perimeter problem with new nozzle

I'm having a hard time calibrating my new nozzle. I built a prusa with a budaschnozzle. The budaschnozzle came with a 0.5mm nozzle and that was fine, but I wanted more resolution so I bought the 0.25mm nozzle. I'm using slic3r for the most part and it worked great with the 0.5mm nozzle. I've been trying to print a single wall yoda just to tune in the new nozzle. I know it won't print the entire yoda correctly but I'm having problems in areas that I shouldn't have problems with.

It seems that my biggest problem starts when a new layer starts. After the nozzle starts to flow the print looks great, but for the for few mm after the nozzle starts the print fails. It almost seems like I'm getting inconsistant flow rates at the beginning of the layer.

Things I've tried:
Increasing the temperature, I'm printing with ABS at 245C
Increasing the amount of material by playing with the extrusion multiplier.
Slowing down
Speeding up

Any suggestions as to what causes these problems would be great. I've put the images on flickr so you can see a higher resolution version.

Thanks Guys!



Initial calibration with default slic3r settings.
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Increased temperature.
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Increased extrusion by 5%
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What is the layer thickness? The extruded width might be too narrow so that there's not enough overlap between the layers. If you decrease the layer thickness to 0.1 or 0.05 mm, slicer would automatically increase the extruded width.

I'm currently printing with a layer thickness of 0.15mm. I'll decrease it to 0.1mm, and let you know how it goes.

I started a print but it was pretty clear it was going to fail after a few layers.

Failure at corners
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Failure at start of new layer
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Here's the settings I'm using in slic3r
Layer height: 0.1
First Layer Ratio: 2

Perimeters: 1
Solid Layers: 2

Retraction Length: 1
Lift Z: 0
Speed: 90
Extra length on restart: 0.01

I've printed a nice Yoda recently. I was using :

- 0.15 layer height
- 3 perimeters (more lateral support for overhangs).
- 4 Solid layers (at that layer height it helps)
- 10% infill only (it's actually only so that the z movements is made inside the shape, to avoid blobs on the surface).
- No retraction (the only place it is needed is between the ears and head, easy to clean, and enabling it would generate blobs on the surface).
- A fan blowing on the part !

As said before with a 0.25 nozzle you're better not use layer height bigger than 1/6 mm (which give a WoT ratio of 1.5). So 0.15 should still work.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks DeuxVis,

I tried printing again with two perimeters just to see if the problem went away, and it did. I guess that 0.25 nozzle just can't do one perimeter, which is fine.

I stopped the print pretty early and printed again with your settings. Seems to work pretty great. I don't have a fan so that might be why I have problems with the low angles on the ears and the initial part of the chin. I think I have to use a small amount of retract and a tiny bit of extra extrusion on start (0.02) since I have the budaschnozzle. I think the budaschnozzle has some oozing problems since its so long.

Thanks again!