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printerfan

Minor flaws in my print

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I printed a skull the other day and here are the results. The detail in general is pretty good, but there are some imperfections on the top of the skull that I would prefer not to be there. I am working with an Ultimaker Original, no fan, and the room I print in is rather cold (57 degrees Fahrenheit), but I had a space heated set next to the printer as the cold temperature of the room seemed to make the PLA dry to quickly. Also, settings were at 50 m/s, .1 mm layer height, at .35 scale.

Any advice to help me get better prints would be much appreciated. :)

skull print 2

Skull print 1

 

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Change the fill density to above 25%, it will use a different algorithm that is much tighter. If your other thread is any indication and you have no fan, this will be the only way it'll help.

Also 0.8mm top bottom thickness. so you have 8 layers of material on top.

Pretty good print otherwise though!

 

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Okay time to update. The new settings listed below yielded the following prints:

Top/bottom thickness = .8

Shell thickness = .8

Fill density = 30%

Speed = 50 m/s

Layer height = .1

Scale = .35

Support: Brim

No Fan installed

 

skull print 4

skull 3

 

The top image shows a spiral like design at the top of the skull, how can I reduce/eliminate this defect?

 

The bottom image shows very rough, very stringy bottom. I used brim support, but even if I scrap the bottom layer it to try to remove the poor looking strands, it still looks bad. Any suggestions to resolve the roughness and stringing of the bottom of the print?

 

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A couple of suggestions ( from a beginer! )

The spiraling may be less noticable on the face ( it will tend to get lost in the other detail. It will always stand out more on a smooth surface). Try printing face up.

As Nallath says, the roughness on the overhang on the bottom is unavoidable. I've overcome this by cutting the model in 2, then gluing the prints together. This way, both halves can be printed without overhangs.

 

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Nallath are you recommending I reduce the top/bottom layer thickness to reduce the spiral effect at the top of the skull?

I have considered printing 2 pieces and gluing them together, but I saw a thread a month ago that showed someone with a heated glass bed creating perfectly flat bottoms on their prints. Ironically, I didn't save it and now that I'm printing its a issue I am having.

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Nallath are you recommending I reduce the top/bottom layer thickness to reduce the spiral effect at the top of the skull?

I have considered printing 2 pieces and gluing them together, but I saw a thread a month ago that showed someone with a heated glass bed creating perfectly flat bottoms on their prints. Ironically, I didn't save it and now that I'm printing its a issue I am having.

 

Just to clarify, 'thinner layers' as in your layer height. Not the top/bottom thickness. I think that's a good enough print, I would just fill the top and lightly sand it instead.

A glass bed does give you the ability to create relatively seamless joins if your model stays flat throughout the process. With blue tape this is not possible. If you do split your model in half, do it in a place that is not very noticable and supports your print direction. Make some holes/pegs registration marks for alignment.

 

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Valcrow, when you say a glass bed gives you seamless joins, is this because it results in such a flat bottom surface? If so, does the glass bed have to be heated?

Lepaul, I bought my Ultimaker Original used and it did not come with a fan. I need to install a fan, but I don't know which fan is the best, whether I should do dual or single fan, what shroud to print, ect. I will likely create another thread asking for fan advice.

 

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I reprinted the skull with the exact same settings as the last print; however, decreased the speed from 50 m/s-->40 m/s and increased the top/bottom thickness from .8-->.9.

The skull feels heavier and is slightly taller (likely from the increased top/bottom thickness), the overall resolution and print quality is essentially the same. The spiral design is somewhat less prominent, but I am not sure if it is due to the increased top/bottom thickness or simply individual print variation.

Should I try to increase the top/bottom thickness to 1.0 or higher to see if I can eliminate the spiral design?

 

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Yes the glass needs to be heated otherwise your print won't even begin to stick onto it. The resulting bottom is a perfectly smooth flat surface in which you can just glue together to another perfectly flat surface to create a somewhat seamless join.

I say somewhat because usually the bottom layer flares out just a tiny bit. Still MILES ahead of tape bed prints.

The spiral pattern will not go away no matter how much top/bottom layers you put. this is a function of the slicing on round object tops. The only thing that will make significant difference will be printing at smaller layer heights or rotating your part so that the flattest round part is not at the top.

 

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Well your nozzle size should be your physical nozzle size. Don't change that unless you're doing it for a specific purpose. (so 0.4mm)

I would do:

0.06 layer height (or 0.04 if you want to wait days)

35mm/s

200C on UM silver

Your other settings are ok as it is. For something that large I wouldn't do 0.04, there's almost no discernable difference between 0.04 and 0.06 except for a much longer wait time, and potential stringyness.

Note the top will still most likely melt (the spirally part)

If you're most concerned about the top spiral, just use the "cut off bottom" option in cura to sink the model into the ground and print JUST the top to see if you can get adequate results. No use printing the entire thing to be dissapointed at the end about the 'spiral'. The rest of the model looks like it printed pretty good already.

 

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Valcrow that is good advice, I didn't realize I could cut the top off the model and just print that part of it. As for the temperature, I have had to set the printer at 220 degrees for PLA. At 210 the extruded PLA appears to dry/harden before it can stick to the plate and other parts of the model. My room is cold, 54-57 degrees Farenheit, could that be the issue or could my thermocouple be off?

 

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I printed this crest from a picture. First I printed it flat:

flat.png

I you look close, there are plenty of flaws on the top edges.

 

I then printed it tilted to 30 degrees and rotated by 30 degrees:

angled

It needed a raft & support. Most of the un-wanted artifacts have gone.

 

 

 

print

 

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My theory is as follows:

The printer give it's best finish on vertical and horizontal surfaces. By tilting the model, I'm bringing the sides of the raised sections closer to vertical/horizontal and minimizing peaks which often result in blobs.

I did get some blobs, but far fewer than when printing flat.

 

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