STV CNC Plasma Table - nest shift?

[Pyro1983]

I attempted cutting my first nest today. The first several designs went great. Then when cutting the perimeter of another one in the nest, it's almost like something shifted, lost position etc.. It cut off the sheet into an area that was already cut out (and thankfully removed) , torched went down and got a z axis limit switch error. Just like to get some idea on what could have happened , what to check etc.. thanks in advance. I have a short video but can't post it. Not sure if the picture will be much help. I posted a private video on my YouTube channel, this link SHOULD take you there. Let me know if it doesn't work.

[adbuch]

You may have picked up a stray node left over from a previous drawing that got included in your cut paths. Perhaps post your actual file - the complete file with all the nests included. What program are you using to do your drawings? I seem to remember Inkscape, but too lazy right now to go back and review all your previous posts.

David

[Pyro1983]

My drawings were all purchased in a large package. In the package was each image in SVG,DXF, and even some JPGs. The DXF files had been giving me issues. I use myplasm which only opens DXF's. So I of course started out loading the DXF files and when I did the myplasm sofware showed several incomplete paths/cuts. So I went to inkscape, loaded the SVG's and then saved as DXF files. When I loaded them into myplasm, everything looked good. I DID come to find that the eagle image it messed up on had a huge number of nodes. I thought I had checked the images I selected but apparently missed one. I'll add the nested file which was done with myplasm , and the file I saved as a DXF to add to the nest. I'm kind of anxious to get back to the shop and figure out whats going on, but it's Christmas Eve, and its literally 2 degrees out right now

I cant even attach the nested file. The extension is MYP2...

[acourtjester]

I opened you file in SheetCam and it is very large, in the screenshot the red square is 4'X4'. I would be very hard to see any small problem with that size, I assume you needed to reduce it for your project. I played with the SheetCam screen zooming in and out I cannot see anything that is not normal except for the size. Not knowing how you restarted the cut to give an idea of why it was then out of place. If you always start in the same place and zero out the DROs before running the cut file it should be the same. I would do a test movement without the plasma on to allow you to see it things will happen as the should. The table should do all movements in a non-plasma operation for you to watch.
I would be very careful using files from an unknown source, run test movements on the G-codes will same you metal and heartache. You will see member post files with the note "I have not cut this yet" so you know to test run it before using metal. As you have seen things can be hidden from view and cause problems. CNC will follow exactly what the G-code tell is to do, but it cannot see "booby traps" or mechanical errors.
Will Myplasm open or run other G-code you have if so I would look at buying SheetCam to do your planning.

[adbuch]

Now I remember - we looked at another of your purchased files a while back with the same problems - many short discrete unconnected path segments. I expect that you have perhaps opened multiple files into your software, or not completely deleted the remnants of a previous file before opening a new one - and your program has picked these up while creating the cut paths for your current file.

David

[adbuch]

I see no extraneous nodes outside the outer perimeter of the eagle, so this most likely confirms that you had remnants from a previous file present when you attempted to create your cut paths.
David

[Pyro1983]

How do I go about making sure there's no remnants left?? Shouldn't opening a new file be just that? New and empty?

[adbuch]

What program are you opening the new file with? And what files are you "nesting"? Having nested files suggests more than one file open at the same time with the increased likelihood of one file picking up stray or remnant nodes from another. What program are you using to do your "nesting"?
David

[Pyro1983]

What program are you opening the new file with?
David

All I have is inkscape(which is what I was using to convert files to dxf) the myplasm software of course and fusion 360 when I need to design something other than "art" . Is there something better I should look into that will easily work with myplasm?

[adbuch]

And what files are you "nesting"? Having nested files suggests more than one file open at the same time with the increased likelihood of one file picking up stray or remnant nodes from another. What program are you using to do your "nesting"?

In other words - what is your specific work flow?
David

[Pyro1983]

And what files are you "nesting"? Having nested files suggests more than one file open at the same time with the increased likelihood of one file picking up stray or remnant nodes from another. What program are you using to do your "nesting"?

In other words - what is your specific work flow?
David

Ok so here goes.. like I said previously, I had issues using dxf files from the package I had purchased. The svg files looked decent. Since myplasm will not open svg's, I created a folder on my desktop first. Then, using inkscape, I opened each svg that I wished to nest and saved as a DXF to the folder. Once I had all the files I wished to nest, I opened myplasm and used that as my nesting software. That's pretty much it I believe.

[adbuch]

Perhaps there is bit of confusion about the term "nest" as you are using it. Are you manually nesting multiple files into a single file? Or simply opening each file, one at a time, using Inkscape and then saving each individual file in dxf format? If you are converting these from svg to dxf one at a time, then I would suggest you use a new instance of Inkscape for each file conversion. That way, there should not be any remnants from a previous file getting mixed up with a new file conversion.

If you are indeed opening multiple svg files into the same Inkscape window, and then converting them all at once into a dxf file containing multiple individual drawing files (what could be termed "nesting") then I would recommend that you stop doing that and only convert a single file at a time.

Perhaps post the dxf of one of your nested files so we can have a look.

David

[Pyro1983]

I did convert the files one at a time. I did not close inkscape each time. As I converted them, I saved each one as a dxf to a separate folder so I knew which ones were converted and usable. Once I had them all in one folder, I opened myplasm which allows for nesting multiple files onto one large sheet. Does that make sense?

[Pyro1983]

Theres a picture of the nested stuff. I can't attach the actual file because it won't let me post a .myp2 file created by myplasm

[acourtjester]

Something I have done with Inkscape is have a few sessions of inkscape opened at one time. You can separately open many sessions of inkscape at one time and switch between them easily using the copy and paste function. You can use this as a way to nest (move around however you need to) the different files in one of the sessions as you final combining of the files to move into Myplasm to create your finished plan. The aspect ratio (sizing) stays the same when you go from one session to another, no problem moving one file to the combination, their original sizes with stay set when going to a large group.

[adbuch]

OK - I understand. I would perhaps try closing Inkscape after each conversion so that there is no possibility of picking up stray nodes from one file as you convert another one.

David