Quest M3 Solid vs. Perforated Drum - Page 2

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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AssafL

#11: Post by AssafL »

Hmm. Good thought. Will make getting at the grub screw easier as well...
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jjack (original poster)

#12: Post by jjack (original poster) »

Stephen,
The drum was ordered as is from Quest, so I didn't drill the holes. I didn't measure them beforehand but my best guesstimate would be 3mm diam.
The case is stock. I will be doing another roast to test power/fan changes in a little while. As soon as I have something worth sharing, I will post.

The other mod I would like to do heat-wise is a copper tube extending from the air intake to the middle of the drum so air has more time to heat and has a more even flow. That is only in the planning phase as I would have to source appropriate tube.

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FotonDrv

#13: Post by FotonDrv »

AssafL wrote:Hmm. Good thought. Will make getting at the grub screw easier as well...
It is really clear that the fan/air flow is the Achilles Heel of the little machine and I believe TomC was the first reference I saw (could have been others) talking about those louvers.
That Light at the End of the Tunnel is actually a train

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TomC
Team HB

#14: Post by TomC » replying to FotonDrv »

No, I chopped mine off after thinking about it for a bit, but someone else did it before me.

With all the modifications we're doing for our own personal use, we can throw any "user protection" out the door. The slats in the exhaust only create more airflow restriction. I've long since cut them off with the Dremel. I'm still playing around quietly with different insulation methods for the rest of the roaster, but it does exactly what I want it to now. Big blue might get sold, seeing how I don't need the capacity. The modified Quest does everything I need, since I'm focused more on precision than batch size.

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FotonDrv

#15: Post by FotonDrv » replying to TomC »

Interesting observations! Thank you :D
That Light at the End of the Tunnel is actually a train

jjack (original poster)

#16: Post by jjack (original poster) »

I have been playing with fan and power settings during the roasts, trying to modify the curve to fit a particular math plot.
In following a fast start slow finish kind of roast, did a roast with the same coffee used for initial testing. Here is the result:



Almost a perfect cubic equation.
I see the advantage of the perforated drum as being able to control the roast profile more precisely. Power settings will show quite quickly compared with solid drum. Also fan speed settings have a significant greater impact on profile.