Print quality help please

[qmaker 29]

Can someone give me a quick analysis of whether my issue here is a result of my settings in Cura or a hardware/temperature issue.

Cura settings are as follows

layer height .15

shell thickness1

bottom/top thickness 20

print speed 40

This is a full dimension build 28 hour print.

I am using ColorFabb at 210 temp and 65 buildplate temp

Perhaps I should drop my layer height for better quality. I expected layering but not the gaps....

 

[pm_dude 27]

Hi,

This looks like underextrusion and could be caused by low temp. Try at 220C for a small section.

Normally you should be able to do it at 210C so you may be having some other issue with the nozzle, teflon insulator or other parts.

How many print hours do you have on your UM2? are you still running with the original nozzle and teflon piece? did you do any modifications to your printer?

 

[x3nomorph 0]

Hi,

you said you use the ColorFabb filament, is this the XT white or normal white?

If its XT then you should rise the temp to 240°C-250°C

 

[qmaker 29]

Thanks guys, I looked back on some previous prints and see some of the same issues. These were done with a different PLA. I do think that maybe the problem may be compounded by the temperature, but suspect that it is more likely an underextrusion issue due to hardware.

I have noticed a couple of times that when I did the atomic method and went to pull the old material out that it was tightl in the nozzle end of my Bowden tube. I measured the diameter of the filament and it was fine. Do you think my bowden tube could have shrunk due to heat and is making it difficult for the filament to push through/

Is there a counter that tells how many print hours are on my machine?

I am using the original nozzle and teflon, no other mods. Is there a general maintenance guide as to how often to change the nozzle or teflon insulator?

Should I also consider using one of the extruders that others here have come up with?

I am using normal white not xt.

Thanks

 

[pm_dude 27]

On the UM controller you have a counter in the Maintenance/Advanced menu

[qmaker 29]

Heres where I am at.

Printing 291:42 258M

I went back through my pile of bad prints just to see and saw that I had a similar issue on a print awhile back using a different PLA. After thinking about it,that is the reason I switched to the Colorfabb. I thought maybe this brown PLA was giving me problems. I did get a better print out of it after switching to colorfabb, but still had some of the same issues.

 

I did have several prints in between the brown pla and the colorfabb that printed quite nicely. This is why I also suspected it could be just an issue with my Gcode.

 

Thanks,

 

[pm_dude 27]

In your settings you say shell:1. If you have a default nozzle on your UM2 the your nozzle size is 0.4mm. Make sure the shell represent a multiplier or the nozzle size. In your currrent case Cura still do 2 perimeters for your shell but increase the flow the clear the extra 0.1mm missing for each. Try using 0.8mm instead.

On the top thickness you wrote 20. Do you really put 20mm of top/bottom shell? that is really a lot. You may as well put 100% infill instead. Normally a top/bottom shell between 0,8mm and 1.2mm is enough. You want around 8 to 10 layers to be printed in order to properly cap a surface.

Have you tried printing at different temp?

 

[qmaker 29]

thanks, I will re-check the settings and adjust as you mentioned. I will also up the temp and see where we are at.

Thanks for the tips. I will let you know how it all works.

By the way. Do you think that I need to replace the teflon insulator based on my machine hours?

 

[DidierKlein 729]

I was thinking like pm_dude about the shell thickness.

I use colorfabb a lot and 210°c works fine with the other settings.

But also be aware that white is one of the hardest colors to print in my opinion (probably due of the pigment to have white).

 

[gr5 2,172]

I'm pretty sure the "1mm shell" is the biggest problem. There are limits to how much pressure the feeder can generate to squeeze the PLA out and asking for a 1mm shell means two .5mm passes which is a 125% flow rate into a tight space between the nozzle shoulder and the layer below.

The printer *can* do 1mm shell but you have to print either a bit hotter or slower.

In addition your underextrusion was partly intermittent - probably due to the filament spooling. I strongly recommend you put the filament on the floor. The brown parts had severe underextrusion - much worse than the white part. They were probably around 50% equivalent flow. Or less. Maybe 30%. In other words you were getting half to 1/3 of the needed pla. Putting filament spool on the floor reduces the friction enough to make a big difference when you are printing "on the edge" of ability.

 

[qmaker 29]

Hey guys, I am printing now at 218 degrees, .8 shell and things are looking much better!!!! I can't believe I had this set wrong. I even recall reading setting it as a multiple of the tip diameter somewhere along the way and then either forgot or..... Is it true that certain color PLA prints nicer than others? What colors print well and what colors do not?

I am still working on a good spool holder, perhaps I will try just putting it down on the floor. I made a spool holder that I am using now, but I think it is causing tension as well.

 

[qmaker 29]

Also I thought I would share that I have been having trouble getting successful prints from this piece due to the long overhangs... I purchased a 3d doodler for my daughter and used it a few times to reinforce some of the struts that I had made in Meshmixer that kept failing. Not ideal, but it worked great. A few extra supports from strut to strut and things were solid.

 

[nigel-johnson 1]

White is definitely one of the hardest filaments to print due to the additives. I'm not a keen supporter of upping the temperature because of oozing and i was finding that printing at 220C was still a problem with most of the filaments I was using. I tracked (a significant part of it) back to the spool holder and the tension it caused with the feeder. I now have a set of rollers at 90 degrees to the old spool holder and the filament goes directly off the spool into the feeder. The friction is so low that when retraction happens, a new 2.2KG spool rewinds as well. Anyway, I have not had any big under extrusion issues since in any of the filaments, but then I print slow - 20mm/s for small things at 195C for ColorFabb Naturel and if I have a larger object I use 210C with 40mm/s infill (still 20mm/s outer shell).

I predominantly use ColorFabb Naturel for anything I don't care about the color of. It's a nice enough colour, but it's very predictable and easy to work. The ColorFabb Flourescent/Lime green and light brown are also really nice to print with as well.

Leaf green and black are ok, but they do produce more uneven surfaces for some reason, certainly where there is a significant change between one layer and the next.

The hardest to work with are the white and the exotics like glowfill and bamboofill. I have some clear XT, but I'm too scared to try it

I have tried most of the PLA/PHA colours from ColorFabb but I haven't used them enough since working out the optimum calibration for my printer (and using the new spool holder).

I hope some of that helps.

 

[qmaker 29]

Thanks for the tips and information. Did you create a spool that has bearings etc.. or you have created a solid spool holder like the original just on a 90• angle?

Also you mention Naturel, does it seem to print significantly better than white? It would be interesting to see the same model with same settings printed in the various filaments.