changing axis direction in post

Hi, I am trying to modify a generic fanuc 5x post to work for a thermwood model 70 with 9100 controller. I need to change the direction of some of the axis, ie. z+ needs to be z- etc. My first thought was to change the wcs, tool plane and construction plane, either I get a rotating motion thats not possible or I get the same direction. Then I went into the machine def manager, and looked for a way to change it there, that didn't work.
So does anyone know a way to reverse the sign on an axis in the post? Or another way besides manually find and replace to signs?
thanks

Any suggestions on how this could be accomplished? Maybe there is something I missed in mastercam? How would you do this. Does everyone program 5 axis parts with wcs set to top?


Also, I see some settings in the post referring to machine matrix. The reference doc doesn't say much about this or top mapping. Any thoughts?

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Originally Posted by thermgood

So does anyone know a way to reverse the sign on an axis in the post? Or another way besides manually find and replace to signs?

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There is a way, but .....

Are you sure that the machine is configured that way ?
or is it the way it has been programmed ?
or is your interpetation of the movement in error ?

Most machines have the Z along the spindle axis with Z+ going back up the spindle away from the table. So you must get the machine axes down pat 1st before thinking it's mastercam's machine definition that is at fault
IMO, Z+ going towards the table is a big crash in the making.

MDI the machine to go G0Z5. , now MDI in G0Z10.
the spindle should move away from the table

Progamming is always assumed that the tool is doing the moving,
even if the table moves to the right, the tool is travelling in the X- direction, or has to be commanded to go in the X-

Let us know if this misunderstanding is your problem, then we'll go to the next step in programming.

It's an old machine, the way it's setup is without any offsets. Machine 0. It doesn't have any offset tables. It could be changed to run in the normal direction, but the owner doesn't want to do that. There are years worth of programs written manually that run on this machine.
The z and y are in the opposite directions than normal. It's a vertical machine c,a on the head x,y,z on the gantry, table is stationary.
z- is up away from table, y- is moving toward the back of the machine, x+ is moving to the right. If I rotate the wcs 180 degrees about the x, things in mastercam point the right way.

For anyone thats interested, I found my answer in the Mastercam help file. There is a post in there that is well commented, and is set up to allow axis flipping. Basically it is to multiply the axis by -1.

ex.
xabs = xabs * -1

Where can I find this help file, I am in a similar position.