Right Side Spindle Lathe

I've got an old TBI lathe that I've retrofit to use LinuxCNC and it's fantastic. I ripped everything out except the ways and the spindle. Now I've put it back together with: new spindle motor, new servos, new servo drivers, MESA 7i92 and 7i76 breakout, custom stuff for the turret tool-changer and much more. My only problem is that I'm having trouble getting everything to square away from a directions point of view.

The display on LinuxCNC assumes the spindle is on the left (when viewed from the operator's POV), but my spindle in on the right. Also, I cut on the far side of the part, not the near side. Basically I can't get the couple things to line up that I would like, namely: positive z away from spindle, positive x yielding larger radius part, keyboard arrows causing carriage to move in approximately the direction of the keys, direction of carriage movement matches that shown on screen (naturally because my lathe is a 180 degree rotation of the what is assumed). I can get most things to make sense by rotating my keyboard 180 degrees so that up is down left is right etc, but it can still be confusing when looking at the screen.

To be clear, I've already set the scale values for my X and Z output axes so that x+ is away from centerline and Z+ is away from spindle, and the display shows this. However, when I press the left arrow things go right, and when I press the right things go left. Maybe the simplest step is to re-map the arrow keys for inside linuxcnc.

Does anyone have an idea as to how to rotate the display axes 180 degrees (not with GEOMETRY: -X-Z, but actually rotate the display so that the spindle is on the right?)

I've heard I can modify the axis.py code, but honest to GOD, I can't find the axis.py file in my system. Any help would be appreciated.

Here are a bunch of pictures/videos of the project for anyone that's intersted:
goo.gl/photos/NEwdRg1oR9mfZdzk8


Thanks in advance for the help
-Marc

Awesome. Thanks for the tips. I was able to do one thing that proved pretty useful, and that was to remap, only for the purpose of jogging the arrow keys. It turns out it was very simple once I found the linuxcnc (axis.py) code thanks to BigJohnT.

There is a function, or called bind_axis(dir, dir, axis), and if you invert the order in which "Up", "Down" appear, or the order in which "Left, "Right" appear you effectively invert the key, but without affecting the sign of the movement on the axis. You could even modify these if you wanted to switch your left right to be up/down because your machine is at 90 degrees to your computer.

Thanks for the hot tip BigJohnT
-Marc