Hello again Tom......
I have tried it out, and it does return to the same speed......however, if I want to change to any other speed in the interim, I still need a way to accurately return to the same speed without relying on keeping the potentiometer unchanged. For those who do have a tachometer, this would be the advantage of having one. For those of us who don't have a tachometer, there needs to be a way to return to the same speed repeatedly, even though the speed has been changed for another purpose. This is the advantage of my simple method of having a pointer attached to the potentiometer with a magnet. It eliminates the need for a tachometer, and speed changes can be performed in-between the need to use a specific speed setting, and the need to return to that same speed setting.
Bottom line, Tom.....Keeping the potentiometer at a set exact speed won't work for my methods of lathe turning, but it might be satisfactory for other turners.
I also firmly believe that manually raising the speed is superior to allowing the electronics to do it. In my case, this may be an over-reliance on my need to be totally "hands on" with all aspects of turning, but you yourself have admitted that some out-of-balance situations may influence the absolute need to manually raise the speed. Also, there are times when I am adjusting the speed during turning, to eliminate minute levels of vibration change, which in some cases, does occur after removing wood from a spinning bowl. When this does effect the ability of lathe tools to perform the best possible cut, then manually adjusting the speed is essential for this purpose.
As always, I make no claims that my methods of turning are universally best for any other turners.....but, they have certainly evolved to a systematic method of achieving the results I demand of myself....and, of my finished bowls.
-----odie-----