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Date: 19 Feb 2007 18:43:52
From: Jonathan Thiessen
Subject: Home roasting thoughts
Salutations,

I was thinking, and I've come up with an idea. Whether it's a good [or
original] idea, or not, I'm not sure. The plan is to use a portable
induction cooktop with... a pot. The idea is also to have an overhead
electric motor driving a mixing blade, and also to run the cooktop
through a variac which is magically controlled by a fancy temperature
controller like the nice Fuji ones. One of the very nice things about
induction cooktops is that they are rather responsive [much like gas
burners]. In my thinking though, this sort of responsiveness doesn't
mean much if it can't be controlled smoothly [analogue-like, or at least
multi-step]. I've never actually used an induction cooktop before, but
we have a halogen one, and the most annoying aspect of it is that the
different temp settings are realized by it turning off, and on
occasionally which yields a most inconsistent/erratic temp that is
useless for cooking anything but water. I wouldn't want the same sort of
issue with my coffee roasting apparatus. But maybe I'm off on this one
**shrugs**.

My concerns are:
1. Running an electric motor close to an induction cooktop. Is this a
problem? [Both being magnetic devices, and all]
2. Are there temp controllers that are "analogue", or are they all
"digital" in design? That is to say, will they output at a constant
voltage, or off; or can they output smoothly over a range [Lets say
you're ramping up, but going to fast. Instead of letting it go until
it's over temp, it should give a decrease in voltage signaling that the
heater should give a reduced output, and thus avoiding overshooting, and
undershooting]. Should I even be concerned with this? Will it make a
difference? Am I better off to just control a relay with the temp
controller, rather than bothering with smooth temp transition?
3. Are there variacs that can be controlled via some control voltage. In
other words, can we somehow scale the control voltage output from the
temp controller up to the 0-120VAC sort of range.
4. Is it ok/safe to run induction cooktops at a reduced voltage? Should
I look for a purely analogue cooktop so that I can set it full-bore, and
let the variac do it's thing? [That is, will running a digitally
controlled unit on a variac screw it up?].
5. Is this all-round just a really bad idea? I mean... I really quite
like it conceptually so long as it's possible, and [economically]
feasible. What are your thoughts?

Thank you for your time.
Have a good one ;)
//jonathan




 
Date: 22 Feb 2007 10:59:28
From:
Subject: Re: Home roasting thoughts
I've been overly-sensitive ever since celebrating Washington's
birthday on some day other than the 22nd.

