With no real testing to actually see if it's true I SEEM to notice that there is a difference in surface finish (machine vibration) when using the feed rate override vs a programmed feed rate.

I'm doing some surfacing right now. 1/4" 2fl carb ballnose, 5000rpm and 15ipm, pretty fine step over (.010) and DOC. and I've been playing with some feedrates.

When I override the 15ipm feedrate to about 20ipm or so the machine has a more noticeable buzz (vibration) and the it shows in the finish.
If I program a 20ipm feedrate it seems smoother and leaves a slightly better finish.

I don't think this makes any sense what-so-ever from any program, mechanical or electrical standpoint and I've not really sat and compared apples and apples but that's what it seems like at first glance.
Anyone else notice?
M