Severe PC-Blend Warping on Massive Part (CoreOne) – Hardware Limit or Slicer Issue?
Hi everyone,
I’m currently printing a rather massive filter cassette on my Prusa CoreOne using unfilled Prusament PC-Blend. Despite a lot of preparation and a solid first layer, the part warped so aggressively during the print/cooling phase that it formed a severe "banana shape" at the bottom and even deformed an internal hole meant for a heat-set insert due to internal shrinkage stresses.
Before I surrender and switch to PC-Blend CF, I wanted to get a sanity check from the experienced PC-Blend users here to see if there is any slicer trick left to save this.
The Setup & Preparation:
Printer: Prusa CoreOne (closed doors/lid, exhaust fan blocked to maximize chamber temp).
Filament: Prusament PC-Blend (unfilled). Dried for 7 hours at 65 °C in a SpacePi filament dryer and printed directly out of the active dryer.
Build Plate: Satin Sheet with a thin, dried layer of PVP glue stick (UHU).
Temperatures: * Nozzle: 275 °C
Bed: 115 °C
Chamber: Maintained a constant 55 °C after the first layer (thanks to heat soaking and hotend thermal mass).
Cooling (Post-Print): I attempted an "annealing/slow cool-down" after the print finished by leaving the bed at 75 °C for 30 minutes before letting it cool completely.
Slicer Settings (PrusaSlicer):
Brim: 10 mm
Infill: 15% Gyroid (to minimize directional stress)
Part Cooling Fan: 0%
Chamber Fan: Set to auto (barely engaged).
Perimeters: Arachne engine active.
The Symptoms: The first layer adhesion was actually fantastic. The part stuck to the glue/sheet perfectly at the beginning. However, the massive thermal mass of the thick walls and infill seemed to overpower the adhesion over time, lifting the corners and warping the internal geometry. I suspect the part mainly warped during the cool-down phase, because the top layer looks great and is quite flat.
My Questions:
Is a massive part like this simply hitting the physical limits of unfilled PC-Blend on a passively heated printer (even at 55 °C chamber temp)?
Would switching to PC-Blend CF completely eliminate this specific issue due to the carbon fibers counteracting the shrinkage?
Are there any hidden slicer tricks (e.g., asymmetric infill angles, specific extrusion width tweaks for the first layers) to relieve internal stresses before giving up on the unfilled material?
I have attached pictures of the warped bottom and the squeezed heat-insert hole. Any advice is highly appreciated!
