Should I even complain?

[lately 0]

I've had an Ultimaker Original for a year and a half now and as a 3D printing novice have had an overwhelmingly positive experience with the printer. However, I'm getting to the point now where I'm wondering if there is more that I can do to improve the quality of my prints.

Most of what we print are busts of friends created using a Sense3D handheld scanner. While the stringing from these prints is not terrible there are a few issues I'm wondering if I can mitigate without significantly increasing print time.

 

As I mentioned above the stringing is pretty minor but what I would like to remedy are the weird extrusions that seems to be more than stringing (ex. the plastic sticking out of the cheek of the figure on the right).

 

 

In this view my concern has more to do with the bumps on the side of the head of the figure on the right. My assumption is that this is where the nozzle "lands" as it makes the jump from one head to the other. And, while not a big deal since it is part of the scaffold, I wonder if the stringing visible on the chin scaffold is symptomatic of the overall issue.

 

I've been wondering if the printer might be very slightly over extruding as I often find that the brim is harder to remove than it has been in the past. Are there some simple steps I can take to possibly mitigate these issues? Will adjusting the flow rate help with these issues? Thanks.

 

PRINTER: Ultimaker Original

FILAMENT: ColorFabb PLA/PHA

TEMP: 210C

LAYER HEIGHT: .1 mm

SPEED: 50 mm/s

RETRACTION: Enabled

TRAVEL SPEED: 150.00 mm/s

 

[pm_dude 27]

Hi,

Welcome to the forum! Thanks for posting the print settings you use.

Have you considered reducing the nozzle temp or playing with the retraction settings? Longer retraction should reduce strings and spikes in your print. I don't have an UM1 but I believe it should be able to print at lower temp.

Try printing 1 or 2 small cylinder of 20-30mm wide and 5mm height with 100% infill and your current settings. Try reducing the nozzle temp as much as you can without suffering under extrusion. At 30mm/s you should be able to reduce to about 190C.

The colder you print, the shorter retractions you will need.

 

[nick-foley 5]

If you're trying to maximize quality I would go a little slower. There is evidence of some ringing on your sharp corners. 30mm or 40mm/s is going to help that.

Also lower the temperature as suggested.

Other filaments (Pure PLA instead of the PHA) may be less stringy, and can take lower temperatures. Finding US suppliers of PLA which have as good of colors as Colorfabb is tricky though...

 

[jameshs 42]

plus white is the killer material for sowing up features - colours are way more forgiving!

 

[nallath 1,118]

Try the new (quick) profiles that we've included in cura. Paul made those for us and he's pretty much the king of awesome prints.

 

[lately 0]

Thanks for all of the responses. This community is fantastic.

I've slightly lowered the temp and speed (200c and 40mm/s) and 2.5 hours into a 7 hour print things seem to be a bit cleaner. I hope to have the chance soon to run a few small calibration prints and learn a little more about the temperament of my machine.

I have had a hard time finding USA suppliers of PLA and I know ColorFabb is thought pretty highly of. I did buy some Velleman 3mm white at our local MicroCenter and within a couple of hours on the first print had a clog that took the atomic method to clear. I measured the diameter and parts were definitely as low as 2.85 but I could feel the additional resistance as it went through the bowden tube. It must just be too inconsistent to count on.

Thanks again. All the best.

 

[lately 0]

Now it looks like I spoke to soon. You can see in the images below that there is much more of the superfluous extrusions particularly around the scaffolding but in other places as well. There also are many more bumps on the sides of the prints that are facing each other where the nozzle moves from one figure to the other.

 

What I am wondering now is what the quality of the mesh that gets imported into Cura might have on the final print? These files come from a 3D scanner and have tens of thousands of triangles, sometimes many more. Because of the imprecise nature of 3D scanning is it possible that some erroneous triangles might be partly to blame for the problems? Could optimization and reducing the number of triangles in the mesh help produce better results?

I am continuing to make adjustments in speed and temp in the hope that I'll find the sweet spot.

As always thanks for the help.

 

[nallath 1,118]

The poisson surface reconstruction will, by definition produce a watertight model without overlapping faces. This is implemented in most scanner software packages, including meshlab.

If you don't like the 'orange skin' of the result, you can always apply a lambartian smoothing, as it preserves edges quite well.

 

[lately 0]

Got much better results after making the following adjustments.

- Bed leveled (still having trouble getting the first pass of the test print to stick but I'll leave that for another time)

- 1.2mm Outer Wall

- Moved my machine to a more sturdy surface (it was on a cart that sat slightly unevenly on casters and would rock during printing despite my best efforts.)

One if not all of these things definitely cleared up the 'stippling' problem I was having. As for the superfluous extrusions on the scaffolding and print edges I discovered those were the result of an 'on print' support whose first layer failed to adhere so each subsequent layer's extrusion was left hanging from the nozzle until it moved to its next location, often the next support structure, where it would be deposited.

Thanks for all the great tips, very much appreciated.