Still problems with small fills
October 29, 2013 05:54AM
Hi,

I have still problems with small infills. I am slicing with slic3er 0.9.9-dev, which worked great so far.
But for some reason, slic3r thinks, it cannot fit in a filling to the small wade gear , for example. Everything else seems to be perfectly calibrated at the printer but I just cannot get it to fill these fine structures.
Someone gave me the hint to change the infill ratio in slicer, but whatever I select, it changes only the infill of "normal" massive objects using honeycomb etc, but never changes the behaviour with fine structures.

Any idea, hint or maybe even a solution is highly appreciated smiling smiley

thanks!
Attachments:
open | download - gear1.jpg (311.7 KB)
open | download - gear2.jpg (249.6 KB)
Re: Still problems with small fills
October 29, 2013 06:15AM
How many shells/perimeters are you printing with?

More than one might be the problem. Seriously, if you are printing machine parts, you need to use Skeinforge to make them dimensionally accurate.

Regards,
Neil Darlow


I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.
Re: Still problems with small fills
October 29, 2013 06:17AM
I use the default of 3 perimeters....
I will try and use only one. thanks for the hint.

Really? You mean, slic3r does not make accurate dimensions? Ôo
Re: Still problems with small fills
October 29, 2013 10:48AM
I switched to 1 perimeter, it seems to be marginally better, now slic3r spat one tiny spot of filament into the teeth of the gear. but so small, it hardly is visible :/

I cannot find windows executables for skeinforge, only python sources :/
Re: Still problems with small fills
October 29, 2013 11:04AM
You have to install python on you pc to run skeinforge.py which is the actual application, there are indeed no executable files. This makes skeinforge look extra mean winking smiley
Re: Still problems with small fills
October 29, 2013 12:31PM
Python is an interpreted scripting language so you don't need a Windows executable. The source will run on any platform with Python 2.x installed, not Python 3.x. It can be made into a stand alone Windows executable but then it becomes platform specific and cannot be modified or examined.

Edited 1 time(s). Last edit at 10/29/2013 12:32PM by nophead.


[www.hydraraptor.blogspot.com]
Re: Still problems with small fills
October 30, 2013 07:34AM
I installed Python 2.7.5 and started skeinforge and.... holy crap! from what century is this tool? 1985? grinning smiley
the whole product seems to be completely unusable.
Is there some kind of howto for setting this dinosaur up and getting it to slice with the mendel90?
Re: Still problems with small fills
October 30, 2013 09:54AM
Have you followed the instructions in the Mendel90 manual? I managed to print fine from the included instructions. I've not yet tried slic3r
Re: Still problems with small fills
October 30, 2013 10:52AM
oops, somehow I must have blocked that information in the manual from my mind grinning smiley
thanks ,will check it.
Re: Still problems with small fills
October 30, 2013 02:04PM
hm nanual does not say much about skeinforge.
I tried to get it to work but so far the mendel creates only weird noise and snail-like movements. I wonder how one can get along with this software...
The wiki is also not very helpful if coming from slic3r...... sad smiley
Re: Still problems with small fills
October 30, 2013 02:53PM
The best thing to do is to go to Nopheads repository at github and download as zip the files from Skeinforge50plus folder (if that version was not supplied on the sd card of the kit). These are the latest files for the application (so you'll have the new cooling settings). Then use the .skeinforge Folder from the sd or github (mendel90 master directory I believe) and copy it to the directory c:\users\user. (if you're using Windows os). Overwrite the folder which is there from a previous version if it is there. If you've done all this then you now have Nopheads new profiles for slicing your files with skeinforge. These are the PLA 0.2 and 0.3 profiles. With these profiles you can slice files giving good results from the get go without having to touch the settings. At least it will give you a good starting point.

Edited 1 time(s). Last edit at 10/30/2013 03:27PM by Nilez.
Re: Still problems with small fills
October 31, 2013 05:40PM
As everybody (especially nophead in several threads *g*) is pushing me towards skeinforge, I will give it another try, following your tips, Nilez.
Instead of copying the profiles and alterations directory into my user, I had to copy it into the skeinforge_application folder.
I then loaded a STL file and it exported something and it seems to be printing it, but very fast so the bottom layer does not seem to be sticking to the bed when going edges.
I am afraid to change anything in the settings grinning smiley

edit: and it seems to be using to much material. Infills ooze out over the actual layer and create rough surfaces for the next layer.

Edited 1 time(s). Last edit at 10/31/2013 05:54PM by muelli.
Re: Still problems with small fills
October 31, 2013 06:26PM
Ok, so you are now able to select PLA 0.2 and 0.3 from the profile selection menu at the upper left corner of the screen? It prints at normal (slower) speeds with me and the right amount of material is extruded. I haven't touched settings except for the infill ratio, so something is not quite right with the way it behaves in your situation.
Re: Still problems with small fills
October 31, 2013 06:38PM
Yes, I can select PLA profiles. Right now it prints using the PLA 0.2 profile. Once again, very fast. Using slic3r, everything is much slower.
I fiddled around with the PLA dimensions but it still uses to much filament which makes a thick and rough surface.
I will make a video tomorrow and upload it to youtube, so you anybody able to help can take a look.
But now, I have had enough for today grinning smiley

So far, thanks for your help!
Re: Still problems with small fills
October 31, 2013 07:53PM
The first layer speed is defined on the Speed tab and is half the normal speed, IIRC 20mm/s. You can make it as slow as you want but I don't understand why you would need it slower than everybody else with a Mendel90.

