Litho and Additional Moves

[bill565]

pcrv example Gcode.txt

Example GCode with photo carve settings

(1.98 KiB) Downloaded 236 times

original photo

Resulting Litho

Good Morning,

I have successfully cut a litho that I think turned out great for a photo of a photo on a cell phone.

During the cut, I noticed that I was getting additional travel on the x - y above the material for each line and direction being cut. This applies to all cuts. I think it is similar to the issue in the following post:

http://forum.vectric.com/viewtopic.php?f=7&t=6850

I think it might be in the pp and will check there as I go along, but thought I would see if there was any action on the post before I send in files to Vectric.

Anyway, I checked the g code and have isolated the additional movement code. I also checked that a second computer would produce the same results and that proved true. I changed depth and bit settings to see if there would be any change in the output but was not successful.

That said, I have attached the before and after as well as the settings and snippet of gcode so you can see what was going on. The additional travel lines are in each cut line regardless of direction so it multiplied the cut time by a factor of at least 3.

Any ideas? Thanks in advance.
Bill

[Dclifton2]

I just had the same problem, mine would shift to the right after every pass. It turned out to be a bad parallel cable. I found that when it was sent the first dir signal it missed and keep going in the wrong dir for a couple pulses.
Don Clifton

[tonydude919]

Bill,

Very nice litho you did. What bit did you use and settings? I've done at least 50 lithos so far and it still amazes me.

Tony

[bill565]

@dclifton2 - Mine is for sure a software related issue, as I found the "extra" moves in the code repeated in different computers with the same settings.

@Tony - The settings I used are captured in the text file attached. I still use the 30Deg v-bit with single pass, as I have had the best results with this method. I do agree that they are lots of fun and starting to get to a point where I can repeat results and quality.

Still curious to see if the additional moves can be answered like I have outlined in the text file attached and description. I have potential for more to be made but am worried about the additional moves and run time potential. I can edit the moves out now I know what to look for, but concern that they are there to begin with and repeatable is what I am hoping to resolve.

Thanks Bill

[BDM]

Did you try the solution offered in the reference link and set Z0 to the top of the material, just to see what happens?

[bill565]

Thanks BDM.

Yes I tried it and it does change the code. There is still an extra move, but it does remove the air cut.

I was hoping the answer to the additional code being added would have a way to avoid when referencing top of table versus the top of material.

In my mind, z to top of table takes care of the differences with the material thickness.

The referenced post also goes on to ask the question of why the difference with the additional code and that is what I was hoping to answer. I found that I can edit the additional lines out so I can work around it. It is more of the purist in me trying to isolate to something I am doing wrong, or is it something amiss in the software.

Bill