Chris

I am not even a casual Blender user, let alone expert. Somebody else contributed the rendering. However, if it crashes, rather than giving an error message and it used to...

It is a known issue (with no simple fix) but at X_MAX, not X_MIN. You should always home X before Z and then it never happens.

Actually the start.gcode script provided homes Z first but the end.gcode leaves the extruder at the right, so the next start never crashes. The only way it could crash is...

The simple way to get round holes the right size is to use polyholes http://hydraraptor.blogspot.co.uk/2011/02/polyholes.html in the design so they don't shrink and so don't need material / layer height...

@mrvn, Yes it is. I have used it for 5 years with Skienforge and all my holes come out the right size. I compensate for plastic shrinkage due to thermal...

I get super high values indoors from stir fry cooking and making the bed. Near Manchester I get moderate values from traffic on the road outside. Outside in a shed...

Yes my values look right to me. I am showing how high it can be legitimately. What makes you think it is reading higher than it should be?

I don't think the effect of stir fry is steam because the sensor was in an upstairs bedroom not directly above the kitchen. All that would be noticeable in the...

I think you need the Pimoroni version of the BME library where BME280 is a class. On my system it is pimoroni_bme280-0.0.2-py3.7.egg

Perhaps you just need to uninstall the other version you had before. I don't know what search order it uses.