# : o )
tin

On Feb 21, 4:34 pm, "Ed Needham" <e...@NOSPAMhomeroaster.com > wrote:
> tin, you and I have both posted together on alt.coffee and other lists
> over the years, and I highly regard your inventive and creative skills. =
On
> alt.coffee I have never gotten into any of the shenanigans that many have,
> with slurs, name calling and outright insults. I try 'once' to get just a
> little bit feisty and now I'm in trouble.
> Just give me this one jab, please :::::grin::::::.
> Go ahead, call me a bean head or something so we can be even.
> --
> *********************
> Ed Needham=AE
> "to absurdity and beyond!"http://www.homeroaster.com
> (include [FRIEND] in subject line to get through my SPAM filters)
> *********************
>
> <coffeeem...@gmail.com> wrote in message
>
> news:1172036614.947980.107230@q2g2000cwa.googlegroups.com...
> Fair enough. Nothing here to argue with. But it's quite a jump to
> characterize my "personal criteria" (either generally or specifically)
> as "rules [that] need to be followed stringently" and "grunting
> through a list of rules." IMO, one doesn't have to choose between the
> criteria that I stated and giving full reign to inspiration or
> invention. Rules may get in the way of invention, but knowledge
> generally doesn't.
>
> tin (Heat + beans =3D roast. All the rest is commentary)
>
> On Feb 20, 8:17 pm, "Ed Needham" <e...@NOSPAMhomeroaster.com> wrote:
>
> > My reply was not an insult but rather a commentary.
>
> > I've found that rules just get in the way of invention. Maybe at a
> > corporate level rules need to be followed stringently, but as a small,
> > home
> > inventor, rules impede progress. I've had several firsts and they have
> > all
> > come from inspiration rather than grunting through a list of rules to
> > follow. Generally they have been given birth by breaking established
> > rules
> > or going places where rules have not been devised.
>
> > Thomas Edison once said,
> > "Hell, there are no rules here-- we're trying to accomplish something."
>
> > I think he was on to something.
> > --
> > *********************
> > Ed Needham=AE
> > "to absurdity and beyond!"http://www.homeroaster.com
> > (include [FRIEND] in subject line to get through my SPAM filters)
> > *********************
>
> > <coffeeem...@gmail.com> wrote in message
>
> >news:1172025742.438605.11650@j27g2000cwj.googlegroups.com...
>
> > > Ah, the oft-used Needham "(g)." Meaning, "insult intended."
>
> > > I don't make procedures for the government, but I don't categorically
> > > reject fiscal, safety, and performance criteria even if they originate
> > > from the the govt. Likewise, I don't valorize franken-roasters
> > > unless they actually accomplish something that's more parsimonious
> > > than a Hottop, dogbowl, variac'd popper, etc. So I offered my
> > > "personal criteria" along with the caveat of "it's worth trying
> > > anything on little more than a hunch" (which seemed only fitting
> > > coming from someone who stumbled onto HG/DB roasting barely before he
> > > knew which end of the bean was up).
>
> > > So are there any of the criteria that you disagree with? Any others
> > > that you'd offer?
> > > (f)




 
Date: 20 Feb 2007 21:43:35
From:
Subject: Re: Home roasting thoughts
Fair enough. Nothing here to argue with. But it's quite a jump to
characterize my "personal criteria" (either generally or specifically)
as "rules [that] need to be followed stringently" and "grunting
through a list of rules." IMO, one doesn't have to choose between the
criteria that I stated and giving full reign to inspiration or
invention. Rules may get in the way of invention, but knowledge
generally doesn't.

tin (Heat + beans =3D roast. All the rest is commentary)


On Feb 20, 8:17 pm, "Ed Needham" <e...@NOSPAMhomeroaster.com > wrote:
> My reply was not an insult but rather a commentary.
>
> I've found that rules just get in the way of invention. Maybe at a
> corporate level rules need to be followed stringently, but as a small, ho=
me
> inventor, rules impede progress. I've had several firsts and they have a=
ll
> come from inspiration rather than grunting through a list of rules to
> follow. Generally they have been given birth by breaking established ru=
les
> or going places where rules have not been devised.
>
> Thomas Edison once said,
> "Hell, there are no rules here-- we're trying to accomplish something."
>
> I think he was on to something.
> --
> *********************
> Ed Needham=AE
> "to absurdity and beyond!"http://www.homeroaster.com
> (include [FRIEND] in subject line to get through my SPAM filters)
> *********************
>
> <coffeeem...@gmail.com> wrote in message
>
> news:1172025742.438605.11650@j27g2000cwj.googlegroups.com...
>
> > Ah, the oft-used Needham "(g)." Meaning, "insult intended."
>
> > I don't make procedures for the government, but I don't categorically
> > reject fiscal, safety, and performance criteria even if they originate
> > from the the govt. Likewise, I don't valorize franken-roasters
> > unless they actually accomplish something that's more parsimonious
> > than a Hottop, dogbowl, variac'd popper, etc. So I offered my
> > "personal criteria" along with the caveat of "it's worth trying
> > anything on little more than a hunch" (which seemed only fitting
> > coming from someone who stumbled onto HG/DB roasting barely before he
> > knew which end of the bean was up).
>
> > So are there any of the criteria that you disagree with? Any others
> > that you'd offer?
> > (f)






