I am a new Mach 3 user, setting it up on a new machine I have just finished building. I have been a long time user of a CNC Shark and the Vectric software, both VCarve and Aspire latest versions.
I have set-up Mach 3 for my machine after watching all the videos and reading the pdf manuals. Everything seems to work ok - steps calibrated, etc., however, I use no homing or limits switches.
BUT I do have a problem. I have a test piece (very simple Aspire file) and I put the piece in the middle of the table, center the bit in the middle and zero to the top of the piece, zero everything after loading .txt file, etc.  When I turn on the router and cycle start the first thing the router does is go straight down 3/4" (the thickness of the work piece) and then come back up and tries to cut the image.
I've searched forums, read manuals, reviewed set-up, etc and nothing. The piece cuts ok on the Shark CNC.
I've attached the dxf file and the gcode.  Hopefully someone can help - I greatly appreciate the assistance.

Thanks,
Don

Have you got the Z direction correct? Going up the Z DRO should increase and going down it should decrease.
Have you got a safe Z set up? If so what have you got it set to?
If you attach your xml it will possibly help finding the issue.

Hood

Hood

Thanks for the response.  Z direction is correct. Safe Z, if I think I'm right, comes with the individual project file designed in Vectric Aspire and is set as 0.2 and the home position is set at x 0.0 y 0.0 z0.8.

I've attached the xml file.

Thanks,
Don

I am a new bee and probably know less then you do, but trying to learn. so was looking at your problem.
I took your .XML file and loaded it in my Mach3 program it seem to run the simulation OK. Playing around one time it seem to start -.8 then I remember to Zero the machine Coord's, then Zero the work Coord's that seem to fix that. I am not running a machine jst the program looking at the problem.
I also looked up all the G code That at the front of the code.
Here a list of what is there.
G00 Rapid Move
G20 Sel inches
G17 sel XY Plane
G90 Absolute
G40 cutter Comp
G49 Tool lenght
G80  Cancel Canned Cycles
G70 Inches
G91.1 Incremental
G00 Rapid Move
G43  Z0.8000H1  Tool length offsets
G94 Units per Minute
Seem like some may not be necessary.
I hope you post the solution when you find it.

Don, every thing seems to run fine here with your xml .
Do you have any height offsets set up for the tools in the tool table?
Hood

Thanks for the replies.

Today I went and air cut the program a number of times and it finally struck me that the Vector Aspire cut file was running in reverse - it would first plunge down the 0.8 safe z then back up and try to move the 0.2 rapid z gap and then raise up to cut material.

After I figured it was running in reverse, I went to the Config/homing/limits section and reversed the Z setting.

Everything worked fine, except the Z axis hot keys of page up and page down are now backwards and it doesn't seem like they can be changed.

With Z reversed the  little test program cuts correct except the Z hot keys. The Y and X axes cut correctly and their hot keys are ok.

How can I fix this?

Thanks for your patience and assistance,
Don

I do not see any work offset in you program.

Do you zero your part with G54?

Try putting a G54 at the beginning of your code.


Jeff

You can reverse the jog keys from Config menu then System HotKeys.
Just click Z++ and a box will pop up asking you to press the key you wish, press the PgUp and that will set that, then move to the Z-- and do the same.
Hood

Thanks for all the prompt assistance.

After I changed(reversed) the Z setting in the config/homing/limits section and then reversed the Z hot keys everything works great. Test piece cut ran perfect.

Don't understand why I had to reverse the Z setting, however, if it works I'm not going to question.

Thanks for everyone's assistance
Don