Looseness around holes

[JCD 28]

@Deve

I do'nt use octoprint, but with craftware you can study offline, without printing, the GCode and the movements, a top feature if you are working to do a post processing plugin to modify the way Cura is working

 

For instance, if you look when printing with Cura, on the top layer you have the lines, whose speed is print_speed, and around the holes you have

skin (outer_wall),and walls

Usually you put a speed for walls which is rather faster than the lines, maybe one thing explaining your problem

 

If you want to make a post process to change the speed on those part of the GCode you have to study the code to find what criteria to use to recognize the line of code to change either speed and/or extraction flow

 

 

[Deve 5]

I would just me happy to try what is working for you. If I had your settings, I would try it, and then we would have apples to apples comparison. If you are not having the same problem I am, that is encouraging because it means the settings in Cura are already there to resolve it.

[JCD 28]

As you say it's difficult to give all the parameters, but I have a few difference that matters

 

You have a lot too many walls in your model, so too many circles around the holes

 

For a usal piece try  the vertical wall 0.8 to 1.2 So you will have 2 or 3 circles around the holes

Idem for top/bottom thickness 0.8

If the piece is too weak with this you can make an infill with a higher percentage

Make the speeds the same (40mm/s) except the infill speed (80mm/s) and First layer speed 20mm/s

 

[Deve 5]

Thanks. I will try this. Also, you can see all of my parameters here. If anything sticks out other than what you have already observed, let me know! ? 

 

http://devestechnet.com/NewTech/HeatBed

 

[kmanstudios 1,120]

5 hours ago, Deve said:

...the point here is, while printers are different, to accomodate all of them (not a small task by any means and kudo's for you guys trying!)...

This overlooks the the fact that it is up to the manufacturer to supply a proper profile or experienced users. Team Cura and UM is going to support their product because that is the real goal. They are actually doing something nice by keeping it open source.

4 hours ago, JCD said:

It's the graphical result of the gcode instructions.

In a way, but it can also depend a lot on local graphical solutions per computer. For instance, I have seen the holes in display he shows, but it printed just fine too.

[Deve 5]

With that in mind and knowing how the manufacturer didn't step up, let me know if there is anything you need. Anything at all, I will jump right on getting you whatever is available. I am sure there are others who feel the same way.

[mnis 11]

@Deve
A short review with guesses and suggestions:
2 out of 3 machines do not have the problem with the holes, right?

If yes, in this case there is no direct problem with the Slicer Cura ...

Increasing the amount of material leads to a better result of the printed objects on the machine with the problem mentioned, right?

If yes, a lot of factors could cause this problem, such as:
- Incorrect setting of the E-Steps / The stepper motor may make finer steps with 0.9 instead of the usual 1.8 degrees per step, which means 50% less material flow...
- The knurled wheel of the feeder may have a smaller diameter.
- The Feeder stepper is too weak, or gets too little power and regularly loses steps.
- The selected material will shrink too much for some reason, even if side-by-side panels look good. This could indicate that something is wrong with the material or material transport.

I've used a lot of Cura versions over the years with always the same machine. The problem I've seen has happened only a few times, maybe 3 to 5 times in the entire time. And always there were the following things to solve the problem:

Feeder set too weak and strengthened / New material taken, problems with material flow at the HotEnd and / or the nozzle fixed / Nozzle diameter smaller than expected and other nozzle tried / Cooling way too aggressive and reduced to a Minimum / Too high temperature and printing speed for the selected material and both corrected.

Maybe I did not understand everything in the conversation, or read something too hastily, but heck, it does not hurt to repeat a few things. And if I'm wrong with my assumptions, maybe I can learn something more :-)

Edited June 6, 2018 by mnis

[kmanstudios 1,120]

43 minutes ago, Deve said:

With that in mind and knowing how the manufacturer didn't step up, let me know if there is anything you need. Anything at all, I will jump right on getting you whatever is available. I am sure there are others who feel the same way.

Once you get this solved, then I would suggest that you make sure to show results here, tag one of the Team UM members and then let it rip from that point. Too many manufacturers just pass off that responsibility and even send people to UM for problems when it is their machine that creates issues.

 

It is guys like you that are the true good guys in this and you efforts make other's live much better. :)

 

[Deve 5]

The problem happens on all three Anet A8s and all of the time. Some prints are better than others, but no, I cant pin it down to a specific machine. One uses Ramps 1.4 with adjustable stepper controller current. I have tried that route to no avail. I change my nozzle and feeder screws regularly as they need it. I am very meticulous in making sure everything is in perfect working order. I oil the system once a week since they run 24/7. I use a good PLA and have tried PLA from other vendors and this made no difference. I use the latest Marlin firmware and OctoPrint for moving my files remotely. Even when I used the stock Anet firmware on two machines and Marlin on the other, I still had the same problem with all three. A few days ago, it looked as if Printer #2 had this problem worse, but then today I ran #3 and it was worse. This has been a problem since I put the printers together two years ago.

