[Noteworthy] E-stop

Good points and it brings to mind one of the problems with the commonly seen "drum switches" which, when grabbed for in a panic, could easily be swung past the center off position and the motor would still be running, usually in the same direction.
Mark S.
 
I haven't given up on seeking out further information on E-stops and how to apply them to my CNC mill. I've got a thread going on the Precision-Mathews forum and in the interest of keeping my build thread consolidated in one place I'll continue asking questions over there. Here's the link if you are interested. http://www.hobby-machinist.com/threads/taking-the-cnc-plunge.24858/

Tom S.
 
An e-stop should remove power from all electrical and mechanical devices, however for the sake of safety a machine may have a motor that needs to also be stopped as soon as the e-stop is pressed and quickly as possible. A free running motor taking excessive time to stop such as a high speed spindle motor on a CNC machine can be dangerous if not stopped as quickly as reasonably possible. A delayed rely using the regenerative power left over from the spindle controller or some other dynamic braking system is needed in these cases when an e-stop button is pressed. It is also a legal requirement to do so.
 
An e-stop should remove power from all electrical and mechanical devices, ........ It is also a legal requirement to do so.

For the most part that is correct. What can you do without some Government regulation telling you how to do it.

Removing all power is not always the case. Take a system with hydraulics and removal of Power will shut down the pump and then a heavy "thingy" will drop on something that will be bad.

Each machine and system needs it's own safety evaluation about E-Stops, LOTO, Operation, PPE, etc.

Remember to document all of your reviews and efforts. This will be handy if you get a government official at your door to help you.
 
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