I have a converted G0704 mill.

I have a converted G0704 mill. I was trying to run some parts that were programmed with Fusion 360. on the first run I set my part zeros raise the bit
.200" and hit start. The bit goes straight down into the part several hundred thou. This only seems to happen on the first run after making changes to the program. The program will work ok after that.

Thanks Bruce

What changes do you make?

the only changes I made were to some other operations later in the program. I also used multiple passes on all operations because my mill is not stout enough.

I wanted to ask if machine 0 or part 0 was getting set, but, I’m starting to get in to deep water for my knowledge.

Edited: part was mistyped as pay

There are a few YouTube videos illustrating this with the tool running away on the z-axis into the workpiece. I can’t remember what the common cause was, if it was gcode, mach3 or electronics related? But I’m sure if you look up the mentioned videos you’ll find some indication of the problem in either the comments or video description.

I just did my first milling with Fusion 360 Gcode. When I hit start, the tool went to 0,0,0 and did a fast-move to the first operation, making a long scratch across my workpiece. Worked fine after that first move. I ended up manually editing one line of my GCode and no problems.
missing/deleted image from Google+


I finally made some good parts last night.

Yeah g53 just del that line as it depends on the work off set. I learnt that the hard way too. There’s an option to disable it in the post processor.