Raspberry Pi Bramble Rack Support and Connect

Design of a Raspberry Pi cluster required a rack or support. Taking the initial concept from thing:30563, the support uses the RCA Video and Audio plugs to hold the circuit board on edge.
This support has the following advantages.
1) The hole for the audio connector is sloted, so that manufacturing variations for the distance between the RCA Video and Audio are not a problem.
2) Air gaps in the support can allow for more passive air flow around the circuit board.
The other changes were to the distance between the mounting holes to fit a Rack Mounted Canterlever tray that can be purchased from RS. The supports can be connected together using the BrambleConnect part. Alternatively attach to an enclosure using 4mm bolts.