Flat vs. Conical in a slightly different light... - Barista Exchange2024-03-29T09:08:53Zhttps://www.baristaexchange.com/forum/topics/flat-vs-conical-in-a-slightly?commentId=1688216%3AComment%3A674123&feed=yes&xn_auth=noand yes :)
Fraser Jamieson s…tag:www.baristaexchange.com,2009-11-05:1688216:Comment:6800012009-11-05T18:47:13.666Zmark konczhttps://www.baristaexchange.com/profile/markkoncz
and yes :)<br />
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<cite>Fraser Jamieson said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/flat-vs-conical-in-a-slightly?x=1&id=1688216%3ATopic%3A671751&page=2#1688216Comment674410"><div>And yes, because even if the engineers know what they're doing, companies are usually run by accountants and MBA grads. ;)</div>
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and yes :)<br />
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<cite>Fraser Jamieson said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/flat-vs-conical-in-a-slightly?x=1&id=1688216%3ATopic%3A671751&page=2#1688216Comment674410"><div>And yes, because even if the engineers know what they're doing, companies are usually run by accountants and MBA grads. ;)</div>
</blockquote> And yes, because even if the…tag:www.baristaexchange.com,2009-11-01:1688216:Comment:6744102009-11-01T16:51:02.349ZFraser Jamiesonhttps://www.baristaexchange.com/profile/FraserJamieson
And yes, because even if the engineers know what they're doing, companies are usually run by accountants and MBA grads. ;)
And yes, because even if the engineers know what they're doing, companies are usually run by accountants and MBA grads. ;) agreed, a single fan in the g…tag:www.baristaexchange.com,2009-11-01:1688216:Comment:6742922009-11-01T10:09:09.693Zmark konczhttps://www.baristaexchange.com/profile/markkoncz
agreed, a single fan in the grinder housing is the best way.<br />
are these modifications really needed?<br />
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yes and no<br />
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no, because i believe in the knowledge of the manufactures. these engenieers working on that, better than i can (or we). if you have heating (or quality) problems due to high volumes, you need to buy much more serious grinder! or for serving high volumes you might need to hire an extra barista and an extra grinder and maybe an extra espresso machine (for the smooth operation and…
agreed, a single fan in the grinder housing is the best way.<br />
are these modifications really needed?<br />
<br />
yes and no<br />
<br />
no, because i believe in the knowledge of the manufactures. these engenieers working on that, better than i can (or we). if you have heating (or quality) problems due to high volumes, you need to buy much more serious grinder! or for serving high volumes you might need to hire an extra barista and an extra grinder and maybe an extra espresso machine (for the smooth operation and quality).<br />
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yes, because sometimes these modifications gives noticable differences and simple things can improve the original models. i'm also the kind of guy who like to get hands dirty, and like building something unique. the upgrade gives us fun and good experiment :)<br />
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<cite>Brady said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/flat-vs-conical-in-a-slightly#1688216Comment674123"><div>Agreed, this might be worth trying... but I'm pretty sure an electric or other fan would do a better job. Why?<br/> <br/>
Because, fins are great for drawing heat out of things they are in contact with. They are useless in cooling things that they are not in contact with - any tiny airgap renders them nearly useless. This is why there is often conductive grease under them in electronic applications - to eliminate any possible airgap. If I understand correctly, much of the heat in motors builds up in the windings. Since this is part of the rotor, which is in the middle of the motor and surrounded by an airgap, I'm not sure how effective external fins would be in cooling that hottest part of the motor.<br/>
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What I'd think would work better is a "slinger fan" on the motor shaft, inside the grinder housing. This draws air over the motor, through the middle of the motor, and basically sucks heat out of the motor shaft. I imagine there are some grinders that use this fairly common part to keep it cool, but I haven't run across one yet.</div>
</blockquote> I'm actually inclined to agre…tag:www.baristaexchange.com,2009-11-01:1688216:Comment:6741402009-11-01T02:20:42.494ZJeremy Conleyhttps://www.baristaexchange.com/profile/JeremyConley
I'm actually inclined to agree; but we all know how it goes...<br />
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I just cringe at the thought of the potential marketing point/hype and translation to consumer cost, though. Look at how Mazzer milked nearly an extra grand out of offering the doserless E grinders.<br />
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<cite>Brady said:</cite><blockquote cite="http://baristaexchange.ning.com/forum/topics/flat-vs-conical-in-a-slightly#1688216Comment674123"><div>Agreed, this might be worth trying... but I'm pretty sure an electric or other fan would do…</div>
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I'm actually inclined to agree; but we all know how it goes...<br />
<br />
I just cringe at the thought of the potential marketing point/hype and translation to consumer cost, though. Look at how Mazzer milked nearly an extra grand out of offering the doserless E grinders.<br />
<br />
<cite>Brady said:</cite><blockquote cite="http://baristaexchange.ning.com/forum/topics/flat-vs-conical-in-a-slightly#1688216Comment674123"><div>Agreed, this might be worth trying... but I'm pretty sure an electric or other fan would do a better job. Why?<br/> Because, fins are great for drawing heat out of things they are in contact with. They are useless in cooling things that they are not in contact with - any tiny airgap renders them nearly useless. This is why there is often conductive grease under them in electronic applications - to eliminate any possible airgap. If I understand correctly, much of the heat in motors builds up in the windings. Since this is part of the rotor, which is in the middle of the motor and surrounded by an airgap, I'm not sure how effective external fins would be in cooling that hottest part of the motor.
