Hi, I am new to the forum. I have a DIY CNC Dave Gatton Sidewinder. I have a question , I am using Fusion 360 for my design software and Mach3 for the CNC. When I run the simulation in Fusion 360 every thing seems ok. When I take the G-code to mach3 and run the program, my Z is backwards. it goes down when it should go up. Any help would be appreciated.

Hi,
conventional direction is downwards Z decreases.

At Z=5, say, the Z axis is 5 units above the surface of the material. If the Gcode calls for Z=-0.1, its intent is to cut 0.1 units off the top surface.

Does your Z axis DRO decrease as you lower the spindle? If not you need to change the Z axis direction. Config/Ports and Pins/Motor Outputs check (uncheck)
<Dir Active Low>.

Craig