Odd behavior on a router table.

[Spectric]

Hi I was rebating some sapele boards on my router table and suddenly noticed that the cutter was behaving in a strange manner, almost like it had come loose. Checked it was tight and all was ok, so restarted and the cutter instead of being just a blur was or looked like it was changing speed to the point it was more defined than a spining cutter should be. Initially thought "could it be the Triton router" but the speed could be changed as normal and it had not lost any power, still working as normal. Then getting more curious I looked at it from another direction and it was fine, just a blur so was it some odd blip. No it looked wrong from the other direction still and then I realised that it looked ok because I had been blocking my magnetic LED light source. The issue is my LED light, it has a strobe effect on my router when it is not at full speed, I was running a slightly reduced speed because of the 2.5 inch rebate cutter I was using. It does not make the cutter appear stationary at any point so not a safety issue but just looks wrong and makes you think something is wrong until you find the cause.

 

[spb]

Be a bit careful with 'not a safety issue' - at the right (or wrong, depending how you look at it) speeds, there's every chance it will appear stationary.

 

[Cabinetman]

My workshop lighting is old-fashioned fluorescent tubes, and when I was designing the layout I had the opportunity to put half of them on one phase and half on another as I am fortunate to have three phase electricity, I had heard about blades appearing to be stationary, never seen it, but I’m glad I separated them out.

 

[Argus]

In my distant electrical past I seem to recall regulations concerning discharge lighting - fluorescent in those days - that produce a synchronous frequency effect that makes some rotating machinery appear to be stationary.
I believe that single fluoro lamps were prohibited. Lighting was done with twin fittings to cancel the synchronous effect.
As spb said, be careful. It can be dangerous.