Can anyone help. I have the settings dialled in pretty well in terms of bottom layer and walls but the top of the print is awful. Colorfabb XT Yellow. 245deg hot end 85deg bed 1st layer. 75 onwards. 45mm/s print. 0 fan 1st layer. 30% onwards. 4 top 4 bottom 4 perimeters. 0.18mm layer height
Great photo but unfortunately the bit that we want to see - the top - is out of focus! Any chance of another?
I have edited the original post. Hopefully that ones better! It'll teach me for trying to do it fast!!
Your fan speed is too low, should be at least 60% for top layers. start with 0% and increase with 5% increments per layer Top and bottom layers should at least 1.2 mm so add some more layers. Also infill should be at least 20 %
Following your advice I have used the 2 layer 5% increases but at 60% I get thermal runaway issues. This is when I am printing the dual hot end part which is a pretty big flat area so this may be my issue. Any ideas? I am thinking about adding some extra code in so when the top layers are printing the fan speed goes up to 60% and then bring them back down, but this should be easier to solve. Think, think.....
Something that is interesting to do: if you peer into the electronics compartment when printing you can see a little LED for the extruder heater. (On my BB pro it's called HE0... You can figure out what it is by playing with the temperature controls.) It may be off, may be flashing, may be full on. If it's full on all the time (like it is when the BB is heating up) then that likely means the BB is working flatout to keep the nozzle at temperature (having to deal with the cold air and plastic arriving all the time). Which means it probably can't handle any more fan speed. If, on the other hand, it's blinking on and off, well it probably could take a bit more fan!
