Chaff not going in the chaff collector

“Use more fan to get the chaff out as it can lead to smoky flavors”-thx

I never had this issue with my gas drum as even at low fan speeds all the chaff was sucked out.

Hey Brian, I came here looking for a similar explanation. I “vacuumed” my chaff collector after my most recent roast and I swear there was next to nothing in it…now the cooling bowl was another story! I had to remove the hot beans/bowl just so I can vacuum the chaff clogging the fan so I can I cool it in time. Final fan speed was F4. Perhaps I’ll punch it up just before dropping, I just don’t want to suck out those last precious bits of momentum leading up to my finish. Have you played around more with this since?

I get virtually no chaff at the rear collecting area where the rubber dump plug is, the ratio from dump/cooling tray to the rear area is something like 80/20. It all staying in the beans.

I tried running higher fan earlier (F4 before yellow) on one of my last roasts but same issue. I’ll run it higher next time.

I also think I’ll try a roast without the collector cup and see what happens.

Thanks for the airflow path clarification Bruce.

From my experience with my Bullet that Seems odd. Just to confirm-

  • are you roasting with the bean chute plug in place? If that’s left off or if the funnel is left in the bean chute, that will cause the exhaust fan to pull air from the bean chute instead of the drum.
  • there’s a small seal between the (sort of) rectangular transfer tube to the chaff collector- you should be able to see it when you remove the chaff collector. It serves to keep the exhaust fan from getting air from anywhere but the transfer tube (again- sort of; it’s not a perfect pressure seal). If that seal is missing or damaged the air flow from the drum will be affected.

Bruce

Edit- as a comparison I am getting enough chaff in the collector that I must vacuum the collector every other roast or the air flow will be affected to the point the Recipe-driven profile doesn’t track properly.

Which makes me think- have you run the Calibration on the exhaust fan? or for that matter confirmed the air flow exiting the rear of the Bullet? It would be pretty extreme but I wonder of there’s a exhaust fan motor issue… ??

Hey Bruce-

Thanks for your assistance.

I have the chute plug in place for most of the roast. I do gently lift a corner a bit to listen to 1C but the impact due to duration and amount of lift can’t be much.

I’ll check out the seal between the rear transfer tube and rear chaff collector.

I do vacuum the tube out between roasts (shop vac, bean chute plug off, hand briefly over rear transfer tube exit) to clear. There is usually not much in there or the rear chaff box but a ton in the cooling tray.

I’ve not calibrated the exhaust fan. Will read up on that.

I do lose a bit of chaff out the lower part of the front door during roasting but no beans. I think the door is shut pretty well but know it can leak sometimes. I did review SM’s noisy drum returned unit video. My drum is pretty hard to turn when off and makes a bit of noise but the spindle is only out the front by 1 mil+/-. I’ve not mic’d it.

I do the same- haven’t seen a noticeable effect.

I mentioned vacuuming the chaff collector to give you a sense of how much more chaff I’m seeing than the 20/80 ratio you mentioned. Just confirming for you that there seems to be a hardware problem. I only rarely see anything in the transfer tube, so if you’re finding something there to vacuum then exhaust air movement is probably lower than what I see.

You should see chaff dribbling out the front of the Bullet below the door- that’s an intentional part of the design. The fan located at the rear of the Bullet guarantees some air movement to carry that little bit of chaff out the front. It’s as it should be.

The drum shaft protrusion doesn’t sound in any way remarkable- probably just fine. The real criteria is the spacing between the front of the drum and the face plate. If you aren’t hearing any scraping and you aren’t getting beans trapped in front of the drum then it’s likely ok.

As a point of reference I roast at F2 till near the end of the roast when I up the fan to F3. I’m not using a huge amount of fan which of course would affect the movement of chaff. The only time the exhaust fan gets higher speeds is during the Cool mode when I’m shutting down.

Bruce

I’m also hitting into this issue… and I don’t think I’m doing anything too different.

