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nk25719 / PMD___aka-KiCad-esp32-6leds-2switches-1pj-circuit-

In this repo I am practicing KICAD. Created an ESP32 DevKit V1 module and a PCB footprint. I designed a circuit around this ESP32 consisting of six lamps, four switches, and two power jacks and added a voltage regulater to Vin to maintain a supply of +5V. (This project was originally made of two switches and 1 power jack and was named homeWork2.)
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Retain the PCBA assemblies of 202407 in Rev1 enclosure and check the how #34

Open nk25719 opened 1 month ago

nk25719 commented 1 month ago

Is your feature request related to a problem? Please describe. A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] We do not know what screw is going to mount the PCBA into the enclosure

Describe the solution you'd like A clear and concise description of what you want to happen. We need the exact manufacturer's name and part number and the distrebuter name and the distrebuter part number. the diameter holes of the four corners are 3.5 mm

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered. Design our own screws. or Use glue or Use tape

Additional context Add any other context or screenshots about the feature request here.

samoyin commented 1 month ago

I found a screw with a 3.5mm diameter hole. Here are the Specs. It's a M3.5-0.60 Phillips Pan Head Machine Specs: DIN 7985A / ISO 7045. The distributors are Frontec screws. Other information can be found here. ([https://monsterbolts.com/products/mach-phil-pan-blk-m3-5?variant=21508467523667])

ForrestErickson commented 1 month ago

@samoyin

Regarding, "I found a screw with a 3.5mm diameter hole." A 3.5mm screw into a 3.5mm hole is not guaranteed to have clearance. May have negative or interference clearance.

For example. The PCB material is drilled to 3.5 mm nominally. It may be under sized. Then the PCB has copper plated on to the hole. It is now defiantly smaller still. Even if the screw exactly fits through the hole, on one of the four holes there are four total and the thermal expansion and humidity expansion of the PCB and the enclosure may not be the same and so all four holes and screws may be able to fit at one combination of temperature and humidity but not others.

It is also difficult for an operator to place screws through a hole with zero clearance.

There is a vocabular about fit. See this document for some insight on clearance for holes: https://fpg.phys.virginia.edu/fpgweb/useful_info/Clearance_Hole_Drill_Sizes.pdf

Similar but for metric screws https://amesweb.info/Screws/Metric-Clearance-Hole-Chart.aspx

With experience you want to learn how to never specify unnecessarily tight fit or unnecessary precision.