1u rack fan shelf

1U rack “shelf” for mounting PC fans for rack cooling. Put one at the bottom of the rack (intake) and one to the top (exhaust).

Adjustable rack depth (depending on metal rod length). Works with a variety of fans - fits 80mm/120mm/140mm PC fans. Optionally supports a fan controller PCB and I/O modules (display, buttons…).

Reference build

• rack dimensions 42U, 60cm x 80cm
• 4x 140mm PWM fans
• desired extra modules: fan controller + 0.96 LCD screen on front panel

You can skip the fan controller and LCD screen, replace these with 1uw-blank panels.

Print these parts

• ear-left x 2
• ear-right x 2
• horizontal-clamp x 6
• fan-mount-clip-double x 4
• fan-mount-clip-single x 8
• 2uw-fancontroller x 1
• 1uw-blank x 5
• 1uw-096-lcd x 1 + 1uw-096-mounting-clip
• handhold x 2

Additional hardware needed

• 12mm aluminum rod, cut to 53cm length x 2
• 8mm aluminum rod, cut to 36cm length x 3
• threaded inserts, ID M3, OD M5 x 60
• rack cage nuts + bolts x 8
• 140mm PWM 12V PC fan x 4 + mouning (ie rubber shockmount legs)
• M3 x 8 bolts x 24
• M3 x 10 bolts x 36
• 12V power supply, 5.5mm x 2.1/2.5mm barrel jack, 5A
• ESP fan control board
• 0.96 I2C display
• 4-core connector wire, ~60cm

Assembly

1. Print all parts
2. Assemble the front and back “panels”
   1. Insert threaded inserts into all modular frontpanel pieces (2 per piece); and bolt them together
   2. Insert threaded inserts into handhold pieces (optional), and bolt them together
   3. Add M3 bolts to the “ear” pieces (12mm rod holders), screw them in loosely
3. Insert threaded inserts into all rod holding parts (horizontal-clamp, ear-left, ear-right, fan-mount-clip-single, fan-mount-clip-double)
4. Assemble 3x fan bearing 8mm rods
   1. Slide 4x fan-mount-clip-* parts onto the 8mm rod. Two rods get the “single” versions, one rod (the middle one) will get the “double” versions
   2. Add 2x horizontal-clamp parts to the ends of the 8mm rods
   3. Add M3 bolts to the threaded inserts (screw them in, loosely)
5. Add 2x 12mm rods to the ear pieces of the front panel. Support this half-assembled piece, panel-down on a worktable. You will be holding an open “U” shape. Tighten the 12mm rod holding bolts in the “ear” pieces
6. Slide 3x assembled 8mm fan-bearing rods onto the 12mm rods, from the top of the open “U” shape
7. Slide the assembled back panel to the top of the 12mm rods. Tighten 12mm rod mounting bolts
8. Place the assembly horizontally on the work table. Space the 8mm fan bearing rods by eye for your fans
9. Place only fans onto the fan-mount-clip parts, and mount them securely in place (depends on your fan mounting method, I used pushpins into rubber shockmount holders)
10. Review final positioning, and tighten all mounting bolts
11. Mount the fan controller board and LCD screen (optional)

Mounting into the rack is preferably a two person job. You can either:

• tilt the whole assembled piece to get it past the front and back rack rails (12mm rod holding bolts need to be loose to allow for couple of cm of flex/movement)
• or you can take off the back panel entirely, insert the assembly from the front, then re-attach the back panel

If the rack “depth” is wrong and can't be adjusted using the 12mm rod mounting bolts/flex, review the length  of your 12mm rods - you need either shorter or longer rods.

Notes

The front/back panels are compatible with Modular Frontpanel (1U 19' rack system) UW blocks (enables to add custom modules to front/back panel, ie a 0'96 status display).

Fan controller: I used this ESP fan controller board by ESP32 and more. It allows to control up to 4 PWM fans, and has support for temperature sensors, power conversions and GPIO headers. The design files include an optional 2UW mounting plate (2u-fancontroller) for this controller board.

Vibration - you might want or need to add some kind of rubber shock absorbers between your fans and the fan mounting clips. I used “SILENT WINGS PRO 4 140mm PWM” fans, which are premium quality and already come with rubber shock absorbers and suitable pin mounting.