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Print improval

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Hi everybody!

After receiving my UM2 yesterday I'm really impressed about it! In the weeks before I got my printer, I've read several topics about the best settings to print.

To be honest: I see so many different opinions and settings, I really do not know where to begin or what to change.

The basic UM robot printed fine with the default settings. So after that, I've tried to print a woman sculpture which I found on Thingiverse: http://www.thingiverse.com/thing:154019. (creating beauty with beauty... :wink: )

I left my settings at default, except for the buildplate. Reduced the temperature to 50 degrees. Scaled the model down to 5cm height.

I've tried two times. Unfortunately, both attempts failed at about the same height, because at that point the model disconnected from the buildplate. Did use 'Brim' as support type though.

For both the prints, there appears to be a problem at the upper part of the legs. It's not fluent there. Same goes for the lower backside. Further up it looks better.

I really wouldn't know what to change in order to improve. And more important, why? Can anybody set me in the right direction please?

Settings I have used:

Layer height: 0.06mm

Shell thickness: 0.8

Retraction enabled

Fill Bottom/Top thickness: 0.6mm

Fill density: 20%

Print speed: 50mm/s

Support type: Touching buildplate

Platform adhesion: Brim

Nozzle size: 0.4mm

Initial layer thickness: 0.3mm

Cut off object bottom: 0mm

Dual extrusion overlap: 0.15

Travel speed: 150.0

Bottom layer speed: 20

Infill speed: 0

Cooling: Minimal layer time 5 sec, cooling fan enabled.

In the printer, buildplate temperature set to 50 degrees.

20140128_182622.jpg http://s1.postimg.org/tp5nwp2qn/20140128_182635.jpg'>20140128_182635.jpg[/url]

Regards,

Richard

 

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50º is probably a bit low. I generally use a thin layer of glue, and 60º for the plate.

I'd start out printing slightly thicker layers. To be honest, after the test prints I've done lately, I'm not sure there's ever much of a need to go below 0.1mm layers - and certainly not while you're just figuring things out. Go for thicker layers, so things print quicker, and you can get through more iterations of your tests, faster.

Also, for a mostly convex shape like this, you shouldn't need any infill at all - just 0.8mm shell, and a bottom/top thickness that's at least 8 times your layer height should be fine.

You don't mention what print temperature you are using - if it's less than 230, I'd be inclined to try raising it to at least 230.

 

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Thank you Illuminarti!

I've read a post by Ian who said that he uses 50 degrees for the buildplate instead of 75. So I followed his example.

The temperatue was 210 by the way.

I will start right away and change the settings. I'll let you know the result. :-)

 

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It's a bit hard to see in the photos, but it looks like your brim threads aren't merged really well together - which suggests that your bed levelling might be a fraction high, so that your first layer just isn't going to stick really well, because the plastic is more laid onto the glass, than pressed into it.

So perhaps try re-running the bed leveling wizard, too.

 

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I think you're right. I'll re-level just in case.

Edit: Just re-leveled. Changed the layer height to 0.1

Bottom/Top thickness to 0.7mm

Fill density to 0

I left the print speed at 50mm/s

Buildplate at 60 degrees

Print temperature at 230.

Let's see what happens...

 

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Hahaha, in time, Yellowshark! First understanding the basics while the guys of Ultimaker are developing a dual extruder for the UM2. ;-)

But yes, when it's available I will be in line for it! Until then I've seen some very nice projects to try. Prints with support for example. Still a bit scary a model won't be as nice because of the connection with supports. But when I see the beautiful dragon of Illuminarti ( http://www.extrudable.me/2014/01/02/the-guy-with-the-dragon-part-2/ ) it's very tempting to give it a try!

Maybe in the near future, first some more simplified models... But thanks for the compliment!

 

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Next model, next challenge... :???:

I thought this would be an easy one, but unfortunately something went wrong again. This time I've tried to print a cilinder with a dragon on the surface. The cilinder itself already gave a problem, so I aborted the print. Somehow he created a gap in the cilinder at approx 1,5 cm height of the cilinder, while the first part was ok. The mesh of the 3D model itself is fine.

Printed the model with PLA blue with the following settings:

Layer height: 0.1mm

Shell thickness: 1.2mm

Retraction enabled

Bottom/Top thickness: 0.8

Fill density: 20%

Print speed: 50

Support type: Touching buildplate

Platform adhesion: Brim

Nozzle size: 0.4mm

Initial layer thickness: 0.3mm

Cut off object bottom: 0.0mm

Dual extrusion overlap: 0.15

Travel speed: 150.0

Bottom layer speed: 20

Infill speed: 20

Cooling fan enabled

Cura:

Temperature: 230 (read on the forum it's the best temperature for PLA blue)

Heated buildplate: 50

Anybody an idea?

20140129_210445.jpg

 

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1) Damn - it looks like underextrusion. You should put your finger on (or look directly at) the extruder when it gets to these bad layers and see if it skips backwards a 1/4 turn occasionally.

2) But maybe it's not - maybe it's a slicing error. Check that first - look at this part in layer view in cura and scroll slowly through these same layers - did Cura skip over a few layers maybe? This sort of thing happens all the time - it's typically fixed with the "fix horrible" settings. Probably the 4th checkbox.

If the problem is #1 I would slow to 30mm/sec and raise temp to 235C to put less pressure on the extruder for now. Many people are looking into this (including ultimaker) and this problem is not yet solved but you can work around it by printing at less volume. .1mm at 50mm/sec at 230C should be okay but if not then raise the temp a bit and slow it down a bit.

 

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I think it is problem nr 1. I'm printing a small example of the famous 'Yoda head', and I see some underextrusion. Reduced the speed and raised the temperature to see if it improves.

20140130_221902.jpg

Edit: Even then I had the problem. Raised again to 240 degrees. It seems to print a bit better now.

 

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When dealing with underextrusion you really have to post all 3 of these because any one of these can cause the problem: layer height, print speed, temperature. Just raising temp isn't enough if you are printing thick layers or at high speeds.

 

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Oh - I just advised you to raise temp due to underextrusion, but now it looks - well - not right. If there is underextrusion at 220C you will have to slow it down some more. Maybe 20mm/sec

You might want to try Cura as it's a pretty good slicer. The best tool for support is meshmixer:

http://www.extrudable.me/2013/12/28/meshmixer-2-0-best-newcomer-in-a-supporting-role/

pay particular attention to how to rotate your part in the "annoyances & limitaions" section and also note that there is a small error where he set layer height to "0.5" mm and it should be the layer height you print at e.g. .2 or .1mm.

 

 

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Have you checked the tiny screw that holds the knurled extruder bolt in place. Mine was a bit loose, causing occasional under extrusion. In fact you should check all your screws... and really really tighten them. I ruined a print or 5 before this was ok for me.

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Thanks for the advice Cor and Gr5, I will check the screws and reprint at 220 with 20mm/s.

I already use Cura as slicer though, haven't touched meshmixer yet. I will run a reprint tomorrow. Had a busy weekend, so my printer had some rest... ;-)

 

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