  
Date: 21 Feb 2007 19:34:54
From: Ed Needham
Subject: Re: Home roasting thoughts
tin, you and I have both posted together on alt.coffee and other lists
over the years, and I highly regard your inventive and creative skills. On
alt.coffee I have never gotten into any of the shenanigans that many have,
with slurs, name calling and outright insults. I try 'once' to get just a
little bit feisty and now I'm in trouble.
Just give me this one jab, please :::::grin::::::.
Go ahead, call me a bean head or something so we can be even.
--
*********************
Ed Needham®
"to absurdity and beyond!"
http://www.homeroaster.com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************

<coffeeemail@gmail.com > wrote in message
news:1172036614.947980.107230@q2g2000cwa.googlegroups.com...
Fair enough. Nothing here to argue with. But it's quite a jump to
characterize my "personal criteria" (either generally or specifically)
as "rules [that] need to be followed stringently" and "grunting
through a list of rules." IMO, one doesn't have to choose between the
criteria that I stated and giving full reign to inspiration or
invention. Rules may get in the way of invention, but knowledge
generally doesn't.

tin (Heat + beans = roast. All the rest is commentary)


On Feb 20, 8:17 pm, "Ed Needham" <e...@NOSPAMhomeroaster.com > wrote:
> My reply was not an insult but rather a commentary.
>
> I've found that rules just get in the way of invention. Maybe at a
> corporate level rules need to be followed stringently, but as a small,
> home
> inventor, rules impede progress. I've had several firsts and they have
> all
> come from inspiration rather than grunting through a list of rules to
> follow. Generally they have been given birth by breaking established
> rules
> or going places where rules have not been devised.
>
> Thomas Edison once said,
> "Hell, there are no rules here-- we're trying to accomplish something."
>
> I think he was on to something.
> --
> *********************
> Ed Needham®
> "to absurdity and beyond!"http://www.homeroaster.com
> (include [FRIEND] in subject line to get through my SPAM filters)
> *********************
>
> <coffeeem...@gmail.com> wrote in message
>
> news:1172025742.438605.11650@j27g2000cwj.googlegroups.com...
>
> > Ah, the oft-used Needham "(g)." Meaning, "insult intended."
>
> > I don't make procedures for the government, but I don't categorically
> > reject fiscal, safety, and performance criteria even if they originate
> > from the the govt. Likewise, I don't valorize franken-roasters
> > unless they actually accomplish something that's more parsimonious
> > than a Hottop, dogbowl, variac'd popper, etc. So I offered my
> > "personal criteria" along with the caveat of "it's worth trying
> > anything on little more than a hunch" (which seemed only fitting
> > coming from someone who stumbled onto HG/DB roasting barely before he
> > knew which end of the bean was up).
>
> > So are there any of the criteria that you disagree with? Any others
> > that you'd offer?
> > (f)







 
Date: 20 Feb 2007 20:53:50
From: rasqual
Subject: Re: Home roasting thoughts
On Feb 20, 3:19 pm, Jonathan Thiessen
<jjthies...@student.math.uwaterloo.ca > wrote:
> Oh yeah... I forgot to say, [with respect to the espresso machine] if
> one is going to control the piston via some on device controller, or a
> standalone computer, you might as well have precise control over the
> brewing temps too since water is heated on a per shot basis.

What follows is NOT a mindless lampoon.

How about using a variation on MRI scanning to measure the water
temperature EXTREMELY precisely? What's great is that it would allow
for measuring the amount of heat present in the entire water volume,
rather than counting on some geographic locus of median reliability on
the surface of something.

Perhaps the best thing would be to contrive an analog method --
perhaps using Nitinol valves -- of automatically controlling
backpressure to regulate thermal transfer to a flowing volume of
water. Envision a showerhead with each of hundreds of small holes
being heated and controlled independently, easily within a tenth of a
degree. Each orifice would be an instance of nanotech in action.

