Slicing and Print Quality Issues..bit of help required

stratogavster · Post by **stratogavster** » Tue Dec 04, 2012 9:59 pm

Hi All,

Have been experimenting with the high quality profile and normal profile in SFACT since my great success with the pre configured 'octopus' (confirmed to have used the high quality profile).

Not having much luck....

Had the dimensional issues.....but after re-printing a new gcode using Normal quality I get lots of blobbing and holes in the surface!

A close look at the images shows the areas of interest. The thinner print shows a lot of blobbing (actually used high quality profile for this), while the taller object shows actual tiny holes!!

Any ideas what is causing these issues? Since the octopus have been confirmed to have used the untouched high quality profile, why do I see these issues?

Temp has been around 195 - 197 and speed around 70% of the programmed speed.

stratogavster · Post by **stratogavster** » Tue Dec 04, 2012 11:23 pm

Quick update.....new sliced file with similar settings depicts the gaps i'm seeing!!

Any ideas what they are and which part of SFACT can get rid of these?

aikx · Post by **aikx** » Wed Dec 05, 2012 12:37 am

Jitter? :http://fabmetheus.crsndoo.com/wiki/inde ... rge_Jitter

Trnquill · Post by **Trnquill** » Wed Dec 05, 2012 10:30 am

Check the "Clip" parameters, too.

stratogavster · Post by **stratogavster** » Wed Dec 05, 2012 11:38 am

Thanks for the tips!! will give them a go!!

Managed to get rid of some of this by changing printing strategy.....I printed loops - infill - perimeter

This gave much better results straight away!

YouTube · Post by **gfeliksdal** » Wed Dec 05, 2012 6:25 pm

I got the blobs too, but mostly when the temp is too hot or when printing a large build plate. I observed it mostly happens right after a long non-print move. During a long movement the filament inside the nozzle will have heated up more than usual and it starts printing at a new position nearby. This can be minimized by having very high speed non-print moves. This is setup in SFACT (130mm/s), but not always effective during printing for some reason.

When printing from inside to the outside, you will have this same blobbing, but it is in the inside of the part so you don't see it. Could you show us the results of the changed printing strategy?

stratogavster · Post by **stratogavster** » Wed Dec 05, 2012 8:27 pm

Here you go...images...

The blobbing is still there but it is less pronounced and only is a specific area....so a repeatable phenomenon. Hopefully one that can be removed?

Is there room for improvement in the retraction and priming settings perhaps?

stratogavster · Post by **stratogavster** » Wed Dec 05, 2012 10:59 pm

Have been tweaking the following parameters:

Profile based on 'Production, No Support, Normal Fill'

CLIP
COMB
DIMENSION [RETRACTION]
FILL [WHAT ORDER TO PRINT]
JITTER
LASH

Results so far....partially completed prints....before and after....immediate restart no mechanical tweaking

'Before' shows prominent blobs as previous sliced parts, but also shows 'waves' throughout the print (my first thoughts are these are mechanical issues?) Z wobble is very prominent also and is at regular intervals through the part height (not measured them exactly).

'After' uses my first attempt at making sizeable changes to the profile...and it seems better to me!....

First off it shows a distinct randomised spread of perimeter start points and they don't 'blob' as much and the gap seems neater.

I used CLIP to try and minimise the gap size by joining the perimeter to the loop smoothly. Not sure if it did anything. (Clip over... 0.01, Threshold 10)

Turned on COMB

Made RETRACTION much faster and longer (100mm/s retract 3.0mm, restart -0.5mm)

Tried FILL in the Loops - Infill - Perimeter mode

JITTER set to 50

LASH 0.03 and 0.03

This is only one of 6 'tweaked' files i'm testing.....will try and post more results

This stuff is black magic!

stratogavster · Post by **stratogavster** » Thu Dec 06, 2012 11:43 pm

More fun and testing....still trying to get rid of those bumps and blobs...but getting a lot better from only one round of inexperienced tweaking.....

This time using SKIN......Configured to leave fill layers untouched and wall thickness untouched but perimeter layers half height (thus 0.1mm). My attempt to mitigate the perimeter start blobs further....

Result: Nicer finish and not that much extra print time but sadly it never printed the final finishing top infill layer for some reason?

Comments: My main tweak I did before any of the others was the extrusion width. I changed it from 0.38mm to a figure that matches what I measure (0.4mm) but also found that most profiles I had, had a disparity between the same setting that appears on 2 different areas of SFACT, one said 0.38mm the other 0.4mm. Since matching them at 0.4mm my hole dimensions are dam dam close now!! -0.1mm.....they are still not round! but the X and Y and close

and the print quality has gone up!

Images below of results....I can get the perimeter start points to scatter but they leave gaps and splodges still....I think I can get rid of them....but i'm thinking now that the horrible Z wobble I get needs to be sorted first! this appears to be pretty bad....especially with vertical walled parts...

Other artefacts that seem to be holding me back with SFACT tuning is noise / ringing / ripples along X and Y. New V1.5 sides should help providing they are of a tight tolerance, though thinking the pulley teeth are propagating through as significant vibrations?

All adding up to poorly placed perimeter starts and thus blobs?....

satoer · Post by **satoer** » Fri Dec 07, 2012 5:09 pm

Great thing you're doing here stratogavster! If you find the perfect settings, please share the profiles