To remove every other blade, did you cut them off or did you manage to disassemble everything (I can’t do it myself, it feels like they are also glued…)
I used an exacto knife to get under the folded over ends of the blades on the outside of the squirrel cage and bent them up on both sides of the blades. They were not glued on the fan rails that I modified. Then I used a pair of needle nose pliers and carefully bent the blades inside the rails and they came right out without damage to the outside rails or the other blades.
I did not disassemble the fan.
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Very impressive solution, thanks for sharing.
In B2B mode, do you move the piping away from the exhaust when you ramp up the shop vac to 100% or is this not needed? I’m just wondering if all that airflow makes pre-heat take longer between batches.
I don’t move the piping away. Because there is an air gap between the mini collection hood and the bullet exhaust, it doesn’t suck any of the hot air out of the Bullet.
I roasted 6 batches of 750grams of green beans today without stopping.
I roast 750g batches because I am using 1/2 gallon Mason jars with fermentation vacuum locking lids. If i weigh out 1 kilo of green beans, the 1/2 gallon jar can’t hold all of the beans after roasting because they have expanded too much.
These lids have a vacuum lock on them and come with a small hand pump.
I typically use recipes for my roasting. With this new setup, my preheat between batches is typically only about 5 minutes. And since I don’t have to stop and empty the chaff, I can roast more batches in less time.
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Neighbors don’t care. My backyard is crying for some better management 
I concede. Any chance you could share the .stl files for those tees and elbows you fabricated? I’m going to have to rework my setup
I would gladly share those files with you but they are very disorganized. I had a lot of problems getting the fits just right with the fittings.
I used PLA filament for printing. It has a very low melting point and trying to get the fittings to print without collapsing was difficult.
I tried using ABS filament, but it is much more difficult to print.
I had a large box of unusable fittings.
I ended up sanding most of the fitting IDs and then using heat resistant silicone caulk to hold things together.
I originally used clear PVC pipe. I thought it would be cool to see the chaff moving through the system. Unfortunately, the PVC pipe couldn’t handle the heat and collapsed under the vacuum in the pipes.
I changed to Chrome plated 2.5 diameter OD steel pipe. I got it from Amazon.
I think that a more forgiving solution for the fittings would be to find hard rubber fittings and use them.
The Y fitting was the most difficult to print. Printing that fitting took six hours. (and it still had to be sanded to fit) I printed a few of those trying to get it just right. ( A few times 6 hours each)
The CAD/CAM side of building these fittings on the computer wasn’t too difficult for me.
My Day job is developing manufacturing processes for aerospace components.
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A little update on my side, I tried to hook up a small (very cheap) shop vac to my system (very similar to @billc ) but it’s way way too loud for me, even using the speed controller, it’s either too slow doesn’t suck anything or so loud I can’t tolerate it for a full roasting session… (can it be related to the use of 220v in europe ?)
I will try to print some 3D parts to adapt it to the inline vent I have as it is quieter.
Would you mind sharing the stl file for the baffle inside the chaff collector ? 
Sorry to hear that the vacuum didn’t work out.
I typically run the vacuum at about half voltage which is not too loud. I can see the chaff leaving the bullet and getting sucked up into the little vacuum hood.
Then when I start cooling the beans after dropping them, I turn the vacuum up to full speed for about 4-5 minutes until the beans are cool.
The Vacuum is loud during cooling.
The reason that I chose to use the 2.5 inch OD pipe, is because that is what the fittings of the Cyclone filter were.
Here is the STL for the baffle
Aillio Bullet Chaff collector partition.stl (86.6 KB)
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Great idea with the jars. Do you just buy the lids? Will they fit a standard mason jar? Where did you get that setup with the pump?
I buy these lids from Amazon. They come with the hand pump. They fit all large mouth Mason jars. After pumping the jars to pull a vacuum, the jars will maintain that vacuum for several weeks. (freshly roasted beans will outgas carbon monoxide and the vacuum will be lost, but that is okay because the excess carbon monoxide will be allowed to escape and no oxygen will enter the jars and degrade the quality of the roasted beans)
My local Walmart in southern California has 64 oz (1/2 gallon) mason jars available for ~$17.00 US.
This is similar to the wine-vac system that is sold.
Edit: These lids work with any of the Mason Wide mouth jars: pint, quart, half gallon…
I typically have several jars with different roasted beans in them and can have a different coffee variety every time I brew.
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That’s awesome because I always have a cupboard full of different beans in mason jars. I was about to buy some of the metal Airscape cans that we sell now in our shop but they are pricey even with my discount. Gonna order some today!
Thanks
Another thing that I find interesting is when I am pulling a vacuum with the hand pump, I get a good strong dose of the aroma of the roasted beans.
While I am thinking about it, I told a friend about the fermentation lids and he loved the idea and bought a bunch. He was telling me how much he liked them but complained that they were hard to open after pulling a vacuum. I watched him open a jar and found that he was just trying to unscrew the lid, I showed him that all he needed to do was push over the little silicone vacuum lock with a finger tip until he can hear the air rushing in and then the jar will open easily.
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Ahh nice that is good to know. I have the set of 6 and the pump coming from Amazon today. Thanks for the info and the tip on these!