Any thoughts on what I can do to improve the top layers. Got some improvement with variable layer height (adaptive quality/speed 0.5). X1-Carbon, ASM, Bambu PETG-CF, Strength @BBL X1C 0.6 nozzle, tree support, dried filament 8 hours.
I have not tested it but wonder if this happens because there aren’t enough layers on the top surface to bridge the infill fully. Maybe add a layer or two to see if it helps. It seems like each successive layer irons the prior one and after a couple or three, it’s fairly smooth.
Just my 2 cents I think your printer is slowing down to give more time between layers causing problems on the surface. change setting in slicer to not slow down for layer cooling. I know it is in the slicer but I am at work and don’t have the software on my computer so I can’t screen shot what needs changing but if you are in BL studio and search settings for layer cooling you should find what I am talking about and try that.
That’s what the Min Print Speed parameter is for. Leave the slow down turned on but limit how slow it can go instead.
An update. First, thanks for the input. I am unsure of the exact solution since I changed a few variables at once. The top layers increased to 6, increasing infill percent and speeding up the minimum print speed in the filament cooling dialog. Oddly enough, this minimum print speed was already increased in the generic PTGE profile vs the Bambu PTEG-CF profile. As you can tell, I also switched the filament to Hatchbox PETG. This is a lamp housing, so it saves a painting step. The last item was a design change. I rounded the inside edges, While this was done primarily for radiometric reasons, it did have the effect of providing structural strength and the need for less tree support at the apex.
