Thanks!

There is a 1/4" gap between canning funnel and dog bowl that allows air and chaff to escape. I found this escaping air is hot enough to raise and warm the heat gun to a level where it could shut down mid roast (as it did when hand holding the gun). The top picture shows my fix, which is an aluminum shield that surrounds the bottom of the heat gun. Not pretty, but works.

The issue is, the MET probe, heat gun and shield must be removed quickly to dump the beans into my cardboard box cooler (which works very well).

If I re-design this heat shield to instead sit down around where the hot air escapes and perhaps add a blower, it will accomplish getting rid of hot air and collect chaff. But if I am not careful with the design, it will hinder the quick removal of beans and get in the way of visually inspecting the beans as they roast. Right now, I am not planning to do much more modifications. Perhaps tidy up the wiring to make more robust and add some more insulation under/around the dog bowl.

My focus in the next month or so is to roast coffee with this consistent setup. Learn a bit more about coffee roasting and bring my quality level up a notch. At the moment, I feel like my coffee is in the ball park. But I got a ways to go before it is good. I need some practice that only a ton of roasts will hone.

Disaster roast #16. . .


Long story. I moved my roasting outside and ran my master varitemp heat gun off my nice Honda 3KW inverter generator.
The generator has clean output, but for some reason it interfered with the heat gun control resulting in max heat for all settings of the knob. I found this out too late in the roast and scorched, tipped and burnt the coffee. The beans that look ok, are way underdeveloped.

Not a complete loss. I learned the true limitations of my roaster and how this intense heat resulted in a very uneven roast. So, I am wondering if my agitation is too slow. Another mod may be coming, since my motor is fixed at about 80rpm.

Roast #17 did not have the issues of 16. I used a short extension cord that seemed to do the trick. However, I did push the roast harder than other roasts. My MET was about 700 just past drying and I lowered temps just prior to FC. It was a Kenyan, so I thought this might work. Total roast time was about 11min. Well, it didn't work. Lots of ashyness. No visible tipping or scorching, but it tasted bad. Profile on artisan looked pretty good. Nice steady RoR through development. I dropped a little late at the start of 2C.

Tomorrow, I hope to run a few back to back roasts. Kenyan and a Colombian. I plan to bring my MET way down and see what tastes result. I now have the roaster connected to artisan and logging BT and MET. My MET is basically the air from the heat gun, which is buffered a bit with use of a stainless scrubby pad. But it seems very hot relative to other folks profiles. We will see soon if more mods will be needed.


I am having a sinking feeling that my roaster won't do great roasts. I am certain it will do ok roasts, but I think the airflow by the beans is not great enough. The roaster would need major overhaul fix. If that is the case, I may bite the bullet and get a Quest M3. Based on some posts, the Quest is a great little roaster. Time will tell . . . .

I also started with a West Bend Popper 2 then Popper I. I made all the mods I could find on this and other forums like varying the heat, measuring the bean mass temperature, different profiles, etc. It was a wonderful way to learn about roasting. Like a previous poster I wouldn't change a thing in my roasting journey.

Because my friends were bugging me for my coffee, the small amount I could roast in a popper was very limited. A friend of mine, Peter from Green Coffee Buying Club, convinced me to try a West Bend Stir Crazy with a Turbo Oven.

Again, I did all the mods found on this and other forums. The short coming was the Stir Crazy's weak and sensitive motor. Again through the help of forums, I found a new motor modification and now roast just over 1 pound at a time with excellent results. You can see my roaster and motor mods at http://www.bobbooks.net.

I think one of the biggest assets in successful roasting is leaning the intricacies of the particular roaster. I learn something almost every time I roast about my roaster and how it reacts to different roasts. To plagiarize a baseball reference of a Yogi famous quote: It is about 95% art and the other half is science.

bobbooks wrote:I think one of the biggest assets in successful roasting is leaning the intricacies of the particular roaster. I learn something almost every time I roast about my roaster and how it reacts to different roasts.

I agree. I learned a lot building this thing and now have leaned a few intricacies. I started roasting thinking it was all about temperature and time. Now that I have built this roaster, and it isn't perfect, I certainly have a better appreciation for many features of roasters. For instance, I really wish I had a trier so I can get those beans right up to my nose. I have trouble viewing my roast with my rig. Next roaster, will have a nice view port. A bit more thermal mass would be good.

Today, I added some insulation to the bottom on the bowl and wired in a 20A outlet for roasting out on my garage. Tomorrow, fingers crossed, should result in reasonable coffee. Probably not optimized profile, but something worth sharing.

Thanks for your support. This forum has had me glued to the details of roasting for the past month. I'm lovin it.

This morning I roasted three roasts. First, I had an issue with my heat gun overheating and shutting down just at at end of yellow. I cooled it, reset and continued. But I suspect it won't be the best. The coffee lost only 15 percent weight, so it might be drinkable.

The later two roasts went quite well. Kenyan and Colombian. Can't wait to pull a shot!