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Modified_Gemini

Excessive travel movements. (possible to avoid?)

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I've hit a little speed bump. My latest of designs, i noticed this happening much more as i started designing more case like objects. CRAZY excessive movements. 300mm of movement to travel around the object to print a dot, then travel back 300mm to print a dot, then back halfway to print a dot again? While i tend to have my settings dialed in pretty decent, that amount of movement is causing a loss of prime, and areas of the prints are really suffering. I just upgrades to 2.7 and still cannot find the proper combination of settings to avoid this. Or is it even possible?

Movements.thumb.png.46980f9e7784579f293000836bb86eb2.png

Movements.thumb.png.46980f9e7784579f293000836bb86eb2.png

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One reason is that the wall thickness is not even (the wall is wider in the corners because of the choosen radiuses). Another reason is that Cura tries to fill the remaining gaps as a separate step (instead of "en passant").

You can set "Shell" -> "Fill Gaps Between Walls" to "Nowhere". This will left small gaps between the lines in the corners, but that's probably not an issue in this case.

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Cool, that helped a little bit. Also shaved off 8 min print time. lol

Bit still scrolling through the layers you can still see a lot of movements.

I just tried removing the fillets, its pretty much the same luck.

I've tried clicking on the "avoid printed parts", but it still wont make a B-line to the next printing point, it would rather make 300 mm movements around the perimeter.

5a333f26f041e_Movements2.thumb.png.57db428897b4affb80c408728a74f685.png

5a333f2806e03_Movements2.thumb.png.02ddc63bc409d93969bf831c1ca2bf01.png

5a333f26f041e_Movements2.thumb.png.57db428897b4affb80c408728a74f685.png

5a333f2806e03_Movements2.thumb.png.02ddc63bc409d93969bf831c1ca2bf01.png

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If Cura would not be so obsessed to finish all lines of the same type (outer wall, inner wall, infill, in uninterrupted sequence, the major part of those excessive travel moves could be avoided. Advantages would be an improved printing time and a lower risk for a travel move to detach already printed lines. And of course one would get of the ugly combing lines which can atm only be done by adding retraction and z hop which needs additional time.

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I was directed to a setting, Travel -> Combine mode = OFF

It looks like it goes straight to the next print spot. Unfortunately movements seem far from optimized and still zig-zag across the print. But it may prove better, as 125 mm movements will probably be more forgiving in loss of prime vs 300 mm movements. It has also added a few more g to my print. (these are just visuals and have yet to print test)

Thanks smartavionics for offering to slice my model. I appreciate it, but it doesn't do me much good on my other models, as i only have Cura anyways.

5a333f2a71eed_Movements-Combine.thumb.png.3a90ff6912ba1ca0b6f35aeb33326ef1.png

5a333f2a71eed_Movements-Combine.thumb.png.3a90ff6912ba1ca0b6f35aeb33326ef1.png

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5a333f2a71eed_Movements-Combine.thumb.png.3a90ff6912ba1ca0b6f35aeb33326ef1.png

 

This one is a very good example for the unnecessary travel moves in Cura. IMHO there should be one travel move going to that circle and one leaving it again. Similar travel movements should occur for that infill in the front left corner. Second best way to do it would be to finish the inner walls except the innermost, then travel again to that spot, finish the innermost wall and right after it the infill. Best way to do it would be to print this area as a part of the second innermost wall line, printing something like as spiral for the remaining inner wall lines with the infill following before returning to the other inner wall path. Only very small travel moves would be necessary.

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For each part, Cura prints the walls and then the infill (there is an option to swap the order so it prints the infill first). The walls are printed grouped by level which means that within a part it can do quite a lot of travelling if there are many holes each with several walls. Doing it that way can involve lots of travelling but it does provide some guarantee of quality of finish as that is influenced by the order in which walls are printed. One of the challenges of creating the optimizer has been to reduce the travel moves while still observing the constraints regarding the order in which the walls should be printed in a particular region. The new optimization code groups the walls together so that it will try to print all of the walls around each hole together as a group so as to minimize travel. The optimizer only alters the printing order of the walls, it doesn't change the order in which the infill is processed. That remains a future task.

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I mostly understand the behaviour and the constraints. I was just hoping there was a simple setting i could flip to make it better. But i guess not.

But on the optimize code. Wouldnt it be pretty easy to just add a quick code that treats things seperated by a gap as its own item.

Like when you add a bunch of models on a plate it will print one at a time, so add a code tweak so where anything printed on a layer that is seperated by a gap is treated as its own item (even if it is physically the same model). It may not be perfect, but i think that alone would get rid of so many back and fourth movements.

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I mostly understand the behaviour and the constraints. I was just hoping there was a simple setting i could flip to make it better. But i guess not.

But on the optimize code. Wouldnt it be pretty easy to just add a quick code that treats things seperated by a gap as its own item.

Like when you add a bunch of models on a plate it will print one at a time, so add a code tweak so where anything printed on a layer that is seperated by a gap is treated as its own item (even if it is physically the same model).  It may not be perfect, but i think that alone would get rid of so many back and fourth movements.

Well, the're all simple settings to be flipped but, unfortunately, the setting you crave hasn't yet been created. However, what you mention later about treating items that have a gap between them as separate is indeed how Cura currently works. When I referred to a "part" above, what I mean is the Cura notion of a part which is basically an island of plastic separated from other islands by air. When you slice a model you get 1 or more parts depending on the shape of the model. If the model has bumps then at some point those bumps will get separated by air and they become individual "parts". Each part is printed completely separately to the others so all the walls and infill for that part will get printed before the printer moves on to the next part.

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Ooooh, you're right, doh! (And im not even drinking yet lol) because this is an electronics case, so much of it is on the same layer that connected, its bouncing around doing walls then infills then gap fills. So yeah, the setting im looking for is simply an optimize movements. So i cant wait for it to come out now!

I also did a visualization of single walls and 100% infill.. it did show much less un needed travels, but also added 3hrs to print time ????

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Here's a few seconds of video that shows an example of the optimizer's ordering of the walls. The part has 3 holes and is being printed with 3 walls. The walls start to be printed 5 seconds in.

Haha, I guess we would not realize if you would just show us a Simplify3D sliced object... ;)

Looking forward to that piece of code!

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On 9/14/2017 at 7:21 PM, smartavionics said:

Here's a few seconds of video that shows an example of the optimizer's ordering of the walls. The part has 3 holes and is being printed with 3 walls. The walls start to be printed 5 seconds in.

 

 

What are the relevant settings in Cura 3.2.1?

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Hello

yesterday I printed a quadcopter little frame and I observed still a lot of unnecessary (IMO) movements

I'm with CURA 3.3.1 on MacOS

Cura jumps a lot around to print walls and supports and I think infill too..

I ended up using again S3D because I think it has a better planning sequence.

 

Could you please list which parameters I must check in Cura to reduce travel movements?

 

Thanks

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I have looked at both of those files and they aren't really comparable as they have been obviously sliced with very different settings. You can see big variations in such areas as support style (zig-zag versus lines), number of lines in walls (1 v 2), amount of skin and so on. So, I'm not saying that the Cura output is great and the other not but I don't think they are very good examples to compare.

 

If you can provide me with the model (STL) I would like to slice it myself and see if there is any improvements that can easily be made.

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