Im I something wrong? it looks like when I change front/rear tool post something wrong is going on with the offset
when I set tools from front post only - working
when I set tools from rear post only - working
BUT when I change front and rear post - something terribly wrong happened

the only way I found to change front and rear is to change first to a tool with zero offset from front post, then to a tool with zero offset from rear post, and then I can use tools from rear post, then to go back to front post I have to change tools with zero offset in opposite way
why is that ?!?

You must keep the tools set as either front or rear, you can not have a combination of both I am afraid. It is one of the many things that are wrong in turn and according to Brian not possible to fix in Mach3 but should be addressed in Mach4.
Hood

too bad....
it looks like the way I explained (not sure if anybody can understand me) it is changing properly, not sure yet, but I wasted too much time to find out what is going on
but if still not working properly then I cant use mach3 for my lathe too.... I have tolls on front and rear
anyway, just wondered if Im doing something wrong or this is another bug
thanks for your reply

I think Homing also works but I prefer not to do things like that.
I had a front turret and also a rear turret. As my rear turret was default then I just used Rear tools in the  tool table and set the offsets up accordingly. Worked ok but you just had to use negative values for X when using tools in the front. In code that did not have negative X values I inserted a G51X-2 before a front tool and G50 to cancel, was a pain but it did work until you forgot to cancel before a tool change
 I then got Dolphin CADCAM and made a custom PP for it, the X values were correct for any code it produced.

As for not being aboe to use Mach, well I think EMC is similar in that respect or at least it was what I was told when I enquired regarding front/rear tools, I was told just programme neg x values where appropriate. As that was the same as Mach there was no benefit to change.
Hood

the G code will be relatively simple, few tools used but few seconds each, so Im not going to use any CAM software, I will write my own G code, I tried EMC on my mill, much better, may be I have to try it for the lathe too, but very busy now, may be another day

G51 is also idea, but I didnt write any G code in the last 15 years and it is still hard to make it work with all tool offsets and orientations and front , rear, and few bugs messing around just to make it more difficult

If hand coding then easy enough to do with any method, whether that be your call a dummy tool or homing or setting all up as front or rear exclusively and coding for +ve and -Ve X values as needed or even using the G51.


Hood