Blade Server Rack

This page documents the original blade rack which has been replaced by a console holding one of the original blade servers.   A page showing the new console's construction is here.

We needed 2 servers with a backup to support Linux Castles hosting operation so here is what we came up with. 

Objectives:
	Inexpensive
	Easy access / repair.
	Higher density of servers.
	Very good cooling with no extra fans.
	Use easily obtainable materials.
	Rack may be used without an actual relay rack (just a pair of 2x4s).

Decisions:
	Take maximum advantage of ambient room air temp for cooling.
	Wooden rack consisting of two 3/4" peices of wood.
	Wooden (MDF) server backboard.
 	Most hardware from Home Depot or Lowe's.

Backboard:
	MDF (Medium Density Fibre) came in 48" x 24" sheets so it was easy to cut
	into 3 pieces of 16" x 24" sections.  If you cut the 48" diemension into
	three equal parts, it should yield three peces 16" (less 1/2 saw kerf)
	wide and trim to 21.5" high.  Chose bottom Angle brace as 12" x 16" to
	match server back board's shortest dimension.  I happened to have a 12.5"
	wide 3/4" plywood for base and 1" x 8" (7 1/2") for the top panel.  
	Design is such that two 1x8"s can be used for bottom panel.  Cut top and
	bottom panels to 20" long. 

Our prototype: 
	Shown in pictures, is a little taller than needed (we didn't want to get
	things too tight until we saw how it worked out).  A 12U module would be
	22.5" high.

Dimensions:
	17.75" inside clearance of rack.
	Base U dimension 1 7/8" high
		three holes .25" from each end and .625 to center hole.
		yielding 3 holes spaced from either edge of U: .25", .875", 1.5".
	Rack minimum space = 10 U.
	Since server backboard is .25" thick, decided to plough .375" wide grooves
	in top and bottom pannel for server backboards.  
	Grove in bottom is .25" deep, groove in top panel is .375" deep but server 
	board only takes .25" on top and bottom. Server backboard has .125" 
	clearance above and side to side.
	Outer sides (top of top and bottom of bottom) of rack panels should be an
	integral number of U high (in our case 12 U).
	Backboard size: X U x 1.75" - 1".  The number of U time U height minus 1".
Bottom panel


Top panel


Blade rear   Remember, I said it could be shorter.


Bottom rack panel ready to mount


Top rack panel ready to mount


Server Rack, with one blade but before the blade rack proper was installed.   Note one server still in a mini tower.


Blade side   You can see the standard mother board, mounted on standoffs, with a power supply, two hard drives, and a small control panel mounted to the 1/4" MDF blade board.   We built a small bracket (white here) to hold the top of cards plugged into the mother board.


Blade front edge, you can see the control panel here.   It has reset and power buttons, with leds for power and disk activity.


Blade PCI Detail-1   You can see an extra NIC and a video card (this is an older mother board without on-board video).


Blade Control Panel Rear Detail


More PCI detail.   You can see how the bracket is made from two Stanley 5" corner brackets and a short piece of 1/2" angle.   The angle brackets really are parallel, the perspective here is bad.


Blade rack after mounting with blade.


Side view of Blade in rack


Close up of top panel showing blade in grooves


Front of rack with blades 1 and 3 installed


Rack Rear view with 2 blades installed


Blade base board top rear with all components except the Pci support bracket.   The next PIC shows the bare board in the same position with mounting standoffs.   This is a better view of the control panel cable end plugged into the mother board header.


Blade base board top rear, bare.   The base board is made from 1/4" MDF board.   TeeNuts (6-32) are inserted from the bottom to hold the mother board standoffs and the control panel.   Two 10-32 teenuts are inserted from the top (right) to hold the 5" L bracket (Pci support) and three 6-32 teenuts are inserted on the left to old the power supply mounting angles.   Here, you can see the standoffs on top of the board already threadded into the 6-32 teenuts inserted from the bottom.   On each side, the rear, you can see the 6-32 clearance holes for mounting the hard drives.   The two teenuts at the far center edge are for mounting the control panel.
Blade base board from the bottom rear.   You can see the bottom of the 6-32 teenuts for the mother board standoffs and the two for the control panel at the top.   The tops of the two 10-32 teenuts Pci support can be seen on the left between tow of the 6-32 tee nuts.   The two sets of four holes near the top on either side of the control panel tee nuts are for mounting the hard drives.


Blade base board from top rear showing power supply and hard drives mounted.   You can also see the rear of the two power supply mounting brackets.  


Power supply mounting detail from the top.   You can see one of the mother board standoffs just to the right of the PS.


Power supply mounting detail from the bottom.