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tonycstech

Cura slicer questio.

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Every model i print has common problem.

Imagine something as simple as a box with holes in it for screws.

1.2mm wall thickness with 0.4mm nozzle makes it 3 lines of extruded material.

So you have the perimeter for the box its self printed by 3 lines of extruded material.

Then you have perimeter for each hole that are 3 circles of extruded material.

Problem is that slicer does not complete outer nor inner perimeter before it moves to another.

For example: It would run 1 line of extruded material for the box outside wall and then one circle of extruded material for each hole and repeat the process 2 more times.

It creater a problem. Nozzle gets wiped when it travels and holes end up being dry or not properly attached causing them to peal off when nozzle hits it the next run.

There are 2 ways it can be fixed.

#1 retract before printing another perimeter (would be most effective)

#2 complete 1 perimeter at the time instead of 1 run per perimeter until they all done.

 

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Ok plugin has a problem.

Layer numbering is all screwed up

Layer #1 in the plugin is actually layer 2 in the viewport. I had this problem when i was developing my Gcode layer modifier program i posted here somewhere. http://umforum.ultimaker.com/index.php?/topic/4185-tweak-at-layer-number-windows-application/

As for disabling combing:

Its enabled by default because its good. If i disable it, i will get so much retraction that print time will increase and i will run into problem of getting filament grinded to a point where it will start to slip. I use it for small objects only.

Slicer still needs change.

Why not just complete one perimeter at the time ? It will save travel time and get rid of problems like "dry start next perimeter"

By default it should complete the perimeter completely before switching to another perimeter (if any) and retract before each perimeter start (no need to retract before infill, its unseen)

 

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Ok plugin has a problem.

Layer numbering is all screwed up

Layer #1 in the plugin is actually layer 2 in the viewport. I had this problem when i was developing my Gcode layer modifier program i posted here somewhere. http://umforum.ultimaker.com/index.php?/topic/4185-tweak-at-layer-number-windows-application/

 

The RetractWhileCombing plugin uses the same layer numbering as it is used in the gcode (or it uses the layer height which is non-ambiguous).

It's true it's not the same layer numbering as in the Cura GUI but that's rather an issue of the GUI and not something which is screwed up in the plugin.

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As Cura plugins are post-processors and affect the written gcode they should speak the same language as the gcode IMHO.

However, you're right pointing out that the situation of having different numberings in the GUI and in the gcode is not ideal. Maybe Daid could take equal numbering into consideration for Cura pink unicorn?

 

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OOh OOh cant wait ! :shock:

I wonder if stepper controls will be available without having to start printing.

Need to do things without having to print anything, like leveling and measuring max print area

Is there a link for the development page or "post your requests" king a thing ?

Thanks for good news !

 

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Slicer still needs change.

Why not just complete one perimeter at the time ? It will save travel time and get rid of problems like "dry start next perimeter"

By default it should complete the perimeter completely before switching to another perimeter (if any) and retract before each perimeter start (no need to retract before infill, its unseen)

 

While I see what you mean. There is a difficult case here. There is a chance (pretty good one actually) that the 2nd or 3th lines of the inner&outer perimeters meet up and form a single line. In which case a single 2nd or 3th line has multiple outer lines.

 

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Is it difficult to make the code generate in a way that it would complete entire thickness of the wall before switching to printing another wall ?

I am no gcode programmer nor cura developer so i wont know.

I am not sure what you mean by (outer and inner perimeters meet up)

Does my illustration matches to what you mean by meet up ?

New Bitmap Image

 

When 2 perimeters get close, filling can take place instead, just like in the case of printing pyramid where inner edges get sorta like filled rather then printed as perimeter so that shifted layer will have base to print on.

 

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Your illustration has the inner circle colors the wrong way around. But what I mean is when the circle it closer to the edge, then the brown line will become 1 line for both the inner hole and the outer line.

(Also, engine wise, the information about which line belongs to which hole/outside is not kept with the lines)

 

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What do you mean by wrong colors ? Thats how it prints for me. Starts with inner perimeter outside then goes to inner perimeter inside.

Then repeats same thing until all 3 perimeters are completed (1.2mm with 0.4mm nozzle makes up for 3 perimeter runs)

When it jumps from one to another, it starts dry.

Drives me nuts that it doesnt complete the entire perimeter before starting another one.

 

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What do you mean by wrong colors ? Thats how it prints for me. Starts with inner perimeter outside then goes to inner perimeter inside.

 

No it doesn't, it prints the inner hole the other way around.

 

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Cura calls them insets. And prints them from the inner inset to the outer inset. The outer inset is the outside of the 3D model. The outer skin so to say. The outer-skin of the circle-hole is the inner most circle. As that's the part you visually see.

 

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Ok

After days of testing and learning what change retractwhilecombing does i learned that its absolutely useless in my case.

I have a box with 3 holes in it. There is not always combing from getting to one hole to another, mostly motion is straight to from one perimeter to another, so plugin wont make it retract while combing.

In order to retract from one perimeter to another, i have to disable combing.

Biggest problem is 1st layer. I dont want to print raft to help it stick, but if it retracts each perimeter then it sticks PERFECT and doesnt look like it getting dragged and pealed off because of combing.

Is there a plugin that would retract only # of layers and then do combing ?

Is there a plugin that would retract before each perimeter every run ?

Say perimeter is 3 runs thick. Because CURA does not complete each perimeter but jumps from one to another, it would be nice to always retract before each switch. It will prevent allot of problems in my opinion :)

Please advice me with the solution.

THanks !

 

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RetractWhileCombing should do this job if correct settings are applied. Please be aware that there is a minimum travel length specified with the plugin. If the travel distance without retraction (this is how the plugin understands 'combing': simply a travel without retraction) is smaller than this minimum lenght, no retraction is applied.

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Is there a way to make it retract every time it prints another or part of another perimeter ?

I need it to retract every time it travels to another perimeter, so it wont pull filament out of the nozzle on its way there.

Thanks !

I love CURA and i go allover telling people to use it and nothing else, but this one thing bugs me. Need to retract each perimeter even when combing is enabled or not, its a quality requirement and a prevention step that seems obvious to me.

If posting video here would be eazy, i would demonstrate the problem i suffer every time i print something that would make nozzle travel from perimeter A to perimeter B and not retract causing it to peal and every problem that follows when your thing dont stick.

 

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Doesnt matter. I need it to retract every time perimeter switches.

There is a bigger problem. CURA does not finish 1 perimeter, it shifts between perimeters until they all as thick as user specified.

Say i have a box and 2 holes inside. It will jump from outer wall of the box to inner holes back and forth until they are as thick as i need. In my opinion its a waste of travel and print time.

 

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RetractPerimeter

There :) I hope this explains.

Perimeters can be in different locations thus have different distance. Tweaking the distance is not the solution, it should retract no matter how far or how close it needs to go when it switches the perimeter.

And as my picture illustrates, it should complete one entirely before going to another. It will make it save 2 travel times, thats allot of time savings.

 

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I agree that it is sometimes very annoying having Cura beginning one perimeter and then switching to another before finishing the first. However, I think the reason for this is the fact that a different speed can be specified for the outer perimeter. Cura could gain some intelligence by checking if a zero is set in that field and then adjust the order of the lines.

But back to your original problem. I don't see any reason right now why RetractWhileCombing should not add the retracts if the minimum length is sufficiently small. If you want me to check with your model, you may post a link to it or send it to Dim3nsioneer@gmx.ch.

 

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