G200 Index on the Fly causes the lathe to perform a move away, change tools, and move back to the part, to save time.
|The G200 does speed things up, but it also requires you to be more careful. Make sure you proof the program well, at 5% rapid, and be very cautious if you are starting from the middle of the program.|
Normally, your tool change line consists of a few lines of code, like:
Using G200, changes this code to:
If T101 just finished turning the O.D. of the part, you don't need to go back to a safe tool change position, when using a G200. Instead (as in the example) the moment the G200 line is called the turret:
Unclamps, in its current position.
Moves incrementally in the X and Z axes by the values stated in U and W (U.5 W.5)
Completes the tool change at this position.
Using the new tool and work offsets, it rapids to the XZ position called out on the G200 line (X8. Z2.).
This all happens very quickly, and nearly all at the same time, so try it out a few times, away from the chuck.
When the turret unclamps, it moves towards the spindle a tiny amount (perhaps .1-.2"), so you do not want the tool directly up against your jaws or collet when the G200 is commanded.
Because the U and W moves are incremental distances from where the tool is currently, if you hand jog away and start your program in a new position, the turret moves up and to the right of that new position. In other words, if you manually jogged back within .5" of your tailstock, and then commanded G200 T202 U.5 W1. X1. Z1., the turret would hit your tailstock - moving an incremental W1. (1" to right). For this reason, you may want to setup your Setting 93 and Setting 94, Tailstock Restricted Zone.
Information on this can be found at Tailstock Restricted Zone .