Probably the most significant change I made for PolyLite PLA on the Workhorse was to raise the print temp to 230°C
I use:
Print temp: 230°C (225°C is ok for "initial printing temp and final printing temp).
Bed temp: 55°C or 50°C … but use the same temp for initial layer and all layers. Normally it may want to print initial layer at one temp, then the remaining layers at a slightly cooler temp. I have … a few times … encountered situations where the part broke free of the bed when doing this. When I use the same temp for all layers I no longer have the issue. Apparently allowing the build plate to cool off 5°C was just enough contraction on the filament to weaken the adhesion. These days I flip the bed to the glass side and use MagiGoo.
Retraction distance: 1mm
Maximum Retraction Count: 5
Minimum Extrusion Distance Window: 2mm
These settings avoid having the same short segment of filament roll through the hobb gear over and over … chewing up the filament. This is only an issue on jobs that have lots of retractions in a very tight area. It causes Cura to skip excess retractions until it gets on to some fresh filament that isn’t chewed up.
Print speed: 40
Infill speed: 40
Wall speed: 35mm
Initial layer speed: 15mm
In the Travel section I sometimes enabled “Combing Mode”. This causes the nozzle to travel along the part instead of moving directly to the next area that needs extruding. It increases the travel time, but when using filaments that “ooze” and may result in stringing, the filament oozes onto the inner walls or infill so that you don’t have stringing. This usually is not necessary with PollyLite PLA as it wont string much (if any) at 230°C with 1mm retraction.
In the Travel section I normally leave “Z Hop When Retracted” off. But when I do turn it on, I usually set it to “Z Hop Only Over Printed Parts”. This is because sometimes Z-hopping leaves a tiny nub where it pulls up (like a tiny “Hershey’s Kiss”).
Other things:
Linear Advance: The printer runs Marlin 2.x firmware and Linear Advance is already enabled… but the “K” value is set to 0.0 (effectively this means the linear advance wont make any modification to the flow rate).
As the print head changes speed, the extruder also changes speed. But since filament is in a state of “goo” when melted, there’s a little bit of a delay. Linear Advance allows the Marlin firmware to respond by altering extrusion speeds in advance of acceleration changes so that you get smooth extrusion.
When I ran the Linear Advance test on my Workhorse using PolyLite PLA, I found the best setting on my particular printer was K=0.13. When I ran the same test on my Pro I found the best setting was K=0.12 (so very close).
You can set the K value by (using the control panel on the printer itself… not in Cura) navigate to “Configuration” -> “Advanced Settings” -> “Filament” -> “Advanced K” and then dial in the value you want (e.g. I set it to 0.13). After doing this, I think there’s another menu where you have to ‘Save’ the setting … otherwise it will lose the setting when you power off the printer.