<br />
What I'd think would work better is a "slinger fan" on the motor shaft, inside the grinder housing. This draws air over the motor, through the middle of the motor, and basically sucks heat out of the motor shaft. I imagine there are some grinders that use this fairly common part to keep it cool, but I haven't run across one yet.</div>
</blockquote> That said, I generally agree…tag:www.baristaexchange.com,2009-11-01:1688216:Comment:6741322009-11-01T02:11:38.738ZBradyhttps://www.baristaexchange.com/profile/Brady
That said, I generally agree that its better to use passive cooling methods vs adding another component, assuming they get the job done. Just speculating on why this approach isn't in use. Sometimes they haven't though of it, but more often they did and it didn't work. You gotta believe that adding several dollars worth of extra components to the grinder wasn't the design engineer's first choice...
That said, I generally agree that its better to use passive cooling methods vs adding another component, assuming they get the job done. Just speculating on why this approach isn't in use. Sometimes they haven't though of it, but more often they did and it didn't work. You gotta believe that adding several dollars worth of extra components to the grinder wasn't the design engineer's first choice... Agreed, this might be worth t…tag:www.baristaexchange.com,2009-11-01:1688216:Comment:6741232009-11-01T02:00:47.460ZBradyhttps://www.baristaexchange.com/profile/Brady
Agreed, this might be worth trying... but I'm pretty sure an electric or other fan would do a better job. Why?<br />
<br />
Because, fins are great for drawing heat out of things they are in contact with. They are useless in cooling things that they are not in contact with - any tiny airgap renders them nearly useless. This is why there is often conductive grease under them in electronic applications - to eliminate any possible airgap. If I understand correctly, much of the heat in motors builds up in the…
Agreed, this might be worth trying... but I'm pretty sure an electric or other fan would do a better job. Why?<br />
<br />
Because, fins are great for drawing heat out of things they are in contact with. They are useless in cooling things that they are not in contact with - any tiny airgap renders them nearly useless. This is why there is often conductive grease under them in electronic applications - to eliminate any possible airgap. If I understand correctly, much of the heat in motors builds up in the windings. Since this is part of the rotor, which is in the middle of the motor and surrounded by an airgap, I'm not sure how effective external fins would be in cooling that hottest part of the motor.<br />
<br />
What I'd think would work better is a "slinger fan" on the motor shaft, inside the grinder housing. This draws air over the motor, through the middle of the motor, and basically sucks heat out of the motor shaft. I imagine there are some grinders that use this fairly common part to keep it cool, but I haven't run across one yet. Large mass aluminum body comp…tag:www.baristaexchange.com,2009-10-31:1688216:Comment:6739362009-10-31T20:21:34.967ZJeremy Conleyhttps://www.baristaexchange.com/profile/JeremyConley
Large mass aluminum body components, essentially the bulk of the casing, could be used as heat sinks+fin ventilation to draw away heat before it had a chance to become substantial. It's an interesting idea. I agree that once you reach a point where the heat is a problem, direct drive equals direct heat transfer; but with good proactive heat management, we'd have to be talking about some crazy high volume.<br />
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<cite>Brady said:…</cite>
Large mass aluminum body components, essentially the bulk of the casing, could be used as heat sinks+fin ventilation to draw away heat before it had a chance to become substantial. It's an interesting idea. I agree that once you reach a point where the heat is a problem, direct drive equals direct heat transfer; but with good proactive heat management, we'd have to be talking about some crazy high volume.<br />
<br />
<cite>Brady said:</cite><blockquote cite="http://baristaexchange.ning.com/forum/topics/flat-vs-conical-in-a-slightly#1688216Comment673909"><div>I've not done any experiments, though sounds like a great reason to justify purchasing an IR thermometer :)<br/> <br/>
As I understand, the heat generated by the burrs is due to friction from the burnishing action... so sharp burrs run cooler than dull burrs. So assuming burrs are appropriately sharp, slower turning = lower heat generated = lower temperatures. You are correct, though... if heat produced is equal, larger mass = lower temperature, heating up slower but staying at that temperature longer.<br/>
