Top surface didn't fully closed

[lan 0]

Hi,

I have been trying to print the squinty head model (http://www.flickr.com/photos/98728747@N03/9263653778/lightbox/). The setting I used were:

Layer height : 0.1

Shell thickness : 0.8

Top thickness : 1.2

Fill density : 0

Is there any other setting that I should change?

Thanks in advance for your advise guys!

 

[illuminarti 18]

What temp and speed are you printing at?

What program are you slicing it with? I recommend using the latest Cura. I get pretty good results printing hollow models like these, even with zero infill, although I haven't tried this one (yet).

That said, the top of objects like this is always going to be tough, because there's a very gentle slope, so you can easily end up printing over the top of nothing. You need to make sure that there is good overlap between the layers. Going to a thinner layer height might help (I like 0.06 for these sorts of things) ... or adding a third loop (going to 1.2mm shell thickness).

 

[gr5 2,189]

Make sure the fan is on and make sure it is taking at least 5 seconds per layer. If you don't do both of those then you will get exactly what you see here (although I think illuminarti is right and it's printing over air). For example the "minimal layer time" should be at 7 seconds and more importantly, "minimum speed" should be 0 (under expert/cool).

 

[owen 19]

Or you could give it 10% fill

 

[illuminarti 18]

As a reference, I finally tried printing this, and I'm really delighted with the results. It's a fairly easy model to print, as there are no steep overhangs - the print didn't need any external clean up.

 

I printed it 10cm high, with zero infill, 0.06mm layers, 1mm top thickness, and 1.3mm skin (2 passes of my 0.65mm nozzle) at about 135mm/s (I set it to 150mm/s, with a 7mm min layer time - which slowed it down to about 76mm/s. I then gradually cranked the speed up to 175% in the Ulticontroller - so the overall requested speed was about 135mm/s). I forgot to check the total print time, but it was about 3.5hrs, I think.

 

The fan was on for the whole print, and the top closed up absolutely fine for me. As George mentioned, I think the critical thing is to make sure that the minimum layer time is long enough. 4 seconds proved to be more than long enough for me here, with 0.06mm layers, but will need to be increased for thicker layers I imagine.