One thing I haven’t found mentioned anywhere is the spacing between mounting holes. I think I read that the holes are sized for M3 screws, but I didn’t see the distance between them given.
If you’re screwing them into a wood strip it doesn’t matter so much, but there are some advantages to a Eurorack-style rail system; easier to rearrange and you don’t get sawdust everywhere. But for that you need a consistent hole spacing.
Edit to add: Is there such a thing as threaded inserts with metric spacing? Obviously 1HP spacing (5.08 mm) is problematic for Kosmo. At best you’d have gaps between modules. But as far as I know all threaded inserts are HP based. So if you wanted to use rails, you’d probably be forced into sliding nuts.
Yeah, sliding nuts is the way to go if you want rails for Kosmo. Or manufacture your own with 5mm spacing (since you might have 25mm modules according to Sam’s spec, 1cm apart wouldn’t work).
Incidentally, I just ordered some threaded wood insert nuts in order to try and make some wood rails that are a little more durable with module repositioning:
EDIT: On the other hand, you can get to some pretty small gaps with standard HP spacing:
Oh hey, I just noticed this link on this page. It’s truncated vertically but you can tell where the bottom holes are, and if I assume the black rectangle is supposed to be 200 mm square, then the mounting hole centers are on the corners of a 192 mm square, that is, the centers are 4 mm from the edges.
Also, if the black circles are meant to be the mounting holes, then they look to be about 2.5 mm diameter or so, therefore sized for M2.5 and not M3 screws.
They appear to line up exactly with the Eurorack spec from the top. 3.2mm hole, center 3mm down. I didn’t measure with sub-mm precision, but an M3 bolt has some play. They appear to only be 3mm from the side to center of the hole as well.
New plan, and this time it’s tested! I bought some of these:
They’re meant to melt into plastic, but intended uses never stopped me before. I drilled 5/32” holes and squeezed them in with a dab of glue for good meassure:
