Simplify3D User Forum

Hey guys, when I start extruding an outline for the first layer I get a little excess plastic that stick up in the air, and then make for a really untidy bottom layer when the infill then sticks to it.



First thought I may have the nozzle to near the bed, so lifted it, and same issue, so lowered it, and same issue.

Also thought it could be a retraction issue, but I get no blobbing on the rest of the print?

E-steps are calibrated, layer width is calibrated, I extrude 10cm before printing, and print 2 outline skirts....this is the only real floor in my prints now.

Printing ABS onto PEI, direct drive, with a 0.6mm nozzle using S3D settings of extrusion width of 0.68mm, multiplayer of 0.90, retraction of 4mm, retraction speed 45mm/s, first layer height of 90%, first layer width 100%, and first layer speed of 40%.

Why not add a one-layer brim? That will stop the free-running extrusion at the start affecting the part....and will create extra bed adhesion.

dkightley wrote:Why not add a one-layer brim? That will stop the free-running extrusion at the start affecting the part....and will create extra bed adhesion.

Sorry, i was not clear on my post, I am already printing a brim/skirt 5mm offset from the part.

Or, do you mean a brim attached to the part? as I don't see how that wont help with the issue I have for anything but a solid bottomed part? (and most of what i print has things like holes for screws, or cutouts on them).

For example.....if I printed this, I would get those little jaggy tabs where each of the shells start printing:

Not too much plastic so much as the plastic is sticking to the nozzle and rolling up behind it. If you watch closely, the perimeter likely comes back around and falls just short of where it would connect, depending on how much plastic the nozzle drags up behind it. Try to check a couple things:

When you extrude over fee space, does the filament tend to curl in one specific direction? this can indicate that the nozzle is partially clogged or worn
Clean nozzle when you start to print each perimeter, no residual plastic/burnt crap on it
Not overextruding on the first layer, but as close to the bed as you can get reliably (this is why flatter build plates are better!)

You want that first dot to stick better to the bed than your nozzle & molten plastic in the nozzle, and this can be a bit challenging.

When you extrude over fee space, does the filament tend to curl in one specific direction? this can indicate that the nozzle is partially clogged or worn
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Not really, it flows straight down when I extrude, rather then curing to one side, and is a relatively new TwinClad XT coated nozzle that I keep clean.

try lowering your extra restart distance on the extruder tab. If the extruder is preforming a retract on the change in positions, it may be overextruding as it reprimes the extruder.

Heutinck wrote:try lowering your extra restart distance on the extruder tab. If the extruder is preforming a retract on the change in positions, it may be overextruding as it reprimes the extruder.

That you, what would a good starting point be, as its currently set to 0.00?

(Retraction distance is 4mm, retraction speed is 45mm/s, and I'm using a 0.6mm nozzle)

I would start with maybe -0,2 mm and see if that helps, and then if it does I would fine tune from there.

Heutinck wrote:I would start with maybe -0,2 mm and see if that helps, and then if it does I would fine tune from there.

Thank you, will give this a try!