Cut order


#1

This is not a problem nor do I need support on this question, but I guess it’s more “Inquiring minds want to know.”

I am making pen boxes for my handcrafted pens and am utilizing living hinges. The design is working great and I have figured out how to do the engraving first, the inside cuts next and the final outline cuts last.

The hint I read about having the engraving run horizontally helped greatly.

My question has to do with the internal cuts - the living hinges mainly, although other cuts have the same quirks.

When cutting some of the parts, and the living hinges, all of which have the same color, GF will cut part of a hinge here, then part of another hinge next and then another part of another hinge and then go back to the first hinge and so forth. On the small parts it will make a cut on a section and then go do some other cut and then come back to that part later. I have made several of these boxes and the sequence seems to be the same every time. Every thing eventually gets cut but it looks like GF is making more work for itself than necessary.

Some of these individual cuts show up in the GFUI but all of the living hinge cuts show up in one GFUI cut panel.

I’m using Inkscape and I’m wondering if it has to do with the way I laid down the original cut lines in the design. I have combined paths and grouped items such as the lines for the living hinges.


#2

I would also love to know about this as I have the same problem on some of my cut files. Using Illustrator here.


#3

The motion planning is unknown to me, but with close-cropped cuts, you are dumping a lot of heat into the material, so spreading that out would be beneficial.

The token jobs that i did had the same repeating pattern too. That made me wonder if it was something in how the file was prepared.


#4

Ah Ha - so it’s a feature not a bug.


#5

Is it cutting part of a shape and then moving to another before coming back to finish, or are you saying that it is cutting shapes in random orders? If it’s a case of the first, then it’s because the lines/paths are not joined. I’ve noticed that in Illustrator, even when paths have been made compound, that sometimes the underlying paths are not actually joined; making a compound path does not automatically join the underlying paths. I have no idea what the equivalent is in Inkscape though.


#6

I have no idea, just a guess. What jbpa says makes sense, except all of the token instances were copies, so it should have behaved the same for all of them. And spreading them out to reduce the heat doesn’t hold either because in cutting them out it would do row upon row continuously, skipping four here and three over there out of 50 and return to finish those.


#7

I am 100% (but not authoritatively) convinced this is part of the motion planning. Any job with multiple close cuts (dupes or not) have been spaced out. YMMV of course.


#8

It also avoids over-burned corners IIRC. I don’t think that’s the reason it does the dance it does. Someone else had posted a suggestion to create paths in an order that would avoid the legs of an acute triangle from being cut in a continuous fashion.


#9

I have started to plan out my paths to avoid corners and acute angles being cut in one pass and it definitely results in cleaner corners and cuts, though I have to touch up inside corners with a file sometimes to get a close fit joint.
I use Solidworks and it seems that the GF follows the order of the lines being drawn about 80% of the time, so I use this to do my cut order, as well as making several colors to do different groups of cuts. I also use this to prevent movement of the parts due to being separated from the sheet. I plan out the last set of small cuts to separate all the parts from the sheet.


#10

Since this isn’t a problems & support topic, I’m moving it to Everything Else where the conversation can continue.


#11

…and I don’t know how the motion planner works so I’m not much help. :slight_smile:

I do know that the print time difference between GF currently-optimized (or not) and fully-optimized for speed prints is small - usually single digit percent. The motions between cuts and engraves are fast relative to the cuts and engraves themselves.