In a bizarre sense, I'm advocating reliance on high tech to implement
utter low-tech -- precise analog regulation, rather than positive
control in a digital sense. In some sense, I'm advocating the nano
equivalent of the centrifugal governors on old steam engines. ;-)

Like I said, not mindless lampoon. Someone just told me, "show them
you're nuts," so I did. ;-)

- Scott



  
Date: 21 Feb 2007 02:16:53
From: Jonathan Thiessen
Subject: Re: Home roasting thoughts
Good stuff :) If I ever need ideas I now know who to come to :P But
yeah, seriously, I believe that my espresso machine idea would make for
an awesome reference machine -- not at all practical, but who cares? It
really would be industrial/lab equipment. Nothing quite like it that I
know of anyway *-) Who knows, maybe it truly is/will be practical
**shrugs** I'll make sure to tell you guys when I'm done :P

rasqual wrote:
> On Feb 20, 3:19 pm, Jonathan Thiessen
> <jjthies...@student.math.uwaterloo.ca> wrote:
>> Oh yeah... I forgot to say, [with respect to the espresso machine] if
>> one is going to control the piston via some on device controller, or a
>> standalone computer, you might as well have precise control over the
>> brewing temps too since water is heated on a per shot basis.
>
> What follows is NOT a mindless lampoon.
>
> How about using a variation on MRI scanning to measure the water
> temperature EXTREMELY precisely? What's great is that it would allow
> for measuring the amount of heat present in the entire water volume,
> rather than counting on some geographic locus of median reliability on
> the surface of something.
>
> Perhaps the best thing would be to contrive an analog method --
> perhaps using Nitinol valves -- of automatically controlling
> backpressure to regulate thermal transfer to a flowing volume of
> water. Envision a showerhead with each of hundreds of small holes
> being heated and controlled independently, easily within a tenth of a
> degree. Each orifice would be an instance of nanotech in action.
>
> In a bizarre sense, I'm advocating reliance on high tech to implement
> utter low-tech -- precise analog regulation, rather than positive
> control in a digital sense. In some sense, I'm advocating the nano
> equivalent of the centrifugal governors on old steam engines. ;-)
>
> Like I said, not mindless lampoon. Someone just told me, "show them
> you're nuts," so I did. ;-)
>
> - Scott
>


  
Date: 20 Feb 2007 21:45:46
From: Johnny
Subject: Re: Home roasting thoughts

"rasqual" <scott.quardt@gmail.com > wrote in message
news:1172033630.545792.35080@v45g2000cwv.googlegroups.com...
> On Feb 20, 3:19 pm, Jonathan Thiessen
> <jjthies...@student.math.uwaterloo.ca> wrote:
> > Oh yeah... I forgot to say, [with respect to the espresso machine] if
> > one is going to control the piston via some on device controller, or a
> > standalone computer, you might as well have precise control over the
> > brewing temps too since water is heated on a per shot basis.
>
> What follows is NOT a mindless lampoon.
>
> How about using a variation on MRI scanning to measure the water
> temperature EXTREMELY precisely? What's great is that it would allow
> for measuring the amount of heat present in the entire water volume,
> rather than counting on some geographic locus of median reliability on
> the surface of something.

isn't that the way a pressure sensor works? averaging out the pressure based
on the overall heat present.





   
Date: 21 Feb 2007 02:01:44
From: Jonathan Thiessen
Subject: Re: Home roasting thoughts
Pressure sensors should work on the basis of force measurement of some
sort, me thinks [ie a spring [at least in the case of old-school
gauges]]. I personally don't know of other methods, but of course, I'm
not entirely infallible :P As long as you don't need your gauges/sensors
anywhere near as fast/responsive as the speed of sound in whatever fluid
you're measuring the pressure of; or, you need the pressure at various
depths [which you could actually calc by hand using only one reference
pressure], you should be ok with just one gauge/sensor. Pressure really
is just force averaged over an area. I could be misunderstanding what
you're saying though. Given the right restraints on your system, you
could indirectly calculate the pressure of your system as a function of
internal energy, or something like that, but it'd be pretty tech. Of
course, if we're going to use an MRI somehow, we might as well.

