about a week and a half ago I was in the shop and prepped my first roast of the day of our red rooster espresso, everything ran as normal, beans were lofting nicely, then all hell broke loose, the roaster starting vibrating like mad, tremors went through the floor throughout the rest of the shop. i killed the roast.

upon inspection it turned out that one of the impeller fan blades had cracked right where it meets the shaft and that was creating the rediculous amount of vibration. we pulled the part and dropped it off at our welder to be repaired.

I got the part back two days later and reinstalled everything, and ran a test roast through.

everything is NOT right.

despite a long talk with tech support in corvalis the roaster is not operating as it should. the roasts are running around 2-3 minutes slower than they were. the only thought I had is that the impeller placement is more sensitive then they were trying to tell me. the roast progresses at about it's normal speed until it nears first crack at which point the beans almost stall in their progression. my best thought is in it's new placement the impeller is moving too much air to allow the beans to progress as they were.

can anyone out there confirm the effect of impeller placement with regards to roast speed and volume of air moved.

should i be affecting change at the burner to compensate for the increased air volume? or instead try to dial in the impeller placement?

thanks
chris