Feature request: Z reordering

[FeepingCreature 1]

I'm currently printing the part of a small table where I have to print the legs. In this phase, the printer does a lot of printing small parts, retracting, moving elsewhere, putting down a few lines, retracting, moving elsewhere, etc. This wastes time - pointlessly, since the distance between parts is large enough that the printer could easily build up a few layers in one go, before moving elsewhere.

 

Would it be possible to support this natively in Cura? Possibly with configurables such as "print head xy clearance" (minimum distance between parts to allow lower parts to be printed before upper ones) , and "print head z clearance" (maximum distance between lowest unprinted part and highest generated move).

 

I've made a small demo tool that reorders GCode files with this optimization. ( https://github.com/FeepingCreature/GCode-Z-Reorder ; you need to install a D compiler to build. ) Unfortunately, when I tested it, the print head started pancaking into already printed material. However, this may be a flaw with my printer - I suspect it slipped during extended Z down moves, a case that does not come up in regular prints. Please be cautious if you want to try it out.

 

Opinions?

Edited February 9 by FeepingCreature

[lance-greene 7]

cura already has this feature, you can put multiple parts on the buildplate and it will print 1 entirely before moving onto the next one, and completing that one before moving onto the next. you just need to list the size of your hotend in the machine definition so it knows how large it is so it doesnt hit anything.

[FeepingCreature 1]

That's not exactly the same.

 

What my program does is break up the object into nonoverlapping parts with a safe distance. Essentially, every disconnected part of every layer becomes its own "object". Then it tries to reorder the "objects" to minimize travel in three dimensions without the print head bumping into anything. Doing this manually in Cura would be impractical.

[lit-uriy 2]

12 hours ago, lance-greene said:

cura already has this feature, you can put multiple parts on the buildplate and it will print 1 entirely before moving onto the next one, and completing that one before moving onto the next. you just need to list the size of your hotend in the machine definition so it knows how large it is so it doesnt hit anything.

lance-greene, The idea is to not print the entire part at a time, and to print a few layers, then several layers of another part, then it repeats.
I also thought about this possibility. Then you can place the parts quite close to each other. And this will be less stringing.

[nallath 577]

I don't think the travel time in those cases will be that much. Getting this to work right is quite a hassle, so i doubt it's worth the effort at the moment.