I found a way to adjust the front drum gap to minimum, to the point where you can't go any closer. It was possible to close it up much closer than cold position when it is hot enough to roast.
Today I had to rotate the drum by my own hand again to
aviod the distortion. It wasn't caused by any frau on the moter nor the inverter but the electro magnetic swith overreacted to trip. May be there have to be one switch for each inverter.
This time I tried roasting without any external preheaters and also turned out that the heat storage on the front panel is a REAL draw back especially when the drum gap is so narrow.
