So maybe white is tougher to print....

[LePaul 331]

Everyone mentions white is tricky to get good results in.

My first print with ColorFabb PLA/PHA Standard White was good. Now this second print has a few things that make me wonder what else to tweak...

Note the top. I have the top/bottom thickness at 1.2mm

I printed on my UMO using the following settings:

Layer height 0.1

Printing Temp 200C

Speed: 35 mm/sec

Fill Density: 25%

No tangles...spool moves freely.

One thing I may have found...my caliper battery died so I couldn't measure the filament, so I left it at 2.85 I am really curious if the filament is +/- .05 And if that would make a difference?

[mendells 55]

Try another print with the exact same settings but with a different color and see what you get.

[LePaul 331]

That's certainly an option...I'm just surprised it did that.

[Dim3nsioneer 558]

Don't have that problem. But I use the pure stuff only (PLA without PHA). Cheers!

Translated: Maybe this is different for different filament brands?

Edited October 8, 2015 by Guest

[ultiarjan 1,223]

I've printed plenty spools of "makerpoint white PLA" (also a bit softer than regular pla) and it's prints fine, no issue compared to other colors.

[LePaul 331]

I wonder why the top came out the way it did. Even with 1.2mm top/bottom shell.

[mendells 55]

It looks like your getting underextrusion. There are a couple things you can do. You may want to increase your temp a little or slow down your print speed. Also check the tension in your belts to make sure there isn't any slack in the X-Y axis. With hard plastics like PLA when you get to the end of a spool the filament is tightly wound and can cause additional resistance inside the bowden tube. You can try swapping to a new roll and see if that solves the problem. I use "straighteners" on our machines and they make a big difference.

https://www.youmagine.com/designs/um2-filament-straightener

[LePaul 331]

Thank you for your reply

I tried another two prints last night.

This is a new spool of @ColorFabb PHA/PLA Standard White. The spool is moving freely, I've rotated it 2 or 3 times so the spool is slightly unwound for easier extruding.

Ulimaker Original

200 C

34 mm/sec

Bottom/Top thickness 1.2

Fill Density 24%

I used my caliper to measure the diameter and got a reading of 2.84 , 2.85 and 2.9 along a 6 inch stretch of filament. I stuck to 2.85

The flat piece went well.

The bigger piece is showing some overhang troubles. In Cura 15.04.2 I have support "Touching Build Plate" but apparently it didn't feel it needed any. The smaller piece did need supports and those printed.

I know others have had troubles with white filaments and since I have a large project in white coming up (BB-8 droid), I really want to sort out the right settings!

Here's some pictures

[ultiarjan 1,223]

In Cura 15.04.2 I have support "Touching Build Plate" but apparently it didn't feel it needed any.

It's a setting in the expert settings, you set the angle at which you want the support to kick in.

[LePaul 331]

@gr5 I wonder if poking the heat up a few ticks would help?

The small parts do great on these settings but the bigger ones....not so much.

As to the belts, well, they don't twang like a guitar string but don't appear loose. My UMO is noisy so I haven't detected anything new or problematic. I just did 18 prints in ColorFabb black in varying sizes that all came out well.

[LePaul 331]

 

In Cura 15.04.2 I have support "Touching Build Plate" but apparently it didn't feel it needed any.

It's a setting in the expert settings, you set the angle at which you want the support to kick in.

 

I've seen that setting and been hesitant to mess with it. Do most leave it at 45 or tick it down?

[ultiarjan 1,223]

Try printing a test object with different angles, with NO support, with the material you want to use, and then decide what angle you find acceptable without support..

Or do one with and one without support...

[mendells 55]

I try to print without supports whenever possible. If your angles are too steep you could try breaking the model up into multiple pieces or orienting it in such a way you don't need supports. I usually use 60 degrees for my prints. What are your fan speeds? Better cooling usually helps with steep overhangs.

[LePaul 331]

Fan setting are default ones. Fan comes on after first later

[peetersm 124]

About over hangs. On my UMO/UMO+ Try to have the over hang face the single fan.  over hangs on the down wind side always look a little droopy. Sometimes this is not possible thou.

And maybe go cooler, most of my colorFabb prints great at 190C. I am actually planning on opening my 1st box of colorFabb standard white today. So this post is great timing.

[ultiarjan 1,223]

and for the standard UM2 setup the left fan is better than the right ...

[LePaul 331]

I upped the temp to 215 and still bad underextrusion. I'm stumped on this one. I may go back to the Black filament, or Dutch Orange, that had worked well.

[gr5 2,235]

White prints pretty well for most areas (like walls) but it tends to be more liquidy. Less viscous. So it is more likely to leak/string and it doesn't do overhangs quite as well. But top surfaces should be fine. I tend to print white at a lower temp - maybe 15C lower. And then I end up also having to print slower because I'm afraid of underextrusion even if it's not necessarily a problem.

I think you had trouble on that top surface because it is over an overhang and it took a while for the layers to "catch up". Maybe if you rotate the part so the circle is down? or increase infill to 24%? Or higher?

[LePaul 331]

Hello @gr5

I do have infill set to 24%

I had printed at 200C and 30 mm/sec and had similar issues.

[LePaul 331]

I've seen you post this a few times...

Print slower and hotter! Here are top recommended speeds for .2mm layers (twice as fast for .1mm layers):

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

I am printing at 0.1 so using the above, that would translate to...

40mm/sec at 200C

60mm/sec at 210C

80mm/sec at 225C

100mm/sec at 240C

Maybe I should re-check the filament?

I did when I first loaded it and there seemed to be a few spots at 2.9 mm but some at 2.83 and 2.84, so I went with the average of 2.85

[peetersm 124]

yeah recheck the filament is a good idea. all the colorFabb I have is in the 2.75 to 2.80 range

[LePaul 331]

And that could explain, as I have seen in the reference guides, some of the underextrusion issues.

[gr5 2,235]

You only had underextrusion in that one spot - it's not because of the temp or speed or feeder - it's because the layers below aren't high enough. At least I'm 90% sure. having filament down to 2.5mm would be (2.85/2.5)^2 or 30% underextrusion - I suppose that might be enough to cause what you saw - but it would be a problem in the entire layer - not just that one spot. I really doubt this is a filament diameter issue.

I think it's just having trouble on the underside - maybe show a photo from the other side - I bet the layer looks pertty bad on the bottom side of that bad spot. Maybe if you could design some support structure underneath it would work out better.

I could be totally wrong but in the photo it looks like it's only underextruding in that one spot.

[LePaul 331]

I'll post a photo from the most recent attempt tonight. I meant to do so but was running late for work and have a pilot meeting tonight. Check back this evening

[SandervG 1,521]

I always thought white filament required a slightly higher temperature.

If you say 40mm/s 200ºC I would reply with 40mm/s 215ºC.

Every filament and brand has different 'perfect zone'.

About the overhang; I would think that area could be a little bit better.

(a higher resolution could help, dunno what fan duct you use and how well it is dialed in to cool the overhang?)