In the file I just uploaded of the cabinet sides, I mentioned the
replacement of the sheet metal boxes with the vector rails did
NOT considerably change the overall wieght. This is an out an
out lie! A typo. It should have read is NOW considerably lighter -
basically about 30 pounds lighter.

These rails (called struts) have slots along both ends and on
one side for inserting their special square 4-40 nuts where ever
you wish. These slots run down the full length of the strut, so
you can slide the nuts down the whole thing. These three slots
offer billions of different mounting options for both modules and
the struts themselves. Because this system doesn't use the full
threaded inserts that Doepfer. A. Sys and A. Sol uses, you can
position the nuts where ever you need them down the strut -
which comes in handy when mounting A. Sys next to Doepfer as
you don't have that *really* wasteful gap in between.

You cannot use standard nuts - these are square, not hex
shaped. kind of a drag, but the nuts are pretty cheap.

Details:

Mouser part info dor the rails - $10 for 30 inches:

http://www.mouser.com/index.cfm handler=displayproduct&lstdi
spproductid=632959&e_categoryid=68&e_pcodeid=57403

Vector p/n: TS300

they also have other widths availalble, one is cut perfectly for
RACK MOUNTING SYSTEMS - same width as the Doepfer rails:

Mouser link - $7 for 16.85 inches:

http://www.mouser.com/index.cfm handler=displayproduct&lstdi
spproductid=201024&e_categoryid=68&e_pcodeid=57403

Vector p/n TS169

Mouser link for the square 4-40 nuts - $5 for 25:

http://www.mouser.com/index.cfm &handler=data.listcategory&
D=*NT47PA*&terms=NT4-7PA&Ntt=*NT47PA*&Dk=1&Ns=SFiel
d&N=0&crc=true

Vector p/n: NT4-7PA

Vector does not sell direct. without huge quantities involved
WIsh they did, they are about 1/2 mile from my house.

hope this helps,

- P