This evening I replaced the KB Electronic speed controller on my 'new' (to me) Warco 7X12 Mini Lathe. I fitted a new USA made KB controller board that was provided with it by the seller. Out of interest I checked the temperature profile of the KB controller to see what got hot when the lathe was running. I could immediately see that a power resistor used to drop approx. 180VDC to 22VDC was running at 142 Degrees Celsius
It is designed to operate like that by KB and is deliberately fitted in PCB stand-off tubes to ensure air flow around it. I don't like to see those sorts of temperatures on a PCB though so I will be taking some action to correct matters and increase air flow within the controller housing. I also looked at the external gearbox, motor and head stock bearings to spot any unusual thermal activity. All was well in those areas.
The E4 made this such a simple and safe task and gave me immediate sight of a potential long term reliability issue. Highly recommended to anyone who needs a quick and easy view of temperature profiles at a safe working distance
UPDATE: Having slept on the matter, I am now convinced that my E4 has identified a previously undiscovered fault in my lathes speed controller. The resistor that is reaching 142 Degrees Celsius is not rated for such temperatures, so something is very wrong. Most likely an excessive current draw through it. But thats another story
The lesson here is how useful, and quick, the E4 was in visually identifying areas of thermal stress on the PCB. It has likely saved my new controller board from self destruction in the very near future.