dimensions (with the exception of the Dot Com module mounting hole, source credited above):
0.170" = Synthesizers.Com module mounting screw hole ID.
0.235" = Head OD of M3mm stainless steel Phillip's head screw.
0.270" = OD of M3mm nylon flat washer.
0.260" = Head OD of #6 black oxide wood screw (Dot Com systems).
0.265" = Head OD of 6-32 stainless steel Phillip's head screw.
0.310" = OD of #6 nylon flat washer.
MakerBeam is pushin' these really cool (ugly?) looking ~square~ headed allen screws for their assemblies. They look pretty neat ... well ... within their own universe so to speak. I don't know how they'd look among a crowd of synth modules, but all on their own and used in a context where ~skwair hedz iz kewl~ they look very unique (as in *good*).
I wonder if using screws other than what MakerBeams offers would be a better choice? Between Bolt Depot, Fastener Express, and several other vendors there's certainly plenty of sources available for M3mm screws.
There's also MICRORAX ... another make of construction rails that (of course) uses their own designs of nuts and rails. Rail seems to be right in there when it comes to cost per foot. Screw and nut designs .... well, we're back to M3mm stuff again. But the nuts are a two-hole "nut plate" that slides into the railing. Screws seem to be nuttin' special, just plain old M3mm socket head (aka "Allen screw") ... so we're right back to 0.235" head OD (or there abouts).
MICRORAX (nuts and bolts and stuffage) link =
http://www.microrax.com/Hardware-c6/
MICRORAX (rails baby!) link =
http://www.microrax.com/Profiles-Beams-Rail-c3/
Both MakerBeam and MicroRax use a 10mm x 10mm beam (aka ... "profile" or "rail" or "beam" .... geez people, pick one already!). So when it comes to working out rail placement you're working with the same centers, regardless of manufacturer.
BTW, MICRORAX is a "Maydin Murica" product, right up in the Pacific Northwest, the parent company is "Twintec" owned and operated by a pair of identical twin brothers. So at least you're not dealing with exchange rates and international shipping and so on.
MICRORAX rails are not end-drilled (there's no hole down the center), so mounting their rails into a cabinet may require some other piece of their hardware to accomplish the task.
There's also "8020" rails, but those are large and costly. I remember seeing a complete Synthesizers.Com system made entirely of 8020 rail ... the whole damned thing (built by Dot Com as a special order for someone with a lot of money and fame). I recall Roger commenting on the high cost of using 8020 railing.
In summary, I don't know if any of this stuff is going to change the way MU/5U/MOTM systems are designed, constructed, or offered ... but it is nice to know that what I initially thought was a pipe dream is actually a reality. It's use can certainly make the DIYer's life a bit simpler, especially if mixing formats is in the design sheets.
Thanks for all of your help, John.
This concludes my morning bla bla bla ...
Brian ... (that other Brian).
