ROACH_Motel - david-macmahon/wiki_convert_test GitHub Wiki

The ROACH Motel is a 1.3U enclosure, with mounting holes for an ATX size PCB, the Sunpower PSU, dual ADCs and cutouts for the ROACH rear panel. Provision is made for custom front faces, including holes for LEDs and ADCs. The Enclosure is designed to be compatible with a 19" computer rack when fitted with Intel's AXXBASICRAIL kit.

The box is "RFI aware" (meaning that it was designed with RFI considerations), but it is not RFI tight. It offers ~60dB of shielding? (requires verification), with most of the leakage coming from the power cable and peripheral leads (eg. ethernet jack). Seams are welded shut and removable panels have overlapping edges.

Provision is made for a Mini-Circuits type two-way splitter to be mounted internally (for feeding clocks to the ADCs) and there is sufficient space for additional RF components, should these be necessary in your application (see pictures below).

You might want to consider adding a heatsink to your PPC to aid cooling.

Design Philosophy

DESIGN: The ROACH enclosure was designed to be manufactured using a single sheet of aluminium to achieve a high level of RFI shielding. The design allows for all seams to be welded with no riveting required for separate panels. Each wall of the box has a double fold, that is an L-bend off the base and an L-bend into the top surface for the LID. A further step on the top surface creates a recess for the LID. A gasket can be fitted to this recess to improve the overall shielding of the enclosure. The rear edge of the LID is formed into a L-bend which again provides improved shielding. All VENT holes have been carefully designed to keep the Shielding Effectiveness as high as possible.

MATERIAL: Aluminium was chosen for two reasons, firstly due to it's light weight and secondly with corrosion in mind. The enclosure should not be susceptible to corrosion while retaining it's conductive properties. Aluminium can be coated to prevent corrosion and still retain it's electrical conductivity through a chemical Kenverting process. Basically, the lighter the colour the better the conductivity.

Thermal Simulations

The cooling solution for ROACH 1 hardware was designed using CFdesign by Blue Ridge Numerics.

Production Prototype Manufacturing Files

Media:K8000_0030V3.zip‎‎, Version 3 is the first release of the manufacturing files.

Media:K8000-0030v4.zip‎, Version 4 includes the following changes:

Serial port mounting hole diameter increased, Exhaust Vent holes shifted, FAN securing hardware modified, Extra RAIL mounting holes added, EARTHing screw hole added to rear panel.

Media:K8000_0030V5.zip‎, Current Release (11 March 2011)

Labeling and Manufacture Drawings

Media:K8000_0030V5.pdf Insert and Standoff locations

Media:K8000_0030V4_backpanel.pdf Backpanel Engraving/Labeling

Media:ska_1-3u_frontface.pdf Custom Front Face,

The manufacturing file for this front face is found in the above ZIP file "K8000_0030V5.zip". Specify to the manufacturer which of the RF input holes are to be used or omitted. See the Frontface_F.pdf and Frontface_X.pdf below.

Media:Frontface_F.pdf SKA's Custom F-Engine Front Face

Media:Frontface_X.pdf SKA's Custom X-Engine Front Face

Media: front face pics

Media:Lid securing extrusion.jpg Closeup detail of the Lid Securing Extrusion

Media:Backpanel engraving.jpg Closeup detail of SKA's Backpanel Engraving

Roach Enclosure Hardware List (BOM)

Media:Roach_LRU_BOM.xls

The BOM file lists all the designed in parts and extras used in the Roach Motel by the South African team.

LED Status PCB

The LED status PCB interfaces to the front panel of the Roach Motel and displays ROACH status, driven by GPIO.

HINT: An assembly JIG will have to be constructed to ensure the correct height of the 3mm LED's when soldering. The LED board and ROACH enclosure are designed in such a way that the LED's just slightly protrude through the enclosure front panel.

Circuit and GERBER files

Media:K3000-0176_B.pdf PDF of Schematics

Media:K3000-0176.zip Gerber files

Media:Assembly Drawings_Designator.pdf, Media:Assembly Drawings_Comment.pdf Assembly Drawings

Media:K3000-0176_top.JPG, Media:K3000-0176_bottom.JPG Altium 3D Images

Media:Status LED pcb.jpg Photo of PCB.