Just 2, but that is enough even for a 1000g roast.
Remember it is a work in progress. LOL
The nylon mesh bag is sold by Amazon as a fruit protection bag.
It is hard to see from the photo, but there is a 3d printed adapter mounted to the back of the fan. I took some aluminum wire and stuck it in the bag to hold it open.
The split collar allows me to set the depth of the stirrer wires so that they don’t rub on the floor of the bowl.
As I said: it is a work in progress…
@krame and @billc - Curious, the mesh produce bag you’re both using, what material is that? I am seeing a lot of different material on Amazon including ones that are polyester+plastic! I would be a bit concern with the plastic/poly blend given that the air is a little hot when beans are dumped. I also see cotton and nylon ones. TIA.
They’re the plastic ones you’re thinking of. Dropped 900g of rolling second crack without issues.
Cool
I just now finished my first roast with the “New and Improved” (imagine trumpet flare sound effect here) Chaff Sock.
The ones that I bought are nylon and heat is not a problem.
The 10 X 14 are too big (and there are 50 of them) I took one and cut it to fit better and then used a stapler to sew it to the size that I wanted. (I don’t have a sewing machine but the stapler worked fine)
There is no chaff left in the cooling bowl tray (no vacuuming needed) Note that the white filter material was left out. The chaff is forced through the fan.
You could do a lot of roasts before having to empty the Chaff sock. The only down side is that there is a fair amount of dust that is created that gets through the mesh bag. I am in the garage, so that is not a problem for me, but in a kitchen setting, it might be messy.
Thanks @billc for the detailed video and photos. I may need to go with something with finer holes and see if it works better with the dust. The semi rigid vent hose I am going to insert this in may contain some of it but less would be better.
A nylon stocking might work. Cheap enough to try.
You could also try using a length of 4" dryer duct with a nylon legging on the end. The whole after fan construct doesn’t have to be just the bag.
I am using a semi rigid duct but I need that to direct the exhaust closer to my vent hood to vent outside. My setup Exhaust hood options - #41 by blacklabs
I wonder if a vacuum cleaner bag would work. Maybe needs more powerful airflow.
I think vac bags maybe too restrictive. The nylon stockings would work but they do get runs when snagged onto something. I am also looking at those reusable cotton coffee socks as an option…
Nylon nut milk bags may be the optimal solution. I have one that I got for my wife for making yogurt. It is a 200 mesh and air passes through it easily. Better, I think, than cotton would.
Amazon also has 100 mesh nut bags.
They have mesh bags under the same listing for 100 mesh, 200 mesh and 300 mesh
I will try it out. (I wish I had thought of this before I ordered 50 fruit saver bags)
I wonder if @Krame can come up with a GIF for this that is not totally obscene…laughing already.
I just roasted 500g of a Honduran washed. It didn’t have much chaff, but the nut milk bag didn’t let any dust escape. I need to try it with a natural Ethiopian to really test it.
The grid on the left is the fruit bag, the grid on the right is the 200 mesh NutMilk Bag. The holes in the nut milk bag are probably about the size of a human hair.
oK. This has no right being as awesome as it is. I just tried it, and I’m never going back.
Thanks 
