Slic3R Missing Layers

Hi Guys, I know this is not really Ormerod specific but I am sure someone knows the answer to this.

I am trying to print a couple of trim pot shafts that have a thin 0.5mm cross on the top of a 4mm cylinder. The stl looks fine in slicer but it doesn't output any gcode for the cross part. It just ouputs z moves...

G1 Z7.200 F3000.000
G1 Z7.440 F3000.000
G1 Z7.680 F3000.000
G1 Z7.920 F3000.000
G1 Z8.160 F3000.000
G1 Z8.400 F3000.000
G1 Z8.640 F3000.000
G1 Z8.880 F3000.000
G1 Z9.120 F3000.000
G1 Z9.360 F3000.000
G1 Z9.600 F3000.000
G1 Z9.840 F3000.000
G1 Z10.080 F3000.000

I am sure it's probably a simple setting so any suggestions welcome.

Regards,

Les

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Pointy's Things
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Which version of slic3r are you using, and what do you have the extrusion width set to?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
Which version of slic3r are you using, and what do you have the extrusion width set to?

I am using 1.1.4 and I have tried 0.5 and 0.3mm

Regards,

Les

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Pointy's Things
Pointy's Blog

Les,
try reverting back to slic3r-1.1.3, I have been having problems with 1.1.4 so it might help your issue

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slic3r-1.3.0, Simplify3D 4.1.2, Cura-4.4.1

Quote
appjaws1
Les,
try reverting back to slic3r-1.1.3, I have been having problems with 1.1.4 so it might help your issue

Thanks for the suggestion but I think I was on 1.1.3 and then tried upgrading to 1.1.4. I just tried 1.01 and the gcode looks okay. I will know for sure when I try and print it tomorrow.

Regards,

Les

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Pointy's Things
Pointy's Blog

Using Slic3r 1.01 they did finally print, although they came out terrible. The cross on top was more of a blob. If anyone else fancies trying to print these and is successful, please let me know what settings you are using.(They only take about 6 minutes to print)

Regards,

Les

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Pointy's Things
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Les, do you have an openscad model of that trimmer shaft?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Sorry DC, I don't use openscad, but it very simple. It's a 4mm cylinder 7mm high, centred on top is a 2mm x 0.5mm cross 3mm high.

Regards,

Les

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Pointy's Things
Pointy's Blog

I recreated that model in OpenScad, sliced it with slic3r 1.1.1 and got the same results, i.e. z-movement only. Then I increased the width of the cross to 0.51mm. This time I did get extrusion:

G1 Z9.360 F12000.000
G1 X95.000 Y101.000 F12000.000
G1 E4.00000 F2700.000
G1 X95.000 Y100.000 E0.04989 F840.000
G1 X96.000 Y100.000 E0.04989
G1 F2700.000 E-4.00000
G1 X105.000 Y101.000 F12000.000
G1 E4.00000 F2700.000
G1 X105.000 Y100.000 E0.04989 F840.000
G1 X106.000 Y100.000 E0.04989
G1 F2700.000 E-4.00000
G1 Z9.600 F12000.000

So this version of slic3r seems to ignore the cross unless it is thicker than the nozzle width. I had previously tried reducing all the extrusion width settings in slic3r to 0.499mm, but that didn't work. Maybe I should have told slic3r that the nozzle was 0.499mm instead.

It appears to be trying to print the cross as two right angles. But it made a terrible job of it. I think the issue is that retracting the filament, moving, extending the filament, then extruding a tiny amount of filament just doesn't work - the extrusion can't start that fast.

It occurred to me that if you were to use a 0.3mm nozzle and increase the cross to be 0.6mm wide, then it could print the cross in one continuous movement. To test this theory, I scaled up the design to produce a 1mm x 3.5mm cross. This time I got a better result:



I shortened the cylinder to reduce print time and added a brim to give better adhesion to the glass.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks for testing dc.

I could have sworn I tried setting the nozzle to 0.3mm, but anyway it looks like it's just too smaller detail to try and print. Maybe with a 0.3mm nozzle it would be better so I might get one of the hotend kits with the smaller nozzle to try.

Regards,

Les

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Pointy's Things
Pointy's Blog

I really like Slic3r, but it does do some very strange things sometimes.
When I was test printing the Big Blue, at one time it put a complete floor through the whole of the fan/duct, and made it totaly useless.
That was triggered by a screw hole that was at that height, but no where near the place it put the floor in.
I shortend the screw hole by 0.5mm and it did it fine after that.

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Please send me a PM if you have suggestions, or problems with Big Blue 360.
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Working Link to Big Blue 360 Complete

You might get better results by including a sacrificial column or loading 4 of those parts so the head has to move away from each part between layers. Tall thin objects tend to get too hot if printed alone. Still, I think the detail on that part is too small to print satisfactorily with a Bowden extruder - the filament cannot be extruded at exactly the right place because of extruder lag. You could perhaps try extending the cross to each side of the print and cutting/filing away the excess afterwards (see attachments)

Dave
(#106)

Thanks for the suggestions Dave, I did try slowing printing speed right down to 10mm/s and travel to 50mm/s but it made no difference, I knew I wouldn't be able to print one on it's own, which is why I added the second to allow some cooling time. I might try making it a single 2mm wall on top like a flat blade screwdriver, which would be easy to fettle. I have also just ordered the 0.3mm hotend kit to play with.

Going back to Slic3r, it's strange that it included the 0.5mm supports I added on this piece.

Regards,

Les

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