SPINDLE SPEED AVERAGING
Mach3 can keep a running average of the last 8 revolutions. At the start of any pass it either uses the
average OR the last measured time. Every thread starts with an unloaded spindle, the 8 rev average is
typically unloaded average. ( unless your turning very slowly on the spindle and very unlikely it's less
than 8 turns in the air prior to a thread pass)
So the correction code is all that controls speed during the cut to take into account the spindle slowdown
caused by hitting a hard spot or an average slowdown due to harder material.
The averaging is discounted for correction, it cares only about the real last index to index time,
and it compares that to the locked in average or locked in last rev just prior to the thread pass starting.
Rule of thumb is 3 to 5 diameters times total thread depth for unloaded spindle travel of the Z axis.
I use and would recommend you use spindle speed averaging. It helps if there is a "out of rage / fluke / high" rpm
included in the averaging. You then get a more refined feedrate. One "fluke" may not influence as much as you
would think.
Some of my words but mostly Art's,
![Wink ;)](https://www.machsupport.com/forum/Smileys/default/wink.gif)
RICH