 

The printers are more solidly put together than typical of this model because I understand the importance of a solid machine. I use high quality belts and make sure I use the latest Cura. What would be REALLY helpful is if we could find some A8 users who would take the rather large amount of time to record every setting so we can compare. I realize how hard this is, so I took high rez screen shots (it took 5 of them) to get all the settings so everyone can see. I do not blame Cura for this, however, I merely mentioned in the first place that it seems odd to me that there are 6 concentric circles around each hole (round or square) that persist through the infill and the top/bottom layers when a more solid method would be to change the top/bottom layers so that the line method was used right up to the edge of the hole.

 

Keep up the good work everyone... My hope is we can get to the bottom of this without anyone taking offense to my persistence.

[mnis 11]

1 hour ago, kmanstudios said:

In a way, but it can also depend a lot on local graphical solutions per computer. For instance, I have seen the holes in display he shows, but it printed just fine too.

That makes sense, because in the graphical view you can see how the machine moves and lays optimal tracks. But what is missing from all these calculations is the specific behavior of the chosen filament. I think to calculate this is a very big challenge :-)

[Deve 5]

Kman, my hope is the Team is already paying attention to this (why I posted). Two issues that need looking at by them..

 

1) We desperately need a way to print the settings out to a text file so we can share our settings easier. If we had that, we could save them a lot of time because we could compare between users and fix a lot of silly things before ever involving them. Who knows, this may be one of them, but its like pulling teeth to get anyone to share their settings because of how hard it is.

 

2) The top and bottom layers should be different from the infill. 6 concentric rings around each hole that allow me to push out a huge chunk of the print without much problem because of my issue seems wrong. Even if I didn't have this problem, it would make the work more solid so its a good idea anyway.

[kmanstudios 1,120]

15 minutes ago, Deve said:

We desperately need a way to print the settings out to a text file.....

This has actually been discussed before for a variety of reasons. If I find the thread, I will post a link here to let you put in your perspective as it does present a good case. And, the fact that you are understanding of the issues does help I believe.

 

But, I am tagging @SandervG just to make sure that it is seen. He would be able to best advise.

[mnis 11]

2 hours ago, Deve said:

1) We desperately need a way to print the settings out to a text file so we can share our settings easier.

 

I know a simple solution for Windows users to display the content largely formatted, and thus meaningful to print. The applications already available in Windows 10 are sufficient for this. I have tested the following methods with the general Cura profiles and get up to 100 settings in alphabetical order depending on the Cura version. However, it seems that if there are multiple profiles, it becomes more confusing and there are only deviations from the root profile.

Anyway ... maybe it will help you a little ...

Cura 3.3.1 (about 100 settings in alphabetical order)
Activate and export your settings profile of the desired machine in a download directory of your choice. You will get a file in this format: FILENAME.curaprofile; With the right mouse button you choose: Open with; and then the program; WordPad; If you have not already done so, choose a UniCode font if possible. And BAM, there they are listed the settings nice and clean :-)

Cura 15.04.6 (About 80 settings unsorted plus many GCodes with short notes)
Here you get after saving the profile a file in this format: FILENAME.ini, the next procedure is identical to the previous one.

Edited June 7, 2018 by mnis

[SandervG 1,521]

10 hours ago, kmanstudios said:

This has actually been discussed before for a variety of reasons. If I find the thread, I will post a link here to let you put in your perspective as it does present a good case. And, the fact that you are understanding of the issues does help I believe.

 

But, I am tagging @SandervG just to make sure that it is seen. He would be able to best advise.

 

You may want to read / get involved here. I also thought there was another thread about it, but I also didn't find it just now. 

[SandervG 1,521]

This is the other thread I couldn't find earlier

[Deve 5]

JCD, I would like to get that A8 stl file you mentioned earlier.

 

"Otherwise if you want a smarter working space, I made an stl file to put in the Cura folder, to have a picture of the printer on the cube where cura put the models (like the ones existing for the ultimaker printers)"

 

I could use that. Thanks!

[JCD 28]

@ Deve (and all of you)

 

in the forum Here  the files to get a picture of the Anet A8

 

Also a bunch of new things (choice between Direct and Remote Extruder, the complete list of the settings values at the beginning of the file)

[JCD 28]

Maybe I got the trick !!

 

It's in the shell settings

 

You have not check Optimize wall printing order. Cura is printing the walls of each holes in that order hole1 wall1 then hole2 wall1....then  hole1 wall2, hole2 wall2...

 

So the nozzle is travelling from one hole to another (with or without retraction), and the pressure in the nozzle is making a little part of the plastic flowing outside (thus making very small lines on the print duriing the travel), and when it begin to print after the travel the flow is a little smaller for a while (while the pressure is going up), so it like an underextruding

 

If you check the Optimize the order will be hole1 wall1, hole1 wall2... hole2 wall1, hole2 wall2... thus there will be less travel and no more 'under extrusion' effect.

 

But the other problem is the 2 extra walls and alternate extra wall you have, because they are not managed by the optimize setting (i Think it will be better if the Team modify this). Thus you have to put 0 extra wall

 

You can keep alernate extra wall as when there is 0 extra wall, it is correctly managed by the optimize setting.

