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Hello, I've had my Rostock Max v2 for just over a month now and have not yet run into this issue...

[img]http://i.imgur.com/S51ar0Dl.jpg[/img]
[img]http://i.imgur.com/AP19yaul.jpg[/img]

As you can see from the photos, the top layer on these calibration cubes is not printing properly.

Layer Height: 0.1mm
Heatbed: 90C
Extruder: 223C
Filament: ABS
Slicer: MatterControl

All hardware is that of the stock machine.

The common cause of this is too few solid layers, but I have successfully printed at 0.2-0.3mm layer height with 0.8mm of solid top layers. I've experimented with speeds as well. The cube in the second image has an infill speed of 50mm/sec. Various amounts of infill have also been tested and though it may prevent holes in some cases, warping still occurs. I ended up printing over a dozen of these calibration boxes, changing one setting at a time, to no avail . What I've deduced is that when the nozzle travels over the previous solid layer, it melts it completely: allowing it to warp. This doesn't occur with thicker layers as they can handle the heat transfer better. So my question is, how can I regulate this? Is there some type of way to decrease the temperature when printing those top layers (I have attempted the minimum print time per layer but the nozzle melts the plastic anyways)?

Thanks,
Matt

I usually just keep piling on the top solid layers the finer my layer resolution until it goes away. I've had the same thing happen to me.

Agisis wrote:I usually just keep piling on the top solid layers the finer my layer resolution until it goes away. I've had the same thing happen to me.

Thanks for the reply!

Care to share settings that have worked for you? I've been trying different amounts of solid layers with no success. The model in the attached image had 3mm (30 layers) of solid covering. It might have been difficult to tell from the images, but that upper layer is warping outwards as if there was bubble underneath. Could it be that I'm over extruding?

[img]http://i.imgur.com/m1F7ljx.jpg[/img]

You need more infill, your settings aren't allowing you to bridge properly so its just bunching up as it hits the infill, then it kicks up, eventually there is enough goop there to hold a layer, then it bulges. My go-to infill is 30%

Alright, I'm printing with these settings now, will report on how it goes. The last print was done at 25% infill so hopefully it will make a difference. Also, you are spot on with the bunching issue, I cut the model in half and this is what the underside of the top layer looks like:
[img]http://i.imgur.com/8b3Eiok.jpg[/img]

I see many people on these forums don't use mattercontrol, are there reasons for that past personal preference?

Okay, here's the cube with 30% infill @ 3mm of solid top layers. There appears to be a bulge in the same place, but it's much less apparent. Upping the infill is okay for smaller prints, but I'm worried about how that may induce warping on larger ones.

[img]http://i.imgur.com/0T8cPuel.jpg[/img]

I'm still considering the possibility that I'm extruding the incorrect amount of filament. I recently moved my cold-end to the outside of the printer in preparation of an enclosure, so there is about 30cm extra bowden line the filament is being pushed through.

These doodads appeal to tinkerers. People try things and like different things.

In my case, MC wouldn't even open before crashing. I haven't tried it since the Win 10 upgrade.

It doesn't hurt that the idea of a lightweight host and a standalone slicing program appeals to me.

If your printing at 0.1mm with a 0.5mm nozzle, your at the very edge of what's practical, and you'll find that filament stretched that thin will not bridge worth a damn, to the point that you can't get away with sparse infill if the top layer is any significant area and flat. When the plastic comes out of the nozzle it's stretched rather than squirted and if it's stretched too much it snaps.

There are several ways to get around this,

Print with more infill you might need as much as 50%, this reduces the distance the filament bridges.
Use a smaller nozzle, a 0.35mm nozzle will have no issues at 0.1mm, but it also introduces other issues.
Set the extrusion width to be wider, say 0.8mm, this works to a point, it reduces the overall stretching that goes on.
Depending on the plastic, printing hotter might help, this tends to work better with PLA, but it introduces other problems that then have to be addressed.

Huh, interesting. I thought the stock hotend had a 0.4mm nozzle. I think this may be the source of many other problems I've been having...

I guess I'm off to buy a smaller nozzle

I've tried overextruding on the top layers, but that caused it's own slew of errors, extrusion width may work differently though. I think ramping up the infill may be the best solution since, as displayed in an image I posted earlier, the underside of the top layers had tons of issues bridging.
Thanks for those tips, I'll be trying them all today and post back what worked if anyone has this problem later.

EDIT:
I'm wondering if I should bother getting a new nozzle for the stock hotend or if I should upgrade to a new hotend all together. I've heard E3D J-heads are pretty nice.

An E3D isn't a J-Head. The ONLY "true" J-Head is available here: http://www.hot-ends.com

g.