The flow rate will be spot on if you calibrated your extruder and your Z axis correctly.

The advantage of Skeinforge is you can specify almost everything whereas other slicers try to "simply" things by taking it out of your control, That would be good if the authors understood the process and the maths behind it but some clearly don't.


[www.hydraraptor.blogspot.com]
Re: Still problems with small fills
October 31, 2013 07:54PM
Yeah there's certainly a lot to take in if you're a beginner. I'm riding the 3dprinting learning curve at the moment as well. Luckily we know we have a great printer and awesome folks here at the forum.
Re: Still problems with small fills
November 01, 2013 04:27AM
nophead:

i calibrated my extruder if i extrude 20mm, it extrudes 20mm. in slicer or kisslicer it works. shouldnt it work in skeinforge then too?
however, i have to set extrusion modifier to 0.93 in slicer, but cannot find that option in skeinforge.
it also does not reduce extrusion temp after the first layer, i do not understand why. i will play around with it a little more today.
Re: Still problems with small fills
November 01, 2013 06:30AM
If you read the manual is says to calibrate the extruder with 100mm. 20mm is too short to measure accurately. Also if you have set an extrusion multiplier of 0.93 then that shows it is extruding too much.

There is a similar bodge factor in Skeinforge, Filament packing density on the Dimension tab but it is easier to just set the correct E steps per MM and then let the maths work everything out rather than using trial an error.


[www.hydraraptor.blogspot.com]
Re: Still problems with small fills
November 01, 2013 06:41AM
OK, will do it again with 100mm! thanks.
I read a lot about the X/Y steps and calibration of these. Is this already pre-calibrated in the firmware?

Edited 1 time(s). Last edit at 11/01/2013 06:42AM by muelli.
Re: Still problems with small fills
November 01, 2013 08:47AM
Yes it is calibrated assuming the belt pitch is correct. You can tweak it by printing an object with a large feature and a small feature and use simultaneous equations to separate the movement error and part shrinkage from the outline offset error. For most things it is close enough to just use the belt pitch.


[www.hydraraptor.blogspot.com]
Re: Still problems with small fills
November 01, 2013 09:34AM
I have re-calibrated the extruder steps with 100mm extrude liek in the manual. After doing it a few times, I come now close to the capabilities of my (cheap) digital calipers, so I think this might be the best I can do.
Again, I checked the filament diameter (which in average is quite close to 3.0mm) and fed this into skeinforge with filament packing densitiy of 1.
I then printed my testobject again with the same results.
The infills are "oozing" where the extruder returns to draw the next infill line. Plus, the whole print looks...messy. I do not know how to express it.... it looks unclean. edges overshooting, walls not straight etc....
I am afraid I am doing something seriously wrong.

edit: I attached two pictures, I hope you can see it.

Edited 1 time(s). Last edit at 11/01/2013 09:52AM by muelli.
Attachments:
open | download - rough1.jpg (164.3 KB)
open | download - rough2.jpg (249.6 KB)
Re: Still problems with small fills
November 01, 2013 10:10AM
Maybe the tip of the hotend scrapes the layer because the z home point is not set right in the firmware?
Re: Still problems with small fills
November 01, 2013 11:12AM
wouldn't that impact on any slicer?
and only on the first few layers?
Re: Still problems with small fills
November 01, 2013 12:19PM
Did you get a good print with the android test gcode and sample PLA provided?

It is hard to see what is wrong from those photos. Is that different filament because the PLA provided is more like 2.85mm not 3mm.


[www.hydraraptor.blogspot.com]
Re: Still problems with small fills
November 01, 2013 12:23PM
Muelli, you're right, that should indeed have given a problem with any slicer
Re: Still problems with small fills
November 01, 2013 01:31PM
@nophead: this is not the faberdashery filament. It is new one which is more close to 3mm
However the android printed well, but i sliced it with slicer/pronterface

I just sliced this lithopane with slic3r and printed it, it is extremely layer and infill sensitive.
[www.thingiverse.com]
It printed great!
Seems to be a setting problem in skeinforge....
Re: Still problems with small fills
November 01, 2013 03:05PM
The settings released with the kit are correct for the PLA supplied with it. The idea is that you follow the instructions which culminate in printing the pre-sliced android. If that comes out well you know the machine is properly calibrated. Then you slice something with the setting provided and it should come out just as well.

As you have skipped those steps and used different slicers and plastic it is very hard to say what it wrong. Also the pictures need to be better quality to diagnose it.


[www.hydraraptor.blogspot.com]
Re: Still problems with small fills
November 01, 2013 03:32PM
I followed the manual in that point and uploaded the android.gcode and printed using pronterface.
that came out quite like the picture in the manual.

I will try to get a better camera, I just have a cell phone at hand sad smiley

Edited 1 time(s). Last edit at 11/01/2013 03:32PM by muelli.
Re: Still problems with small fills
November 03, 2013 08:43AM
I got another camera and took a macro picture of the testobject.
I hope it is now easier to see what I talk about smiling smiley
Attachments:
open | download - macro.png (261.3 KB)
Re: Still problems with small fills
November 03, 2013 11:02AM
muelli: re-take the pic either with a tripod from above or set something up that can take the pic from above. Then take the pic with the timer function, to minimise shaking. This pic is still hard to see detail.
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