Quest M3 Mods - Page 7

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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#61: Post by AssafL »

Here is a picture. It reeks of amateurish "monkey with a drill" abandonment with an underpowered Makita... I apologize.

Edit - Upon reflection: lets call the workmanship utilitarian (rather than shoddy).

To compensate - Here is the controller. Hopefully, it doesn't look as amaturishly done as the drilling.

Scraping away (slowly) at the tyranny of biases and dogma.

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#62: Post by FotonDrv »

That is almost a total rebuild of Quest! Good job :D
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#63: Post by AssafL » replying to FotonDrv »


Sometimes a hole is the entire difference between two completely different products!
Scraping away (slowly) at the tyranny of biases and dogma.


#64: Post by OldmatefromOZ »

FotonDrv wrote:OldmatefromOz:
That is almost a total rebuild of Quest! Good job :D
Thanks, I am very happy with the modification.
AssafL wrote:LOL.

Sometimes a hole is the entire difference between two completely different products!
Good to see your modification is working well. Even in its simplest form just drilling a few holes like you have to allow more air through the drum is something I suspect a lot of quest owners could do themselves and reap the benefits.

Some additional updates to my situation.

I have gone back to using the original single hole for airflow. All my slots are now blocked off with aluminium foil. The silicone bung I had blocking the original hole could not stand the constant heat and cracked up after around 10 roasts.

In hindsight I should have gone with my first instinct to try the new drum with the stock hole like TomC did. If I was going to cut the slots again I would only make them 40mmL by 2mmW, instead of the 5mmW = too big.

I am actually much more comfortable with how the roaster performs using the stock hole and I am getting some great results. I have been playing with lighter / faster/ high airflow with some high grade Kenya and Rwanda and getting much better development. The spike at the end is after the roast was dropped.

I have pooched quite a few roasts learning to handle the different dynamics. Feeling pretty good about it now though. Overall I have experienced a greater level of agility / control and SMOOTHING of operation in general. :D

Also revisiting with another_jim technique of 4/4/4-5 for caramel bomb coffees. Back to caramel bomb coffees

Compared to when I last tired this I have much more control coming into first crack and maintaining the gentle / steady stroll to the doorstep of 2nd without actually getting any snaps or divots or oil spots.
Early results are CLEAN, complex caramel goodness.


#65: Post by UliD »

In Kaffee-Netz ( ... ass.94152/) there's been a discussion about a different way of modifying the airflow. The original inlet is closed, a new one is opened in the middle of the bottom of the shell and the air drawn through it is preheated with a heat gun.
Probably the improvement is caused by the increased airflow during first crack, when the power of the Quest can be very much reduced and the preheated air allows to comfortably drift to the end of the roast. Examples of profiles: ... 81/page-18, Post 351.
The roasts I tasted are clearly better than my roasts on my unmodified Quest.

Toms modification seems more logical and more flexible to me, as the air is drawn quite freely through the drum instead of being squeezed through narrow spaces at the end and the front of the drum. I'm just afraid that the air might be too cool, but as Tom writes this does not seem to be the case.

Tom, James and Assaf, you have this modification for some weeks now. Are you still happy with it? Do you have further suggestions after those weeks?

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TomC (original poster)
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#66: Post by TomC (original poster) » replying to UliD »

I love it. I seriously think the Quest should come this way. I've also removed the metal "window" vanes of the stainless body/case, to reduce airflow restriction as well.


#67: Post by OldmatefromOZ »

I am very happy with the modification.

Since my last post I have painted the outside of the drum black again. I had done previously quite some time ago and removed it after a while before this mod was even being discussed.

For me this has complemented the new / greatly increased airflow very well and completes the modification.

As mentioned earlier I really did not like the performance using the slots in the side of the shell and that I made them too big did not help (they are blocked up). The original inlet hole works great, I roast inside so no dramas with air being too cold.

I have moved my fire blanket insulation so that it hangs over the exhaust tube above the outer shell. I was finding it hard to slow down the roast with it wrapped around the outer shell.

I have been chasing nailing down this well known style of roast to the letter. Like it or not and without " gushing " too much, the quality and consistency I can now achieve is beyond anything I have been able to produce before and is exceeding my expectations.

This is 225g 10min roast

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#68: Post by cuppajoe »

I've only had the M3 for a few months and so far am happy with it's performance. Who knows, somewhere down the line I may try some of these things. Mine is the first version with the thicker drum and I have been getting nice consistent roasts with no tipping or other problems.

What has been bugging me is the way the motor housing and controls are assembled. These machines get pretty 'furry' fairly quickly, especially if doing several back to backs per session. Getting to the cooling fan assembly is a PIA and you can't remove just the fan itself. The only quick disconnect is for the bottom fan, everything else is hard wired and installed with no thought of serviceability. It is assembled like a Chinese puzzle box, with the screws holding the fan bracket being buried behind everything else.

Every time I need to do the major clean I try and work out how to reengineer things for better access. So far I have added quick connects to the cooling fan leads and eliminated a couple screws for the fan bracket. The cooling fan and bracket can now be removed for cleaning without doing anything more than pulling the back covers. This will also greatly improve access to the other components for service. Next cleaning I'm planning to take some more photos for a post showing the process, would it be better to just add it to this thread or start a dedicated one?
David - LMWDP 448

My coffee wasn't strong enough to defend itself - Tom Waits

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#69: Post by FotonDrv »

My 2 cents would be to add to this Thread to keep all this good info in one spot!

As to the rear of the drum with all the holes in the flat plate end, OR, the open end with holes around the circumference of the rear of the drum; which one works best???
That Light at the End of the Tunnel is actually a train

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#70: Post by AssafL »

UliD wrote:Tom, James and Assaf, you have this modification for some weeks now. Are you still happy with it? Do you have further suggestions after those weeks?
Love it - but I'll try to express why: I am now able to roast much lighter (10C less than my previous drop temp) but still achieve a decent level of development (i.e. good flow rate, good refractometer reading, happy grinder, managed sourness, etc.). I actually doubled up on the area of the holes I drilled.

I am trying something else now - I fit a brass pipe (actually a shim rounded makeshift) through the rear inlet hole so that air flows through the pipe and released into the grinder 3/4 on the way in. My hopes are that I can introduce beans at a lower temp and then rise faster - will update if this actually helps.... BTW - it should be possible to do this mod and fit a heat gun heating element inside - these are cheap enough at 5-10$ a pop...
Scraping away (slowly) at the tyranny of biases and dogma.