Too many long travels with unclear purpose

[sofos_d 1]

I sliced my model with Cura 4.13.0, and it got many long travels.

 

What is the purpose of those travels?

How could I get rid of them?

I attached the project containing small part of the model, which nevertheless illustrate the phenomenon.

test.3mf

[nallath 1,124]

Those look to be combing moves. The purpose of those is to not leave the object since the nozzle can start to ooze at that point.

[sofos_d 1]

It looks like I found out what is going on, but have no idea what to do with it.

 

The hotend draws infill lines on the left:

 

but after each one line it travels all the way to the right:

 

and then returns back to draw the next one:

 

So, is it possible to configure Cure so that the hotend would just draw infill lines one by one without those long travels?

 

[gr5 2,210]

I disabled combing (set it to "off") and that eliminated those long travel moves and it also cut your print time from 3:40 to 2:15.  So it saves about 1.5 hours.

 

However you may get more bumps or strings on the outside of your part (you'll have to try it and see).

 

 

[sofos_d 1]

Thank you for the hint about combing. That Combing Mode feature is a tricky thing. And I would rather reduce the number of artifacts on the outer surface. So my choice for combing is 'Not on Outer Surface' - the movements of the hotend are more reasonable compared to 'Not in Skin' (but still not absolutely clear), practically no travels across outer surface, and print time is 2:31 (for test model).

[GregValiant 1,330]

Have you considered printing it with all Walls (set the Wall Count to 5 or 6)?  That would avoid all those little back and forth movements that the skin causes.  It gets the print time down to about 1:45 as well.

[sofos_d 1]

Yes, but it will be winded and unwinded back similar to watch spring. Not too strong, but many-many times. And I am afraid 'all walls' style will result in stress concentration along the boundaries of those 'walls' and the fatigue failure is more likely than in case of classic infill with crossing lines pattern.

[GregValiant 1,330]

"...but many-many times."

I think it will be all about the material.  If you pick the wrong one then "many-many" will become "just a few".

Good Luck!!

[gr5 2,210]

Did you try a print to see how bad the stringing is?  Maybe there won't be any stringing.

 

Also, maybe you don't need any infill?  Or if you only want the infill to support the top layers then you can do variable infill.

[sofos_d 1]

I know my printer 😉 It does stringing sometime, so if I can prevent it, I will. Especially with this model, which longer than 1 meter being unwinded mechanical clean-up would be exhausting.

 

And I need infill, because the printed object should be tough and durable.

 

Anyway, thank you vary much for the suggestions and the discussion 🙂