Grifftech
Posts: 60
Joined: Tue Jun 16, 2015 12:12 pm

First Layer Width doesn't seem to do what I think it should

I am trying to increase the First Layer Width and all it seems to do is cause the distance between the lines it lays down to get further apart and doesn't seem to be increasing the extrusion at all. Any ideas?
CompoundCarl
Posts: 2005
Joined: Wed Aug 05, 2015 7:23 am

Re: First Layer Width doesn't seem to do what I think it sho

Probably means you're too far away from the bed. If the plastic isn't properly squished against the bed, then the extruded width won't be correct.
Mike01Hu
Posts: 11
Joined: Sun Nov 08, 2015 5:11 pm
Location: Lakenheath, UK

Re: First Layer Width doesn't seem to do what I think it sho

Try 80%, which will close the gap. It works for me. I think the popup dialogue is confusing as it does not increase the extrusion width by pushing out more filament.

Mike
JoeJ
Posts: 1435
Joined: Sun Feb 16, 2014 10:52 am

Re: First Layer Width doesn't seem to do what I think it sho

Mike01Hu wrote:Try 80%, which will close the gap. It works for me. I think the popup dialogue is confusing as it does not increase the extrusion width by pushing out more filament.
What doesn't push out more filament? If you set the extrusion width to 200% is ABSOLUTELY extrudes twice as much plastic. It's very easy to see by looking at the gcode files. So if it doesn't appear that way on your bed, then the nozzle must be too far away, which will obviously affect the final width on the bed.
Mike01Hu
Posts: 11
Joined: Sun Nov 08, 2015 5:11 pm
Location: Lakenheath, UK

Re: First Layer Width doesn't seem to do what I think it sho

I agree, but as Grifftech indicated this does not happen, it appears to increase the gap by the amount chosen rather than the width of the extrusion. Yet, in layer control the command works as expected. I have the same problem and this was my solution. It is not a printer firmware issue as this does not happen with other slicers.
Grifftech
Posts: 60
Joined: Tue Jun 16, 2015 12:12 pm

Re: First Layer Width doesn't seem to do what I think it sho

JoeJ wrote:
Mike01Hu wrote:Try 80%, which will close the gap. It works for me. I think the popup dialogue is confusing as it does not increase the extrusion width by pushing out more filament.
What doesn't push out more filament? If you set the extrusion width to 200% is ABSOLUTELY extrudes twice as much plastic. It's very easy to see by looking at the gcode files. So if it doesn't appear that way on your bed, then the nozzle must be too far away, which will obviously affect the final width on the bed.
My nozzle is .05mm form the bed, I use feeler gauges to verify. If I keep all settings the same and increase First Layer Width it does not bring the lines closer together but further apart. I will video it for you so you can see
JoeJ
Posts: 1435
Joined: Sun Feb 16, 2014 10:52 am

Re: First Layer Width doesn't seem to do what I think it sho

Yes, that is correct. If you set the first layer extrusion width to 200%, the lines will the twice as far apart as normal, and the printer will also be extruding twice as much plastic. Read through the gcode file. It's doing exactly what it should be. Extruding twice as much and the lines as twice as far apart.

If the lines aren't meeting up, then your bed position is wrong or you are just under-extruding in general. Plain and simple.

They have plenty of documentation that already explains these things
https://www.simplify3d.com/support/prin ... to-the-bed
https://www.simplify3d.com/support/prin ... gh-plastic
https://www.simplify3d.com/support/tuto ... rst-layer/
Fred B
Posts: 30
Joined: Thu Jan 22, 2015 7:07 pm

Re: First Layer Width doesn't seem to do what I think it sho

I think what people think the first layer width setting "should" do and what most of us want to use it for are two different things. The setting increases the width of the material coming from the nozzle but also increases the distance between paths. This means that there is little change in the amount of material being pressed into the first layer.

Most of us have used this multiplier in the past (with other slicers) to over extrude the bottom layer in order to get the part to stick to the build platform better. This also helps with cheaply made beds that are not flat across the entire surface.

The work around I have now is to set the nozzle gap to the bed at about 0.1mm and set the first layer height multiplier to get about a 0.2mm first layer. This creates the over extrusion that you want without changing the first layer pattern. So, if I have a sliced layer height of 0.1mm I set the first layer multiplier to 200% and leave the extrusion width alone. This over extrudes the first layer as intended.

I would rather have a first layer extrusion multiplier instead of the width setting but that's not a big deal once you get used to it.

Heads up, there is a bug that will sometimes close holes on the second layer when the layer height is set high (like 200%). Look for this in the preview each time. If it plugs your holes you can change the multiplier slightly and it will go away. If you don't check the added plug is reasonably easy to remove for holes 4mm and above.
billyd
Posts: 272
Joined: Mon Jan 19, 2015 12:13 pm

Re: First Layer Width doesn't seem to do what I think it sho

This is excerpted from the tip of the day compilation:

"...First Layer Settings (These are applied to where the Bed touches your model. If you have a raft, that means the First Layer Settings will apply to your raft).

First Layer Height: This % will take a % of your Primary Layer Height. If you are printing with a small Primary Layer Height like .1 mm I would recommend a First Layer Height of 250%, to get about a resulting .25 mm first layer height

If your First Layer Height is below 100%, the extrusion amount will remain the same, only the Z-will change, but if you increase above 100%, the extrusion amount will scale accordingly.

First Layer Width: the extrusion width of your first layer, you may find that your first layer sticks better with a thicker extrusion (100%+). I don't have too much experience with this, but I think 125% or 150% would be good starting points.
........."

From reading the above if you want a wider first layer you could set your first layer height to below 100%. Since the extrusion amount will be the same, and the z height reduced, you would end up with wider extrusions and more overlap since this setting will not alter path.

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