[destroyer125]

Hello,

I have been playing around with my CNC Taig mill for some time now running the Mach3 Controller. I have experimented with several cam programs over the last couple months and I seem to be having the same problem with all of them. Its such a simple problem, but can be amazingly time consuming to fix. I have used full licensed versions of Bobcad 18 and Bobcad 23 along with Lazycam, Cambam, and various other freebies. I am running BobCad 23 Mill now.

I am able to generate great 2d and 3d Tool paths with these programs but every single program always generates the path backwards on the Z axis. It starts at z0, then as it is susposed to be stepping down, the path generated always goes up, and the rapid plane always goes down and slams into the part, snapping my tool or fubaring my part. The programs do not allow me to put negative coordinates in for rapid planes and all. If I go in and change all signs on all z coodinates around manually, the program runs fine and I get the part I wanted to make. Experiementing with 20k Lines of code for a complex 3d part; changing each Z in notepad isn't an option.

Thanks

[MrWild]

It sounds like you have your Mach settings wrong. Sometimes the setting can be wrong in the CAM program, but if all the CAM programs are doing the same Z moves, it is in your mach or EMC2 settings. It is probably as simple as selecting to invert the Z direction pulse.

When I turned my router around so the cable carrier was to the back, inverting my X sends the table moving in the right (X+) direction for it's new orientation. Sometimes the biggest problems have very simple solutions.

[mcphill]

When you push the manual move Z+ in Mach3, does the spindle move up or down? If it moves down, you need to reverse your direction in MACH (or reverse the wiring on the stepper motor) - problem solved. If not, we need to dig in further.

Let us know what happens to go to the next step.

You are right you can't use a negative rapid plan - that would (in a normal situation) drag the tool through the floor as it moves around - the CAM program won't let you screw that up! It's not the CAM program's fault, though - you need to set your machine up to the environment it expects (Z+ is up, Z- is down).

[CNCRim]

Hello,

I am able to generate great 2d and 3d Tool paths with these programs but every single program always generates the path backwards on the Z axis. It starts at z0, then as it is susposed to be stepping down, the path generated always goes up, and the rapid plane always goes down and slams into the part, snapping my tool or fubaring my part. The programs do not allow me to put negative coordinates in for rapid planes and all. If I go in and change all signs on all z coodinates around manually, the program runs fine and I get the part I wanted to make. Experiementing with 20k Lines of code for a complex 3d part; changing each Z in notepad isn't an option.

Thanks

Just want to clear it up Z+ the machine going down? and Z- machine going up?

[destroyer125]

On my machine, + goes down, - goes up. Pressing Page Up for Jog goes Down, Pressing Page Down for Jog goes Up.

I am guessing the wiring on the plug for my steppers are backwards on the Z axis? I bought them pre-wired.

[MrWild]

PSSSssssst READ POST #2

[ger21]

Most people use Z- going down, and Z+ going up. That's what all the CAM programs are giving you, but you set up Mach3 the other way. You can reverse the Z axis in the Homing Limits screen by checking the reverse box.

Page Up should move up, Page Down should move down.

[destroyer125]

Problem fixed! All 3 Axes were moving backwards. Simple reverse of all of them in Mach and the mill is running as it should now.

So, I went out and botched a part, Hoorah!

[DeadTom]

Problem fixed! All 3 Axes were moving backwards. Simple reverse of all of them in Mach and the mill is running as it should now.

So, I went out and botched a part, Hoorah!

Been there and done that, welcome brother....
Good to hear you firgured it out with the help here on the Zone.
DT