Drizzle - my new favorite SF setting

Hey all,

As I'm sure many of you have experienced - there are quite a few tabs on SF that go unused. I've been trying several different things to reduce the blobbing at the end of the perimeters where the head pauses for a moment before proceeding to fill.

Clip is supposed to end the perimeter loop early. I haven't noticed though that it does anything useful.

Oozebane is supposed to slow down and extrude less towards the end of a line to reduce this issue. Instead it seems to make it worse by slowing down and blobbing everywhere. It's possible I just don't have the settings right to take advantage, but the motion changes in general are not what I wanted.

Drizzle though - drizzle is my new friend. Drizzle does what I thought oozebane would do - it slows down the *extrusion rate* as it finishes a print move. And it doesn't screw with the extrusion rate when it's not stopping (ie. as it approaches a corner where it's going to keep printing) like oozebane sometimes would. In short - it works.

Here's a test couple test prints I did back to back with and without Drizzle - no other settings changed.



The one issue now though is it acts a bit like retraction without a restart - so when it starts to print again, the extrusion is a bit light and there's a bit of a void. (I thought splodge was supposed to overcome this issue, but it just makes an awful mess). Anyway - I'm hoping I can overcome the voids by tuning the settings a bit more, but overall I really do like the affect and hope to use it to finally clean up all my Z-axis zippers.

Thx for trying out the new functions... Its interesting to see how the different settings work... I have also tryed oozebane, but I couldn't get it going with my stepper based extruder... Could it be that oozebane was for DC motor based extruders and doesn't work right for stepper based? Maybe someone with a working oozebane setup can help us out?

Thx...

You mean "Dwindle", right ?

I tried that yesterday, with the default module settings (did not change 'em as I have no idea what they mean).

For me, it does reduce stringing, but not as much as retraction can. And the cost is an extended print time - along with an unusual sound as the print head spends a lot of time decelerating.

I saw no improvement to the "corner pillar blobling" problem when using it, despite of what you show us - maybe because I was using a fan an thin layers (0.15).

It probably can be used together with retraction, did not test that yet.


Did you change the defaults settings of the Dwindle module for your tests ?

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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.

Wow - I'm not getting *that* old yet am I? Uh...yea - Dwindle, not Drizzle. /facepalm

I changed the following two settings:
End Rate Multiplier : 0.25
Pent Up Volume : 0.5

I think it's still not quite there - I might try these next:
End Rate Multiplier : 0.2
Pent Up Volume : 0.75

I also tried enabling "extruder advance" in Marlin, which is also meant to address the problem of corner blobbing & starting thin. I started with ( 0.02 ) advance constant. I've seen a few machines set at 0.3 which is more than an order of magnitude more so I wanted to try this first, but I'm not noticing any significant change @ 0.02 so 0.3 is next and then 0.5 or 1.0 unless I can see an improvement.

I think this could be better addressed by the firmware extruder advance, but Dwindle is better than nothing for now. Also - those cubes are at 0.25mm layer height @ 75mm/s, ABS.

Edited 1 time(s). Last edit at 04/17/2012 11:22AM by JazzyMT.

Oh and yes - Dwindle doesn't have any affect on corner blobbing in general because they're not the *end* of a print line, just a change in direction. I agree that retraction should cure most of the Z-step blob (which I have on), but it's like it doesn't retract soon enough and it hesitates at the end for a moment which is enough time to make an extra fat blob. I never get strings, but I do get blobs - very annoying.

I have found that using filet (which I changed to "Arc Segment", corner feed ratio : 0.7, Filet Radius over Perimeter Width : 1.5) really does help a lot with corners - and reduces vibration a lot too. Unfortunately it doesn't seem to work on very complex models (fails carve), so you can't always use it.