Tool path starting point

[RamCastle]

Okay folks, Newb here but need some help.

Machine will not start cutting at the indicated start point shown on the toolpath preview.
I have created a very simple text, V Carve tool path to use as a test / sample job.

I have set the home on the machine with acorn.
I have set home for the part.
The toolpath is using the center of X and the center of Y for the part and then is supposed to send the machine to the cutting start point which would keep the text job in the center of the part. But it goes to a location just left of center and then runs the cutting off the right side of the part.

I tried twice including going back to the V-Carve file and making sure that it still showed the center of X and the Center of Y for the file home and it did.
This is on a converted PM-728VT

Any help would be appreciated.

Yes, I tried a search, it's difficult to describe a search for this situation.

Thanks, Rick

[ShawnM]

You have to set work coordinate zero (as you call it "home for the part") in the exact same spot that you have the XY datum position set in Vcarve. If you have the XY datum in Vcarve set in the center of your design then you need to set your part zero in the same place on the material. Make sure you are not using an offset.

[Nigelo]

When you have set your WCS as Shawn has described above, load the job and Graph it instead of running it. This will quickly show if your toolpath is correct in relation to X and Y but if not, where your error is.

[suntravel]

Without the g-code file it is difficult to help you...

Uwe

[Ken Rychlik]

The first thing that would help is if you watch all of the vectric free tutorials. Then making sure you set up the machine to match the way the design file is set up is the only other issue.

[ShawnM]

When you have set your WCS as Shawn has described above, load the job and Graph it instead of running it. This will quickly show if your toolpath is correct in relation to X and Y but if not, where your error is.

This is probably the best advice you can get. ALWAYS, ALWAYS, ALWAYS press F8 to GRAPH your job BEFORE you hit cycle start. This will save you not only money but headaches. There's nothing worse than ruining a $300 piece of carbon fiber plate because you skipped graphing the job to check for errors. It also offers many other crucial checks to be sure you are setup correctly and not machining outside the machine's work envelope and it allows you to SEE exactly what is going to happen BEFORE you press cycle start.

Thanks for pointing that out Nigel, it's second nature for me but I see many people not graphing jobs before they start.

Please take some time to read and understand machine zero and work coordinate zero and how they are setup in CNC12 and your preferred CAD/CAM software. Vcarve is simple to setup your work XY datum but you also need to set that same work coordinate zero in CNC12. Then it'll start cutting at the correct point.

[RamCastle]

Thank you all for the help.
I have been reading and watching videos but as you all know, it's not the same until you get your hands dirty.

I finally got it to run correctly today and learned a valuable lesson from you all regarding the graphing. Very good advise, thank you.

Although I can't come up with a good reason why it shouldn't work, it appears that I was setting the Z reference the same as the part top and it didn't like that.

Thanks again!!
Rick

[ShawnM]

You can set Z0 to the top of your material or the top of your spoilboard. It works either way but you have to set it the same in both Vcarve as well as the machine when you setup your WCS zero references for x, y and z axis.

[Houseman303]

Z0 to the top of your material. always! every negative z value means that you are machining the workpiece. This means you can always leave the Z safety height at the same value. If you take Z zero at the bottom, you have to recalculate the safety height every time and that's where most mistakes happen.

[RamCastle]

I'm not talking about Z0 for the top of the the workpiece, I'm talking about "Z Reference" and setting it with a probe to calculate tool offsets. For some reason this was keeping it from running correctly as it's the only thing I changed and then it ran correctly. Of course I could have missed something else all the other times I tried running but I don't think I did.

Of course now another issue, my Z axis ball screw bearing/nut keeps coming loose causing the head to works it's way lower and separate the coupler.