Next test finished: Speed vs. Overhangs
Cooling was set to 10% part fan, 20% aus fan.
I created a small model with sharp and rounded overhangs at 40%, 70% (-> ranges that orca / bambu allows to reduce speed for) 45°, 55° and 65°. I printed that at 30, 50, 100, 180 and 300 mm/s.
IEMAI printed perfect overhangs up to 45° at 300mm/s. At 55°C there is slight curling at the top layer, which gets a little bit better the slower the speed. But it doesn’t disappear completely even at 30mm/s.I will repeat with more fan. The 65° was never good. at 30mm/s it keeps up ok the first few mm but at 5mm is also quite distorted.
Sunlu has practically the same results up to 45° only at 300mm/s I can see the slightest curling. At 55° I wouldn’t print it faster than 100mm/s. 65° is very similar to IEMAI again.
I didn’t test the Bambu PETG because I will not use it anymore and sell the remaining sealed rolls.
Next test will be the influence of fans and layer times. I really have the feeling that not speed but time for cooling is the most critical factor for good prints.