Boxford TCL. Change from back to front tool post??

[John11668]

My TCL 125 has no turret .
I was having problems due to "saddle lift" in back tool mode when screwcutting with tool reversed. Reversing spindle and using tool right way up will only give me LH thread unless I cut toward Z+ (away from the chuck)

Now I have made alterations to overcome the saddle lift problem , but it seems to be I would be better doing turning in back tool mode (spindle c/w) , and threading in front tool mode (spindle cc/w)(unless of course I want LH thread)

I have seen this http://wiki.linuxcnc.org/cgi-bin/wiki.pl?BackToolLathe

What It seems to me that I need is the facility to change from back tool mode to front tool mode mid program.
Since Back tool mode is called up in the Ini file I cant see how best to achieve this.

Any suggestions folks ?

[magicniner]

That's a strange one, the system you use to create the program should automatically deal with your choice of tool orientation (front or back) and cutting direction (CW or CCW) in combination with the tool path type ( Int or Ext) and sort all that out.

[John11668]

Not using a "System" Magicniner
Knife and forking code as I go.

Next part of my exercise could be the cadcam system but not familiar with Cad yet.