LW-PLA Temperature Calibration Problems
I just received my pre-assembled MK4 in the mail. I've been printing with an Ender 3 S1 Pro and PrusaSlicer v2.6.1 up until now. I often print with Colorfabb LW-PLA which is an active foaming filament. Colorfabb has a calibration procedure to determine the optimal hotend temperature for foaming expansion, and this process consists of setting a fixed low speed print speed (25mm/s) and a flow rate of anywhere between 50-55%. I print a lot of RC planes, and most of these designs require the printer use a 0.4mm nozzle, but they encourage calibrating the temperature such that the LW-PLA produces a single wall thickness of 0.5-0.6mm (due to extra expansion from the temperature).
On my Ender 3 S1 Pro, using PrusaSlicer v2.6.1, I printed multiple single wall test cubes with temperatures ranging from 230-250 in 5 degree increments and then measured the wall thickness with a micrometer. The results were obvious - higher temperatures led to more expansion and the walls were noticeably thicker. At 230deg I was measuring 0.42mm and at 250deg I measured 0.55mm.
I repeated the same procedure I described above using the exact same PrusaSlicer settings but with the MK4 selected as the printer. Each and every print results in a single wall thickness of 0.4mm precisely, and this was regardless of the temperature. I don't understand what is causing this. If I increase the temperature the material should foam more and produce larger wall thickness. It's as though the MK4 is dynamically adjusting flow rate or something without me knowing about it..? To reduce variables and such I disabled linear/pressure advance using the command "M900 K0" , and disabling linear/pressure advance did not change anything.
Does anyone have an idea why the MK4 would print so differently compared to the Ender 3 S1 Pro even though it was sliced with the exact same settings besides the printer selected?
RE: LW-PLA Temperature Calibration Problems
Hello jon-whit,
It seems I am running into the same issue as you. (using PolyLight 1.0 LW PLA on a MK4)
Fixed (as far a I know) settings, only changing the temperature, no difference in wall thickness...
Were you able to find a solution?
RE:
Any luck so far?
I tried Cura but same results. I then found these projects on printables.com, the cubes printed great.
Polylight LW-PLA foaming expansion test by extrusion multiplier
Polylight LW-PLA foamingexpansion test by temperature
I am now trying the settings on my own print, will let you know how it goes.
RE: LW-PLA Temperature Calibration Problems
Would like to know the results. Looking to purchase a MK4 for printing 3dprintlab planes. But if the MK4 is not capable, I will have to look at the MK3 route.
RE: LW-PLA Temperature Calibration Problems
Any resolution to this problem? I have the same issue, only worse. As I increase the print temp, the wall thickness actually decreases.
No idea what's going on.
RE: LW-PLA Temperature Calibration Problems
Just in case anyone else is having this issue.... this is what worked for me.
I think the main problem is that I was printing test cubes in vase mode. Once I stopped using vase mode, the filament behaved as expected, expanding with higher temps.
Other things I did where:
Make sure "max volumetric speed" is set to 0 (print settings>speed)
Set "max volumetric speed" to 0 in filament settings>advanced
set "slow down if layer print time is below" to 3 (filament>cooling)
For newbs like me that didn't already know, I also found it helpful to check the print once sliced in prusaslicer using the legend info panel in the upper left. You can check speed and volumetric flow rate to be sure the printer is changing temperature only when checking expansion rates of the filament.
Hope that helps.