Hi guys

I am busy with a project where I am designing and building my own profile controlled sample coffee roaster. The project is quite massive and forms part of my studies for the next year.

I just have a few questions that I was hoping you might have the answer to:
- How big should the roasting drum be for about 1-1.5kg per roast? (diameter and length)
- What type of material is the best? Steel or stainless steel? Stainless is nice, but extremely expensive and requires special welding.
- How thick should the drum material be to be able to evenly conduct heat? It should be thin enough for quick heat adjustments.
- Does anyone have some schematics on a chaff filter? I'd like to build a simple cyclone based filter, but would appreciate some exact measurements.

Thanks guys. Hope you can help! I'll keep you updated with my progress

Hi Neil
I suggest you look over some of the projects here http://www.homeroasters.org/php/forum/viewforum.php?forum_id=32 or this one http://www.homeroasters.org/php/forum/viewforum.php?forum_id=63

- How thick should the drum material be to be able to evenly conduct heat? It should be thin enough for quick heat adjustments.

I think if you want the exact answer you should do a simulation on computer. Maybe a bit of work to set it up. But once you have it, you can make the different variable to vary and see the result (thickness, material, shape, etc.).