There are a few known issues in this design: - the barrels in the bottom half only attach to the battery bay but not to the bottom face. This is not completely wrong (i.e., with stiff enough plastic and a good 3D printer, this ought to work), but might be inconvenient to manufacture.
- the "funnel" of the USB receptacle is about 1.6 mm from the outside wall, but the standard only gives us 1.3 mm to work with. According to the Micro USB 1.01 specification, the main body of the receptacle should protrude 0.7 mm over the PCB edge, plus 0.3 mm for the "funnel" (both in figure 4-11 on page 24). Then there is a clearance of at least 1.3 mm between funnel and the overmold of the plug (figure 4.9, page 22). That's a total allowance of 2.3 mm between PCB edge and outside wall, while we have 2.2 mm. So making this fit nominally may just be a question of moving the USB receptacle closer to the PCB's edge. In real life, we'd want a bit more mechanical tolerance, too, I'd say at least 0.4 mm. - there are no cut-outs for USB and the switch yet. - for the switch, I should also design the user-visible knob that moves it. I'm having second thoughts about horizontal placement of the screws. Now that I know that relatively short threads are available, it may be better to design with that in mind, and make the screws perpendicular to the bottom face. Near the battery, we have about 7 mm between the outer surface of the bottom half and the bottom side of the PCB. A 5.0 mm screw (thread length) should therefore fit nicely. A vertical arrangement would allow moving the screws closer to the battery, since the bulky thickening around the head would slide under the curvature of the battery cover. The screws could also be offset by a few mm from the side, thus making room for components. - Werner _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
