Mine was ultra clean, even the first one that failed. And everything is snapped in tight. Part of me is worried there was just a bad run of fans. Not sure if itās supposed to be this way, but none of them spin freely. Theyāre smooth but only make a small turn before returning to position. Never really seen a fan do that
Probably normally behavior. Youāre seeing the magnetic poles in the motor stop the rotation. The blades are so short they have very little momentum. The motor has strong magnets and rotating by hand wonāt generate enough momentum for them to continue spinning very far.
Bruce
Got it, thanks. I just figured it wouldnāt have a hard stop like that.
Bruce is right about the magnetic ācogging ā as I think itās called, not a sign by itself of a faulty fan. Itās usually bearings that give out and thatās a different feel.
The only other factors I can imagine might be if you have the IBTS not seated or wires fouling the fan when you put the faceplate back together causing friction which drops the speed. The fan has a speed wire so thatās how feedback comes back. Typical IBTS fan speed should be in the 14K rpm region, so you might want to watch this during a dummy roast and see if a pattern emergesā¦
Of course getting @jacob to review wouldnāt hurtā¦
Since it worked for 3 consecutive roasts, I think I did everything correctly.
Which leads to environmental or other things we know we donāt knowā¦like heat build up expansion or something coming into play. Hence trying to spot a patternā¦can you leave the info panel up and monitor the IBTS fan speed ?
No idea, I havenāt tried that before. But Matt is going to call me tonight and weāre going to try to run a roast over the phone if I can get it out of beeping mode.
*Outside temperature affects everything anyway. Iām sure people roast with their Bullets from 55-85+ degrees Fahrenheit with external temps but that fan is supposed to be stuck at 16,000rpm regardless of external temperature. It really seems to just be a fan to protect the system from reaching a failure/inaccuracy point vs keeping it at XX degrees. Thatās something a heatsink should be able to do in all but the very hottest environments where that little fan wouldnāt do the job eitherā¦ Iām thinking Dubai or Phoenix hot, and roasting outside in the sun
OK, I think weāve got several āfansā crossing the streams here so glad Matt will try and walk through them. Ruling our the exhaust fan (squirrel cage where the smoke comes out) as our candidate, the error you quoted is generally tied back to the IBTS fan which is supposed to keep deposits from smoke off the IBTS lens. Youā're right that the general RPM is in the 14K-16K range and should blow in a particular direction (I heard of folk misfitting them backwards so they suck intsead of blow) and the firmware checks for that as a precaution. It should not be impacted by the ambient temperature (unless you are in Siberia and the fan froze solid!).
There are a couple of fans on the power board which I donāt think are checked by the firmware.
Please let us know how the movie ends though if you and Matt figure it out - enquiring minds want to knowā¦
Will do!!! Hopefully itās a one and done fix, at least until normal wear takes it out after hundreds of kilos of coffee is roasted.
*The exhaust fan got a full cleaning fairly recently(it wasnāt very dirty anyway) and spins well.
The fan keeps chaff off the IR sensor and assures smoke/dust/whatever doesnāt move upward thru the view port toward the IR sensor. A heatsink canāt do that.
Bruce
Ah, I know itās a temperature measuring device so it can obviously get hot. I just figured something in the back of it may be sensitive to overheating.
I wish you could run the roaster without it if need be. Not ideal since thatās a perk of this roaster. But plenty of people roast solely on a bean probe and thatās exactly how Iāve roasted in the past before getting the Bullet.
While that sounds great in principle, the IBTS is used to measure the drum temperature for preheat so if could bypass it, I think you would still be stuck. Having a spare IBTS in a drawer would seem the best option.
Perhaps you have tightened the screws holding the fan too hard? Then it might not spin freely enough. Try to loosen them a tiny bit. You could even do this while power is on to see if the RPM goes up.
Iāll try that. But it worked fine for 3 roasts with the first of two fans I got. Matt even said the RPMs were good for those roasts.
Another thing just to check is which fan did you get? Did it come with an extra bracket? Newer fans are taller and needs an additional spacing bracket to be installed.
The fan part number is AG02005MX107300, the video of installation can be found here:
https://vimeo.com/583212663
Not sure, Iām at work now. But Iāll check when I get home. I wish that was actually mentioned in the video though. You can see the fans are a different thickness. But thereās no mentioning of spacing differences with a bracket and no bracket was included. I also just wish everything had a torque spec(and torx bolts) so there would be no issue with anyone choosing their personal tightness for any of these parts.
*It also still worked perfectly well for 3 roasts. Still no idea how that would be if I installed it incorrectly.
Fan on the left is what came from factory. The fan on the right is the one that lasted 3 roasts. So theyāre both the original sized fan. Iām guessing thatās also what made it into my roaster for the 3rd fan.
I donāt think we have a toque rating for the screws holding the fan, might be so little to reliable do with normal equipment. For M3 bolts you can use 1-1.2Nm
AG02005MX107300 New Green Tall
MF20080V2-10000-G99 Old White short
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left is the original. I wrote the removal date on both but you canāt see the numbers on the one on the right so I tried taking it off with acetone and that took the model number offš Either way, they look the same. Itās not the new, thicker fan
I paid for one and got the other one as a warranty. Should these white labeled fans no longer be getting shipped out?