Gcode mod for "extrusion multiplier" and "extra length on restart" above layer X?
 
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Gcode mod for "extrusion multiplier" and "extra length on restart" above layer X?  

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Daniel
(@daniel-11)
Eminent Member
Gcode mod for "extrusion multiplier" and "extra length on restart" above layer X?

Hey all. Is there some gcode I could add to a layer in PrusaSlicer, so that beyond said layer, I could up the "extra length on restart" and/ or "extrusion multiplier" settings? If it were possible, I think this could resolve some issues I've been having printing a part.

 

I'm printing a tall cylinder, and after is gets past some fiddly parts towards the base, I end up with gaps in the z-seam from the MK3S+ printing too fast as it goes round and round. I'd like to patch this up—once the cylindrical part of the print is reached—with some gcode that kicks in from a specified layer.

This topic was modified 2 days ago by Daniel
Posted : 24/01/2023 10:44 pm
Daniel
(@daniel-11)
Eminent Member
Topic starter answered:
RE: Gcode mod for "extrusion multiplier" and "extra length on restart" above layer X?

IMG_2353

 

Here's a video of the z-seam gap I'm dying to patch up

Posted : 24/01/2023 10:50 pm
Diem
 Diem
(@diem)
Famed Member

How thick is that vertical wall?

Cheerio,

Posted : 25/01/2023 4:10 am
Daniel
(@daniel-11)
Eminent Member
Topic starter answered:
RE: Gcode mod for "extrusion multiplier" and "extra length on restart" above layer X?

The outer wall measures 2mm

 

The inner wall measures 1mm

 

I understand this might be thin and perhaps I could make it thicker to see if that helps. 

 

My "default extrusion width" is 0.9mm, so perhaps changing this to some other value could help too.

 

Nonetheless, it's hard to fathom the reason for the z-seam gaps, as they're not consistent (photo example attached).

Posted : 25/01/2023 11:59 am
Diem
 Diem
(@diem)
Famed Member

What size nozzle are you using?  The default extrusion width for a 0.4mm nozzle 0.45mm.

As a rough guide, the minimum wall thickness for clean wall printing, is 2x the number of perimeters x the default extrusion.  Yes, you can configure better but start from there.

Cheerio,

 

Posted : 25/01/2023 2:53 pm
Daniel
(@daniel-11)
Eminent Member
Topic starter answered:
RE: Gcode mod for "extrusion multiplier" and "extra length on restart" above layer X?

Hey. I'm using a 0.8mm nozzle. I upped default extrusion width from 0.9 to 1 and it seems a little better now.

 

I'm printing a product with branding on the outside with a deadline for a video shoot, and this branding was causing some of the issues. So I decided to print a bunch of devices without any external branding to be sure I'm ready for the shoot on time. With any spare time at the end, I'll try my best to reintroduce protrusions/ branding on the external walls and get it right

Posted : 26/01/2023 12:08 pm
Diem
 Diem
(@diem)
Famed Member

For functional parts you have to calculate proportions with reference to the range of extrusion widths available to the printer - imagine building a cavity wall just one and a half bricks thick ... technically possible for a master builder but not a trivial exercise.

Hovever, perhaps you can cheat:

If it's just a prop split the part.   Print the base normally and the upper part in vase mode then assemble with glue and paint.

Cheerio,

Posted : 26/01/2023 7:29 pm
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