I ran 4 roasts yesterday, and I went to clean the chaff collector this morning, and it was completely empty…

I did notice on my last roast, there was a ton of chaff at drop.

Would this point to a fan issue?

Reviving an old topic, but I now own two bullets and my main one seems to collect chaff underneath the drum. I still get quite a bit falling out (that’s fine) but it seems to clog the air flow by the drum. Meanwhile this new to me bullet has next to no collection of chaff by the underlip of the drum. Any idea what could be causing this?

You might want to check this thread…

Deep and Deeper Cleaning - Taking Care of the Bullet R1 - Roast World Community

Also, if the chaff is not going to the collector, your exhaust tube might be clogged. In that case, there’s this thread…

Long brush for cleaning the air transfer tube and bean chute - Taking Care of the Bullet R1 - Roast World Community

But I think the second is more of a problem for the person who posted a year ago right above you.

Thanks, i do experience the symptoms of the first link but the issues is more related to the chaff being stuck between the insulation and the drum at the door. I usually get a layer of chaff:

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Just maybe, this could help. You will forgive me, but it’s difficult to know exactly what’s happening when you don’t see it. This is what comes to mind…

Roaster is dropping green beans into cooling tray - Taking Care of the Bullet R1 / Bullet R1 Cleaning - Roast World Community

You could also try adjusting the drum a tiny bit forward.

I feel you. My Bullet does not roast like it used to.

Between batches, I am vacuuming out chaff from the front. Though I don’t have a build up.

First thing to do when you have an airflow issue is to take about the chaff collector, and rebuild it completely. A loose bolt can cause airflow issues, which can redirect the heat, which can warp the plastic, which can cause another airflow gap, which can cause more issues… etc, infinity.

I’ve not had a batch I’m happy with in maybe a year. Drinkable, but not good. Always some major issue in the cup that brings it down.

I have found burnt chaff in the machine when I’ve cleaned it out, which accounts for some Smokey flavor issues perhaps.Which is also an indication some air is not moving.

…fwiw, I’ve seen million dollar setups get shut down due to airflow woes, so I’m not saying the bullet is alone in having airflow issues, but there are specific short comings that have to be accounted for in any system.

Is there a way to ensure it stays in that position?

Good point. I’ve down two tare downs so maybe I didn’t put it back together well. I just find it odd that one has chaff getting stuck and the other doesn’t. I could measure how far the drum is from the front plate to check

The metal plate section has to interleave with the plastic tab grooves on plastic casing side.

And the rear gasket I’ve seen chaff build up there, and in the main duct. As if things aren’t blowing down. But maybe there’d be too much heat loss if it weren’t that way?

Anyway, I can’t get a balanced even roast out of my bullet that doesn’t suffer from some roast defect. The cup I’m drinking this morning is passable. But it feels like I am cooking on a stove top with a draft in the room, and never getting reliable heat application, and not getting even or predictable results.

Also, I used to see a nice stream of smoke coming up from the vent, even at F2 and F3, but now I don’t. The exhaust is kind of invisible and gentle, even at F4. But somewhere around F7 something changes and suddenly it is both surprisingly low draw and drawing too much at the same time. I’ll mess with my fan calibration again, as I just updated my software and about to update to firmware 610.

I haven’t had a tasty roast in over a year. Pretty much since moving up to 1lbs, i have never gotten much that I am happy with. Though the occasional 200-250 gram batches come out nice. (At 1lbs, i do get nearly good batches, but never a fully good one. Like the cup I had this morning was almost good. )

Also, I believe, depending on how you position your rear vent (hampered wheel) fan, you may get more or less suction. May have to confirm with aillio support on that.

I’ve replied in the other thread, but let me just say that leaving the door open while in cooldown will not affect roasting. It might influence the cooldown process (faster or slower, whichever it is), but once you start roasting and close the door, the machine does not remember it was open before.