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The motor discussion is interesting. Jeremy, you are correct that isolation and fins are cheaper than active cooling. The thing to remember with fins though is that they transfer heat by conduction... so they need to be in contact with the hot part to function. This makes them ineffective in cooling the rotor of the motor. Also, since the grinding burrs are attached to the steel motor shaft, heat in the rotor will be conducted right up to the burrs, regardless of how much insulation there is between the motor itself and the grinding chambers.<br/>
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The benefit of fan-cooling is that it can remove heat from the hot rotor before it conducts up to the burrs. The other benefit is that you can modify an existing grinder to add a cooling fan... a little harder to add fins.</div>
</blockquote> I've not done any experiments…tag:www.baristaexchange.com,2009-10-31:1688216:Comment:6739092009-10-31T19:50:46.210ZBradyhttps://www.baristaexchange.com/profile/Brady
I've not done any experiments, though sounds like a great reason to justify purchasing an IR thermometer :)<br />
<br />
As I understand, the heat generated by the burrs is due to friction from the burnishing action... so sharp burrs run cooler than dull burrs. So assuming burrs are appropriately sharp, slower turning = lower heat generated = lower temperatures. You are correct, though... if heat produced is equal, larger mass = lower temperature, heating up slower but staying at that temperature…
I've not done any experiments, though sounds like a great reason to justify purchasing an IR thermometer :)<br />
<br />
As I understand, the heat generated by the burrs is due to friction from the burnishing action... so sharp burrs run cooler than dull burrs. So assuming burrs are appropriately sharp, slower turning = lower heat generated = lower temperatures. You are correct, though... if heat produced is equal, larger mass = lower temperature, heating up slower but staying at that temperature longer.<br />
<br />
The motor discussion is interesting. Jeremy, you are correct that isolation and fins are cheaper than active cooling. The thing to remember with fins though is that they transfer heat by conduction... so they need to be in contact with the hot part to function. This makes them ineffective in cooling the rotor of the motor. Also, since the grinding burrs are attached to the steel motor shaft, heat in the rotor will be conducted right up to the burrs, regardless of how much insulation there is between the motor itself and the grinding chambers.<br />
<br />
The benefit of fan-cooling is that it can remove heat from the hot rotor before it conducts up to the burrs. The other benefit is that you can modify an existing grinder to add a cooling fan... a little harder to add fins. You would think that dual-wal…tag:www.baristaexchange.com,2009-10-31:1688216:Comment:6733202009-10-31T03:00:34.866ZJeremy Conleyhttps://www.baristaexchange.com/profile/JeremyConley
You would think that dual-wall insolation/isolation+heatsinking would be a simple solution to managing the heat amassed and retained by the larger motors. Seems more proactive and less expensive than active cooling.
You would think that dual-wall insolation/isolation+heatsinking would be a simple solution to managing the heat amassed and retained by the larger motors. Seems more proactive and less expensive than active cooling. mark koncz said:...remember!,…tag:www.baristaexchange.com,2009-10-30:1688216:Comment:6730642009-10-30T21:39:10.029ZMike McGinnesshttps://www.baristaexchange.com/profile/miKemcKoffeeakaMikeMcGinness
<cite>mark koncz said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/flat-vs-conical-in-a-slightly#1688216Comment671941"><div>...remember!, the motor also transfer heat, not just the friction.<br></br></div>
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I recall discussions and testing that concluded the motor is the <b>major</b> culprit of the heating. The higher powered slower turning electric motors of the big conical burr grinders heat slower and hence the advantage realized, but not so much from the…
<cite>mark koncz said:</cite><blockquote cite="http://www.baristaexchange.com/forum/topics/flat-vs-conical-in-a-slightly#1688216Comment671941"><div>...remember!, the motor also transfer heat, not just the friction.<br/></div>
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I recall discussions and testing that concluded the motor is the <b>major</b> culprit of the heating. The higher powered slower turning electric motors of the big conical burr grinders heat slower and hence the advantage realized, but not so much from the burrs versus flat but the motor dynamics. A smaller powered motor required to do the same amount of work (grind X shots) will heat much faster than larger. But, once heated the larger mass motors takes longer to cool and can become a disadvantage, hence active cooling (vented and even internal fans).