opulo-inc / feeder

Source for LumenPnP Feeders
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Circuit to 3D printed part clearances too low #24

Open Magpie-81 opened 1 year ago

Magpie-81 commented 1 year ago

Version Number

1.0.1

Bugfix or Enhancement

Enhancement

Description

Looking at the fit between the feeder mobo and the 3D printed body of the feeder, the spacing between pads/components and the printed parts seems too low. You have drawn some lines on the silkscreen layers, but still violated the outline. grafik Especially critical are the two big electrolytic capacitors, and the connector J3. For the capacitors, you have less than 0.5mm between the body and the 3D printed part. With some tolerance to the component placement and printing process, you risk to have a collision there. Another potential issue is the routing of the reset track on the top layer directly under the peeler motor. DC motors generate a lot of noise that can radiate easily, so keeping critical signals like a reset line (especially when it's not properly filtered by capacitors on the MCU) can cause potential problems.

Suggested Solution

Add a new layer to the KiCAD PCB for mechanical constraints that clearly indicate the usable space, and add notes like where motors or other parts of particular interest are. Leave enough free space for tolerances of component placement, solder blobs on pads and general 3D print errors. 1mm would probably be a safe distance when you add up all the worst cases. Be aware of radiated fields from the peeler motor sitting on top of the PCB and try to keep signals away from there, especially critical signals like reset lines or power tracks.