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Skywalker Roasts
HarryDog
Top  #101 Print Post
Posted on 09/09/2024 7:32 AM
I have a PWM controller that I thought I could just add it? I have finally received most of the belts that I ordered so I have some other options to test as well with pulleys (Gear drives) for the belts. Good to know I should be looking to slow it down. Wanted to see if extending the drum veins to see if that might help as well. Need to find a welder for that.

Need a little work in 3 spots on that curve and it will be be a solid roast for the Costa Rica Tarrazu I have on hand. The chew test was nice, now to let it rest a bit.
 
renatoa
Top  #102 Print Post
Posted on 09/09/2024 8:06 AM
Yes, just insert the PWM driver between motor wires and motor terminals.
The voltage variation will led to speed reduction. Is the only sense of variation, reduction.
No speed increase without voltage increase...

How the belts would cope with the great temperature of the drum flange ?
They are rated for about 90-120C, I think the metal is hotter ... confused

What advantage brings a pulley-belt system ?
 
HarryDog
Top  #103 Print Post
Posted on 09/09/2024 8:44 AM
Yes the heat is of concern, I don't think they are rated for any type of heat. Just needed something to test as it has been 3 months to get some of them, I can look for better options once if happy with the results. I have some ceramic insulation in the back and can move more air with a fan for now.

I hope it will be quieter not running directly on the rear of the drum. Next torque and speed changes.
 
HarryDog
Top  #104 Print Post
Posted on 09/29/2024 5:39 PM
Did 3 roasts 350g Guatemalan, Bali and the Costa Rica all using the Arduino Uno, seemed smooth.
Guat= 13.2% Bali= 14.8%, CRT=12.7% weight loss.
HarryDog attached the following images:
costa-rican-tarrazu.jpg bali.jpg guatemalan_1.jpg
Edited by HarryDog on 09/29/2024 7:33 PM
 
renatoa
Top  #105 Print Post
Posted on 09/30/2024 1:01 AM
90% power , under 6 min FC... realm of heavy convection machines ... confused:
Did you moded it into a fluid bed? Grin
 
HarryDog
Top  #106 Print Post
Posted on 09/30/2024 1:36 AM
I do have a 4" HVAC inline metal fan that I run at max on exhaust and bean cooler (100cfm claims) I don't think it pulls that much but constantly on while roasting. So I'm moving more air then normal for sure. The chew test is very good for all 3, can't wait to test this Guatemalan as I would drink it roasted on my FB. First time on the SW. The other two I have roasted before on the SW.
 
HarryDog
Top  #107 Print Post
Posted on 10/20/2024 4:25 PM
So I did a bit more of a longer roast, Renatoa style 80% max heat, will post back how it tastes but this is what the roast looked like.
My last faster roasts were good but lets see if this improves anything.
HarryDog attached the following image:
bali-blue-moon.jpg
Edited by HarryDog on 10/20/2024 4:34 PM
 
renatoa
Top  #108 Print Post
Posted on 10/21/2024 8:18 AM
It's not "my style", just used the factory presets parameters as a starting point for manual roasting tweaking.
Which factory presets are even more conservative, maximum 70% power and 65% air.
Would never reach RoR 20C/min with those values.

There is a big question sign for me too if a good thing to push heat absorption so fast, as for a fluid bed, but without the heavy convection of a FB... confused
And how well this kind of IR, which is not NIR ! penetrates the bean.
What we know as sure for now is that IR does not penetrate solid obstacles... so only the superior layer of beans pile absorbs heat, then yields a part of this energy to the other beans by contact/radiation, while the drum is rolling.
For me this heat transfer style suggests a minimal time is required to achieve a homogeneous mass of equally developed beans.
Any power increase means some beans gets more energy than the others, and less time is available to share this energy with the others.
 
HarryDog
Top  #109 Print Post
Posted on 10/21/2024 11:49 AM
Hi Renatoa, are you referring to the Drying Phase ROR? Last roast is 17.1C/Min.
What do you think is a valid ROR for the Drying Phase on this roaster?

For me manufacturer settings most of the time yielded under developed coffee.
To mitigate this I roasted hotter and to certain drop temps.
 
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