So far this cyclone has worked out great. All chaff stops at the collector stage with nothing out the end of the exhaust tube. When I drop a roast just turning up the fan speed to max and watching the roaster temp decrease I can be ready for the next roast quite quickly. Makes for great back to back roasting.

I added some insulation behind the PWM controller along with a bit of aluminum heat diffusing to keep it cooler. It runs quite cool even on hot summer days.

It's great to have an improved roaster setup!

Update and evaluation:

This chaff collector has been working great for my Kaldi Fortis (600g) roaster. Here are photos of the chaff after 15kg being roasted. (400-500g batches)

The chaff bucket freshly opened. You'll see there is lots of room for the air circulation; a key to getting good particle fall from a cyclone!


At the end of my exhaust hose I have a stocking cover to catch anything not caught by the cyclone collector. I haven't changed or cleaned this stocking from the beginning. You see a little color from a little bit of dust that gets out, but that's about it. During the winter I throw the exhaust hose on white snow and after roasting 1kg the snow is melting a bit, but still white. Collector is working well.


The uncompressed chaff from 15kg of beans. Fills a normal plastic grocery bag up.


I think overall it works really well. For anyone making their own I would recommend that your chaff bucket be quite large for good separation. Undersizing the receptacle seems to be the biggest mistake we can make. Round collectors also excel when compared to square ones due to wind turbulence and eddies in the corners of a square that disturb the fall of debris.

Now it can fertilize the plants.