 

The infill ratio is high so I think the firmness of the walls will not be a problem

[Deve 5]

Thanks for that. I will keep an eye on my prints to see if that helps. 

[oliverclarke 0]

Im almost certain this is an issue with the slicer, ive just come to accept that cura cannot handle holes and top layers very well. Its almost as if it needs to just slow down a little when doing to the walls. 

 

If there is something I am missing i would love to hear it. Everything else Cura does, it does perfectly for me. 

[AbeFM 35]

There's an issue where CURA often chooses to print stuff in mid air, because there is "support" on the layer below - but it is not below where the extrusion happens.

 

Please make an explicit call stating your interest in having top surface features printed above existing infill/support. It's been mentioned in a few other threads and the official response is that it is not a priority. I don't want to raise a stink, but if all interested people would say that they would like features-above-infill to print correctly, they may move it up their priority list.

 

 

On 6/12/2018 at 12:29 AM, JCD said:

Maybe I got the trick !!

 

You have not check Optimize wall printing order. Cura is printing the walls of each holes in that order hole1 wall1 then hole2 wall1....then  hole1 wall2, hole2 wall2...

 

OMG! Thanks! I will be trying that.

[henderpa 0]

I have this problem as well, all the time, with Cura. I don’t experience it when testing other slicers. I don’t know what’s causing it, but I know what it isn’t (and I’ve searched and combed through various forum threads with no solution). Here's what I've eliminated so far:

 

—"Optimize Wall Printing Order" does not fix this problem for me, whether it’s checked on or off makes no discernible difference to this.

 

—It happens with curved lines/circles, but doesn’t happen with straight lines. So, amping up the flow rate/extrusion on walls does not fix the problem, because to see any difference I would have to turn it by 25% and by then all other walls (straight lines) become massively overextruded.

 

—It’s not a speed issue. I have tried printing at 20mm/s, 40, 60, 100—it happens at all speeds (it’s slightly worse at very high speeds, but it’s bad always).

 

—It’s not a gcode flavour mismatch; I’m running Marlin and have set Cura to Marlin firmware (as I have any other applicable slicers I’ve been using to test). Note: this was also happening on stock firmware, which is why I switched to Marlin in the first place.

 

—It’s not my hardware, given that the problem is limited to Cura slicer.

 

—It’s not layer height; I have tried 0.1mm to 0.4, and the only difference is how many layers have gaps, not the size of the gaps.

 

—It’s not nozzle width. I’m careful to set my nozzle width properly and have tried 0.2mm to 0.6mm nozzles. It persists on all of them (only the size of gap changes).

 

—It’s not wall width. I can set that to 5mm, it still will form a gap around the 5mm curved line.

 

—It’s not temperature; it happens across the range. Also, I’ve tried different cooling amounts (fan speeds).

 

—It’s not the filament; it happens with PLA, PETG, and ABS, and across manufacturers.

 

—If the solution is retraction/combing/coasting settings (big "if), then it’s some very precise combo of those three. I’ve tried a range of retraction/comb/coast settings on the above filaments and the issue persists across those ranges.

 

—I’ve tried "ironing" the top surface but this is a bandaid solution—the gaps exist throughout the print, just not in that one top ironed layer. So it can produce an okay surface, but it doesn’t fix the underlying structural problem.

 

—It’s not ambient moisture. Filaments are printed direct from a drier or from the spool holder if recently dried.

 

—It’s not the enclosure around the printer; it was happening before I put an enclosure around it (which I thought would help solve the issue).

 

—It’s not bed adhesion or leveling. This has happened across multiple levelings and in any case, it happens even at the top of tall prints where the circular hole is only in the top few layers.
______
 

Any other likely candidates for what might be causing this? Such a shame that an otherwise great piece of software would have trouble with such a basic thing.

[GregValiant 1,251]

There are numerous flow settings for the various areas of a print under "Material".

Nobody has mentioned Line Width.  Generally it is the nozzle width, but it can be set otherwise.  Smaller (Ex .35mm) would move the lines closer together.  I believe it has an effect on flow.

If the firmware is Marlin then under Tune there should be a global setting for Flow % (scroll down to the bottom).  That can be adjusted on the fly.

You could also put an M221 S110 at the start of the Gcode to set the global flow to 110%.  That is more of a one-shot deal if you can't adjust on-the-fly while printing.

[henderpa 0]

Hi Greg, thanks. It’s a good thought, but I have actually tried a range of line widths with each nozzle, up to 0.1mm in either direction (printing 0.4mm to 0.6mm on a 0.5mm nozzle, I mean). I’ve adjusted flow as well, but as I point out turning up flow even just for inner walls causes will then cause overextrusion on straight lines (excess filament buildup, stringing, messy prints everywhere else).

[GregValiant 1,251]

I have had this same problem occasionally.  Unfortunately, it comes and goes and I haven't really figured out why.

I tend to have a single profile that I use for everything.  I change it as I go from PETG to PLA and from model to model.  Every once in a while I hit a combination that causes this problem.  Then I slice a different model with some different settings and magically the problem goes away.