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cor3ys

UM 2 Vase Printing help

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Hi Guys

I did a 20 hour print of a vase, The outside looks fine but the inside has stringing and lots of areas of rough flaky material...

It is water tight which is a good thing...

I am looking for advice on what i can do to make the inside of the vase look better ?

And also whats the best way to clean up the inside of this print i currently have ?

Finished Vase.

Vase

 

Internal stringing and rough areas of excess plastic.

string

https://docs.google.com/spreadsheet/pub?key=0Ao5tqNiR-cNudG90Zjl6UWpuUlZCNTEwMmQ5bzF1dlE&output=html

 

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Very beautiful. First I would seriously consider a different slicer. Vases are special cases. Try kisslicer maybe.

If you want to stick with Cura, look at the part in slice view and try to find these strings. They will show up as blue lines (blue means non-extruding). Check to see if there is a vertical movement shown in slice view - you need the latest cura 13.11 to see this for a UM2 print as there is a bug in Cura 13.10 where it doesn't show the vertical blue line on retraction for UM2 in slice view (even though retraction is there).

If there is no vertical line it is likely (possible) that Cura is not retracting. But if it is then the usual ways to fix stringing are available to you. Basically you can reduce stringing by lowering the temperature to as low as you can go. I would do a stringing test first. But if I want to eliminate stringing typically I just go to 190C and print slower - like 20mm/sec. This may not be an option for you as your Vase might take days to print - not sure. You might want to buy a UPS (uninterruptible power supply) before you start a multi-day print. Here's how I did my tests on stringing (first photo):

http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/

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I don't see the enable combing checkbox in your settings, or is it gone when using a UM2?.

That should follow the the oustside lines back, instead of crossing the internal of the vase.

I'd like cura to retract at all blue lines when moving from one point to another, but I have not found a solution for that yet.

To avoid stringing I stiil have a 13.04 version, Might not work for a UM2, but the downpoint is 13.04 gives a large Z-seem.

(layershift on the same radial point).

Following this topic for other input :)

 

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Hi Guys

Thanks for the tips,

gr5 i will look at Kisslicer only used cura as i have only been at 3d printing for a week now, i had already taken a look at your test subjects ;) about stringing and will give a lower temp ago...

3dcase yes i did have combing enabled just forgot to add it to my data sheet, i had also seen in another thread about cura 13.04 and something about jouis (did not spell that right but i think you know what i mean) but like you i don't think i can use it with a UM2...

 

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gr5 i will look at Kisslicer only used cura as i

 

Oh - now that I think about it I'm not sure if you can use kisslicer with UM2. I really don't know much about UM2 yet. I'm more a UM Original expert.

The "joris" setting is now called "spiralize" in Cura 13.11.

 

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Hi Guys

No i did not have the check box Spiiralize checked.. Wow you learn something new every day, i had no idea what that was for.. i can see another Vase coming this weekend will feed back the results with this box checked.....

 

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Yeah, Spiralize recreates the old Joris setting, and does two things: firstly it prints the outside skin in a continuous spiral, to eliminate the z-scar. Secondly, it disables the extra infill that Cura would otherwise add as needed on the inside of the object to thicken overhanging wall parts (and which cause the mess that you observed).

 

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I didn't get a usable print for multi-walled objects likes yours using the new spiralize feature. Cura seems to omit all other walls except a single one in the print and annoyingly does this for the bottom as well (make sure the shell thickness is about the nozzle size to get a solid bottom). It's hard to see even in the layer preview. A single wall might not be sufficient for a big vase like this (I'd use 3-5 perimeters on this one). My advise is to do a quick test print to check before starting anything big.

Just my experience, ymmv,

Denis

 

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Also, Spiralize will honor very wide shell thickness settings. How well it works will depend on your nozzle, and on not printing too fast... but you can specify a shell thickness of 1mm or more, and it will extrude that much plastic into its single wall.

 

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Also, Spiralize will honor very wide shell thickness settings. How well it works will depend on your nozzle, and on not printing too fast... but you can specify a shell thickness of 1mm or more, and it will extrude that much plastic into its single wall.

 

...if it can. How do I know how thick the extruded plastic strand will be with a .04 nozzle? Is there a way to compute it?

 

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Well it just raises the extrusion rate, and pumps the plastic out faster, so that it spreads out. If you go for too wide of a bead, then it will spread past the flat part of the nozzle tip, and make a mess. The standard UM nozzle tips are pretty narrow, but they should still be good for somewhere over 1mm.

The thing to bear in mind is that you need to still keep within the volume/sec limits of the extruder (8-10mm³/sec for a standard UM1). And in fact the pressures might be somewhat higher when extruding really wide, as the plastic has to flow further through a narrow gap between the print and the nozzle tip, and is probably cooling as it does so.

But for instance, if you extrude a normal nozzle-width bead at 100mm/s and 0.2mm layer height... that's going to be:

100 x 0.4 x 0.2 = 8mm³/s.

If you ask for a 1mm Spiralized edge, at the same layer height and speed, that's going to be extruding:

100 x 1.0 x 0.2 = 20mm³/second

That will almost certainly cause the standard extruder to fail, and grind the filament. But if you reduce the layer height or speed to compensate, and keep the volume per second down to 8 or so, you should be able to print a 1mm wide bead just fine with a standard nozzle.

(I recently posted about some odd defaults in Slic3r. If you don't force it to use a fixed width, it defaults to trying to make a 1.28mm bead for infill. It does work, provided you don't exceed the exruder capacity limits - which is all too easy to do, especially when you don't know that the slicer is suddenly asking for 3 times as much plastic per second as you expected it to.)

 

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