Rough Texture on Lower Rounded-Edges

[AJDouglas 0]

Having some issues with rough rounded edges on 3DBenchy using Ultimaker 3. I am using Ultimaker PLA and the default cura settings for the material at 0.1mm. Any thoughts / ideas to try would be greatly appreciated.

[AJDouglas 0]

Update: I tried slowing the print down, especially on earlier layers, and the problem isn't as severe. However, now all lower portions of the print have a rougher texture that corrects about halfway up. Not sure where to go from here.

[krys 206]

Hi there,

Underside curves can be tricky. Sometimes/often it is the radiated heat from the headed bed itself that causes the roughness. That is why it goes away higher up.

In the past, I have worked around the issue by printing on a cold bed with blue painters tape (wiped with alcohol), and/or printing with thicker layer heights (0.15 or 0.2). But these are very old school techniques and not really a solution that shows off your printer's awesomeness. I know the UM2/3 can do much better.

Maybe try lowering the bed heat after the first layer is put down? Maybe try that in combination with slower. Generally slower = better prints. Also maybe try lowering the nozzle temperature by 5-10 degrees after the first layer. Most PLAs can tolerate that.

I suppose raft might technically help too, but that feels like another ugly hack to me.

Beyond that I never really solved it though. I just got good enough and moved on. But I am positive others on this forum know how to address it properly.

Anyway, I hope this helps and maybe gives you some ideas to play with.

Good luck!

[AJDouglas 0]

Thanks you, Krys, this was very helpful

[geert_2 432]

I also have this on overhangs. It seems to come from edges of overhangs curling upwards, and then being pushed down irregularly when the next layer is printed.

Printing cooler helps, but does not totally cure it. What also helps, is placing a fan in front of the printer, or blowing with a gentle stream of compressed air on the affected parts (especially for very small parts, not practical for large parts).

Sometimes you can go down to 190°C at default speed of 50mm/s for PLA, depending on PLA brand, color, state of the rest of your machine (eg. teflon coupler), and the friction or unwinding resistance in the spool.

Printing slower generally improves model accuracy, but I do not know if it has an effect on overhangs, I haven't tried that.

[Torgeir 133]

Hi Folks,

Had the same thing happen when I printed the Benchy boat with my UM2 ..

Only thing that's removed all of this was to turn off the heat bed and using glue. Try this and you'll have a premium print!

It's the heat from both, -the bed and the nozzle. This often occur when printing detailed objects with overhang close to the bed bottom.

Thanks.

Torgeir.