Tooooooo much travel

[Vistorx 0]

Hey, i want to print TPU 98A and i have some issue with retraction. But the retraction is not the reel problem.
The problem is simple, tooooooo much travel so too much retraction.

 

I can see the entire part form when i look only travel preview.

 

I looking for a way to optimise the travels without success.

 

Anyone have a magic parametring to avoid it?

 

You can find my actual 3MF project here:
V300_DUCT_03_3.3mf

 

Thanks all by advance for your help

Edited January 26 by Vistorx

[Slashee_the_Cow 410]

I'm not sure there's that much you can do about it - you just have a bunch of different feature types in non-contiguous locations.

Generally Cura prints support > walls > infill > skin, but if it considers it to have more than one feature, it'll do walls > infill > skin for one feature then walls > infill > skin for the next, and so on. Why does it do this? Consistent material flow. Support, walls and infill don't necessarily extrude at the same rate, so by grouping them, it can keep it flowing at that rate, before switching to the next rate for that feature.

 

But that model really isn't an outrageous number of travels.

You're definitely not the only who thinks how much there is in travel moves when you look on the surface is ridiculous for the result you get. But I'll explain them in your model (skip past the cow if you want to get to that part).

How much travel do you think my cute cow companion here takes?

If I go to preview without travels, seems not too complicated, right?

So how much travel is involved?

Holy cow! Especially when you look at all the non-retraction (dark blue) travels.

 

So why so many travel moves in yours?

I'll use layer 85 as an example:

Although if you want to skip past the step by step, I do offer some suggestions at the end, but I can't promise much.

This much travel is a fact of life.

 

Prints this little bit of support:

Travels to the next bit of support then does that:

Travels to the support in the middle and does that:

Makes a quick trip back to do a bit of support it couldn't do on the first run through:

Goes to the left and does the support there:

Travels to the bottom and does a lap around the perimeter:

Does a little trip inward and does the inner wall around this feature:

Does a quick move in without retraction and does the inside ring:

Moves to the main outer ring and does a lap of outside wall:

Does an arc travel around the inside inner wall for combing (not going through a wall):

Does a lap doing the outside wall on the inside of the circle:

A short move without retraction to where it'll start do it infill:

Draws as much contiguous infill as it can:

Travels to the next bit of infill and does a contiguous section:

Does an arc move around the circle anti-clockwise because due to combing, it won't take the direct route because that would pass through a wall.

Does as much contiguous infill as it can there:

Goes down to the bottom and does a circle of skin around the hole - I don't know why it doesn't comb:

Does a quick move outward and does the next lap of skin:

Moves without retraction and does the first line (which in this case is basically just a dot) of skin infill:

Moves without retraction and does the next line:

Moves without retraction and does the next line:

Okay let's skip to the end of that section:

Does a combing move (arcs around the inner wall until it has a direct path) to its next stop:

Does a lap of inner wall there:

Moves without retracting and does a lap of outer wall:

If you're wondering why it's done an outer wall between two inside walls, two reasons:

1. It's considered a different feature.

 

Travels without retraction and does the first lap of skin:

2. Skin (top/bottom layers) are treated the same as holes.

 

Does a quickie move without retraction to do the first dab of skin infill:

Fast forward to the end of that:

Does a combing move around the inside of the circle to get to its next point:

Does pretty much the same thing: inner wall > outer wall > skin:

and finally, does a direct move because there's no way it can comb this move to where it starts the next layer.

Okay, so while trying to demonstrate this, I couldn't get it to slice the same layer again the same way. To get the same way again I actually had to quit Cura and reload the project. My guess is because the model is broken (you should have gotten a warning about that when you imported it into Cura), but I'm not 100% on that one

 

So what can we do to to try and reduce the number of travel moves? Not a whole lot, really.

• Not really an answer, but... learn to live with them. They're because you have different feature types in several non-contiguous locations.
• Set Top/Bottom > Top/Bottom Pattern to Zig Zag. That way instead of travelling between each line it just draws a tiny horizontal line there.
• Use more walls: yes, I know, takes longer and uses more filament, but in this case it avoids having to do the two small bits of skin:
   
  It also allows it to make more direct moves because the distance is so short:
  
• Set Travel > Combing Mode to Not on Outer Surface. This will let it comb over top/bottom layers that aren't visible (i.e. not the bottom most ones for things visible on the bottom or the top most one for things visible on the top), taking shorter routes in certain cases.

 

Edited January 26 by Slashee_the_Cow

[Slashee_the_Cow 410]

I forgot the ridiculous solution to making sure there aren't many travel moves: make the damn thing solid.

Told you it was ridiculous.

 

Also looking at your print settings, I have no idea how the extruder on your printer behaves, but on my Ender-3 V3 SE I retract 2mm for TPU 95A (as opposed to 0.75mm for PLA).

 

If you're looking to avoid retractions but are willing to deal with the travel, here's the settings you want to look at:

• Travel > Retraction Minimum Travel: What it sounds like. Any moves shorter than this won't retract. Increase it and it will do more moves without retraction, however you risk dribbling in the model... that's what combing is for.
• Travel > Avoid Printed Parts When Travelling and Avoid Supports When Travelling: These increase the distance of travels, so you can get shorter travels (combined with the above setting) but you might drool on parts of the print that have already been done.
• Travel > Retract Before Outer Wall: Again, another "what it sounds like". The idea is that you won't carry a teeny blob from your last print move, because if you do carry it, it'll be visible where it starts printing that outside wall.
• Travel > Retract at Layer Change: That one goes without explanation.
• Travel > Max Comb Distance With No Retract: In theory, drooling while combing isn't a problem, so you can (in theory) increase this. In practice, if you don't retract for a long move, and drool during the move, the nozzle will be at a lower pressure when it gets to its destination, so you'll get underextrusion.
• Infill > Infill Pattern: Some patterns can be printed without any retractions, some with very few.
• Infill > Connect Infill Lines and Connect Infill Polygons (which ones appear depend on your infill pattern). Both of those will make it do any areas of infill it can as one continuous print move, saving travels, some of which might have retraction.
• Support > Support Pattern: Same idea as the infill pattern, except fewer patterns to choose from. Zig Zag is the best though.
• Top/Bottom > Top/Bottom Pattern: Zigzag can be printed in mostly continuous lines, only needing to travel to print bits it couldn't do on its first run (like bits around a corner or behind a wall or something).
• Top/Bottom > Connect Top/Bottom Polygons: Only appears if you have the Top/Bottom Pattern set to Concentric. But it will make it do its best to do the pattern in as long continuous lines as possible.

That's about all I can think of for now.

[Vistorx 0]

thank you for this responses @Slashee_the_Cow!
 

Now I've got lots of leads to explore to reduce the number of displacements and also to improve retraction.

If I can find something to feed the post with more convincing leads than others, I'll do it.

 

Thanks again for this super detailed answer.