Creating System Layouts
This tutorial will give you some idea on sizing of rack units (RU) and best way to apply to 2d layouts
Step 1: Rack Unit Sizing
For systems layout design you need a general awareness of space, especially of your 19" rack, and rack mount equipment. You need to know how RU height, equipment depth, knowing this will determine type of rack and how much space you need. Note, when planning a system build is also good to factor in extra space, whether its for ventilation, cabling, or extra equipment.
Here is a snippet courtesy of wikipedia:-
A rack unit (abbreviated U or RU) is a unit of measure defined as 44.50 millimetres (1.752 in). It is most frequently used as a measurement of the overall height of 19-inch and 23-inch rack frames, as well as the height of equipment that mounts in these frames, whereby the height of the frame or equipment is expressed as multiples of rack units. For example, a typical full-size rack cage is 42U high, while equipment is typically 1U, 2U, 3U, or 4U high.
Please note that the official width of a 19 inch rack is 482.6mm,
All of our models are round up to 485mm width,
The reasoning of this, in some situations, it is for easier for grab, and snap, to the corner of a 2d block when working purely in a 2d systems layout. (In reality, there would be a small gap of at least a few mm either side)
Please see image of a basic example below:- (notice no gaps in these racks)