from 0,4 to 0,8 nozzle ABS, from paradise to hell

Hi all,
after many tries of calibrating in Sli3er I am really tired of 0,8 nozzle. I always used 0,4 with no problem. I am printing with ABS mostly.
with 0,8 nozzle I use 1mm extrusion width and 0,4mm for layer high. Temperatures from 240 - 260°C for nozzle, 100°C for heat bed. I use bowden so I have retraction around 16-20mm.
Printing speed around 40mm/s.

I attach some photos. Big problem I had with 2mm walls where it looks like overextruded, there are also some holes and blobs on another object I printed.

Can anyone share some Sli3er configuration for 0,8 nozzle which work with ABS ?

thanks

I feel your pain. I, too, have struggled to get decent prints out of large nozzles with a volcano heater block. I have never been able to come up with a "formula" for settings that work with everything. You have to tune the settings for each and every print. Ugh!

Cura has a plugin called scalable extra prime (use the toolbox menu to access it) that helps correct gaps at the start of extrusion after a travel move.

With big nozzles, you need a high powered heater, big heater block, and you have to print slow. The thing you have to keep in mind is that doubling nozzle diameter increases volume by 4x. Printing at 30 mm/sec with a 0.8 mm nozzle is like printing at 120 mm/sec with a 0.4 mm nozzle.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

... with a 0.8mm bore the filament is more sensitive to temperature and printing speed, what's influencing the viscosity and "swell" after nozzle exit.

This are some images from my first tests with a 0.8mm nozzle maybe ten years ago:

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Some earlier slic3r version weren't able to deal with changing the nozzle diameter in the setup. You had to start a new printer profile.
They seem to have found the bug ( at least in the Prusa Edition branch ) but it wouldn't hurt to start from a new profile and see if it works better.

Some of the features seem to be taylor made for 0.4mm nozzles. I'd try to use 0.8mm extrusion width and 0.5mm layer height.

Hi,
yes, I tried to use lower speed also different layer hights, but still the same. Maybe it is by the extruder, I use V6, I do not have experience
with Volcano. This Yellow print of gears looks good in my opinion, could be better but it is much better than main. Machine has
I think larger heater block than V6.

This yellow print is it PLA or ABS ? Because that is big difference then...

... this was on the heated bed coated with PET, so should be ABS ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Cool,
so maybe I should try Volcano then.

thanks

you do need something like a volcano or slow down lots

Also larger mass keep heat longer, so more print cooling is required or increase inter layer dwell time.

Even if I slow down the result is bad. Main factor of it is that V6 nozzle is blobing and plastic is released even after long retraction.
What I expect from Volcano is to be able make ABS more liquid and to be able suck it back more easily to prevent these blobing.
I do not know if Volcano helps that, I hope so. If you have some experience Ill be glad to read it.