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sinara-hw / meta

Meta-Project for Sinara: Wiki, inter-board design, incubator for new projects
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isolated SMA assembly #4

Closed jordens closed 4 years ago

jordens commented 6 years ago

Right now the angled SMAs get the metal teeth washer, then a plastic one, then the panel, then another plastic one and then the nut. AFAICT in many cases the metal+plastic washer stack on the inside of the panel is too thick resulting in a slightly angled panel and the remaining thread on the outside being too short. I'd either (a) drop the metal+plastic washer on the inside or (b) just use the plastic washer on the inside and ensure that the gap it fits in is not too large.

hartytp commented 5 years ago

@gkasprow has something been done about this? If so, please can you close this issue?

jordens commented 5 years ago

I don't think this has been touched. Which of the options has been implemented? And the bom should be updated to describe the correct stack.

gkasprow commented 5 years ago

We cannot do much towith BOM. The SMA connectors are often not available so we have to use similar ones. And they differ slightly in mechanical details. So we must make sure that additional washers between SMA and panels are installed to not bend the panel

hartytp commented 5 years ago

So, is "add suitable washers" something we need to add to the schematics annotations/assembly instructions? How do we ensure we don't have problems with this in the future?

gkasprow commented 5 years ago

Just make sure that quality control is performed correctly. And notify the board producer about the issue.

jordens commented 5 years ago

I don't have the hardware in front of me right now but I thing one issue was also that the washers collide with the PCB on urukul and are therefore angled. That will also bend the panel and might be something to fix in the layout. I'll check next time I have one on my hands.

jordens commented 5 years ago

And I don't think that having the board houses isolate themselves from these issues is a good solution. Similarly I don't like that they do their own unknown, secret, undocumented, and untracked testing instead of contributing to and using the a available test suites.

gkasprow commented 5 years ago

That's why we need to notify them each time the issue arrives.