Perfecting Dual Extrusion Settings and Scripts (S3D)
Posted by SJMaybury
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Perfecting Dual Extrusion Settings and Scripts (S3D) August 05, 2017 12:14PM |
Hi all,
I’ve been happily printing single nozzle with my own-design printer for over a year now. I decided to upgrade to dual extrusion and having got the nozzles aligned in X, Y and Z perfectly decided to do my first big print.
Bit of background: my printer is now running a hybrid Direct-Bowden pair, slices via Simplify-3D and I’ve printed with both the Direct and Bowden individually without a problem, my standard retraction distances are fine.
My big print (the Voronoi Rocktopi) was printed with a retraction script that lowered the temperature of the unused nozzle from 200°C to 180°C and raised the new temp to suit. This, obviously, added A LOT of time to the print. I also still had stringing and blobbing on the print and prime pillar.
So, following that and not wanting to increase my print time by 20% while heating and cooling nozzles, I set about trying to perfect my “nozzle change” retraction distance. Too low (<10mm) and it would ooze badly. Not high enough (>10mm, <20mm) and it would skip when trying to extrude again. I discovered this was because of a plug forming on the end of the filament as it moved somewhat out of the hot zone and cooled.
I figured move it up completely out of the hot zone (I’m using genuine E3D full metal so planned to move it to the top of that) by about 20mm and it could cool without forming into a plug. I ran some tests on that, retracting it, waiting 3 minutes and extruding it and all seemed fine. Tried it in a test print and it skipped anyway.
So, should I retract further? Pull the filament completely up into the PTFE above the full metal throat? Should I be only retracting it by about 2-5mm and somehow cooling it enough not to ooze? Is it possible to cool it without waiting a whole minute before the print resumes? Can I warm up a nozzle BEFORE it’s needed somehow? Should I be using a higher retraction speed to prevent stretching the filament or a lower one because we want that taper to aide the restart?
Any advice here would be greatly appreciated, thank you in advance
I’ve been happily printing single nozzle with my own-design printer for over a year now. I decided to upgrade to dual extrusion and having got the nozzles aligned in X, Y and Z perfectly decided to do my first big print.
Bit of background: my printer is now running a hybrid Direct-Bowden pair, slices via Simplify-3D and I’ve printed with both the Direct and Bowden individually without a problem, my standard retraction distances are fine.
My big print (the Voronoi Rocktopi) was printed with a retraction script that lowered the temperature of the unused nozzle from 200°C to 180°C and raised the new temp to suit. This, obviously, added A LOT of time to the print. I also still had stringing and blobbing on the print and prime pillar.
So, following that and not wanting to increase my print time by 20% while heating and cooling nozzles, I set about trying to perfect my “nozzle change” retraction distance. Too low (<10mm) and it would ooze badly. Not high enough (>10mm, <20mm) and it would skip when trying to extrude again. I discovered this was because of a plug forming on the end of the filament as it moved somewhat out of the hot zone and cooled.
I figured move it up completely out of the hot zone (I’m using genuine E3D full metal so planned to move it to the top of that) by about 20mm and it could cool without forming into a plug. I ran some tests on that, retracting it, waiting 3 minutes and extruding it and all seemed fine. Tried it in a test print and it skipped anyway.
So, should I retract further? Pull the filament completely up into the PTFE above the full metal throat? Should I be only retracting it by about 2-5mm and somehow cooling it enough not to ooze? Is it possible to cool it without waiting a whole minute before the print resumes? Can I warm up a nozzle BEFORE it’s needed somehow? Should I be using a higher retraction speed to prevent stretching the filament or a lower one because we want that taper to aide the restart?
Any advice here would be greatly appreciated, thank you in advance
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