SWR Meter (10) - 3D printed project box design in Fusion 360

 I tried another SWR project box design using 3D printing rather than a sheet metal box.  The design philosophy is as follows: 

• Use flat panels as the box components, no U shapes or L shapes.
• Use 0.113" (3mm) panels
• Use countersunk #2-28 self tapping screws to assemble the panels together.
• Use enough screws spaced close together to ensure no open cracks along the seams where the panels join.
• All inside surfaces should be flat to facilitate laying copper or aluminum tape on the inside surfaces. 
• Copper tape on the inside surfaces should form a continous conductive surface inside the box to be RF tight.

The resulting box is show below, it is 3" wide, 1.5" high, and 5" deep.

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You can see the places where the #2 countersunk screws are used.   there are quite a few of them. 

The drawing below shows the box exploded into two sub assemblies of 3 components each.  

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After 3D printing the resulting box is shown in the photo below. 

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The box has a few problems: 

• There are a LOT of screws.  I only installed every other screw.
• The Torx drive on the #2 screws doesn't really drive the screws well. The driver slips out of the screw head often.
• Driving the self tapping screws into the edges of the 3 mm thick panels tends to cause the panel surface to dimple.

Even with problems above the box will probably be practically useful.   Next I will work to fit the SWR meter parts into the box. See the photo below.  I will need to add a couple of divider shields. From left to right, the SWR coupler will be installed on the back wall of the box. The logarithmic detector PCB will be mounted on the floor of the box, which the OLED display and the ATTiny85 controller will be mounted on the front of the box. 

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