I roast indoors (no wind, temp ~22, humidity ~40) and, when this happens, it’s always before I’ve had a chance to act on the “charge” suggestion. So, the door is closed and the bean chute is plugged.
Since I can clearly see the IBTS temp, I know that it is not dipping by 80C. That leaves the ROR from the probe going to -25, which I wouldn’t see, since the graph doesn’t show negative values. (It’s pointless to stare at the Bullet’s main display and hope to see momentary excursions.)
The only thing left that could possibly cause this is an exhaust fan set-up that I have. It has a piece of 4" flex duct perched about 3 cm above the exhaust outlet of the roaster. It has a variable speed 24 VDC muffin fan in an down-stream piece of rigid aluminum duct, which is controlled by a cheap PWM controller I got on Amazon. I thought that the 3 cm gap would be enough to keep the fan from affecting the roaster temps, but maybe not.
I’ll try to come up with a larger hood-like set-up and give the roaster some more space. Maybe that will do it.
I did another roast today and just after cleaning the sensor last roast, near the end of the roast I got the A-01 warning. The fanlight went to FA and I could adjust it rom FA to FC to F6. The adjustment did nothing and the machine beeped until it cooled right off. My guess is that cleaning the sensor had nothing to do with it.
In any event, I removed the chaff collector and the fan was turning very slowly. It would slow down the sped up slightly regularly.
I’ve bought a large rectangular cake pan to use to build a vent hood. I may have some time on Monday (the US Memorial Day holiday) to work on it. I’m very anxious to see if I can decouple that airflow and avoid “ch-roasting” any more coffee. It may even help support my large batch roasting!
@celticcupcoffee - Here’s what I created to vent both the Drum and Bean Bowl into a single collection box. The box captures all smoke and odor from the ass-end of the Bullet. It is then sucked out through a single vent hose via a variable speed fan. Works great and I’m not getting any errors during roasting.
@celticcupcoffee - I got the plastic hood on Amazon (linked below) and it was the perfect solution. My thought was not to have anything directly contacting the exhaust of the Bullet. This hood sits a few inches above the Bullet’s exhaust to collect whatever comes out and direct it down-line.
That 4" clear duct hose fits right onto the back of the Bullet’s Fan area that draws cool air through the bean cooling bowl. It doesn’t require any fitting on the fan end, but I do have it connected to a 4" mounting flange on the Exhaust Box lower area. When I cut that particular piece of 4" tubing, I cut it just slightly long so that it had just a slight amount of forward spring-pressure to keep it pressed to the backside of the Bullet’s Cooling fan.
I love that clear 4" tubing because I can easily see if I have any debris or roast-dust collecting in the tubing. Thanks to the excellent exhaust and filtration of the Bullet’s design, that entire exhaust chain of the Tubing, my Collection Box and the variable fan are all staying clean. Good going Aillio!
The box is just standard foil-lined sheathing that you would use on an exterior wall of the home. I had enough of that laying around from a prior project, that I grabbed it and built an enclosed box from it. I mounted that plastic vent hood on top and sealed everything with foil duct tape. It isn’t a “thing of beauty”, but it works like a champ.
@jacob - That’s where having a Magnehelic installed onto the Bullet can come in handy.
With my setup, there is no air-flow change (within the Bullet) due to the variable speed fan that is down-line of the smoke collection chamber. The variable speed fan (on low speed) simply helps push the smoke and odor outdoors. The only thing that changes airflow/pressure in the Bullet (as measured by the Magnehelic) is changing the Fan speed of the Bullet itself.