Johnny wrote:
> "rasqual" <scott.quardt@gmail.com> wrote in message
> news:1172033630.545792.35080@v45g2000cwv.googlegroups.com...
>> On Feb 20, 3:19 pm, Jonathan Thiessen
>> <jjthies...@student.math.uwaterloo.ca> wrote:
>>> Oh yeah... I forgot to say, [with respect to the espresso machine] if
>>> one is going to control the piston via some on device controller, or a
>>> standalone computer, you might as well have precise control over the
>>> brewing temps too since water is heated on a per shot basis.
>> What follows is NOT a mindless lampoon.
>>
>> How about using a variation on MRI scanning to measure the water
>> temperature EXTREMELY precisely? What's great is that it would allow
>> for measuring the amount of heat present in the entire water volume,
>> rather than counting on some geographic locus of median reliability on
>> the surface of something.
>
> isn't that the way a pressure sensor works? averaging out the pressure based
> on the overall heat present.
>
>
>


 
Date: 20 Feb 2007 18:42:22
From:
Subject: Re: Home roasting thoughts
Ah, the oft-used Needham "(g)." Meaning, "insult intended."

I don't make procedures for the government, but I don't categorically
reject fiscal, safety, and performance criteria even if they originate
from the the govt. Likewise, I don't valorize franken-roasters
unless they actually accomplish something that's more parsimonious
than a Hottop, dogbowl, variac'd popper, etc. So I offered my
"personal criteria" along with the caveat of "it's worth trying
anything on little more than a hunch" (which seemed only fitting
coming from someone who stumbled onto HG/DB roasting barely before he
knew which end of the bean was up).

So are there any of the criteria that you disagree with? Any others
that you'd offer?
(f)

On Feb 20, 4:23 pm, "Ed Needham" <e...@NOSPAMhomeroaster.com > wrote:
> You work for the government policies and procedures office, right?
> (g)
>
> <coffeeem...@gmail.com> wrote in message
>
> news:1171993409.710749.112250@h3g2000cwc.googlegroups.com...
>
> > For starters, here are some personal criteria I'd have to satisfy
> > before embartking on complex invention. Not inclusive or necessarily
> > the order of importance:
> > 1. I'd have to be an excellent and experienced cupper. Not just I-
> > know-what-I-like, but having a wide range of controlled and confirmed
> > experience. Otherwise, how could I trust any of my findings along the
> > way? How could I sensibly draw from the experiences of a far-flung
> > community of other experts?
> > 2. I'd have to know what particular aspects of current technology I
> > want to improve upon. This would require some experience with a
> > variety of current roasting methods. Simply demonstrating that I
> > could make a decent roast happen would not not be enough. I'd want to
> > target a batch size range; not build the unit and then see how much it
> > could roast. OTOH, if the materials and assembly were handy and cheap,
> > it's worth trying anything on little more than a hunch.
> > 3. Convenient strorage, aestheticly pleasing, and robustly built
> > should not be afterthoughts, but considerations from the very
> > begining. These account for much of the cost of off-the-shelf quality
> > roasters. So is the goal to build a cheaper Hottop or Probat with the
> > minor inconveniences of a tangle of exposed wires, corners that singe
> > and rip flesh, tripped breakers, and which you operate from the floor
> > of an unheated garage?
> > tin




  
Date: 20 Feb 2007 23:17:51
From: Ed Needham
Subject: Re: Home roasting thoughts
My reply was not an insult but rather a commentary.

I've found that rules just get in the way of invention. Maybe at a
corporate level rules need to be followed stringently, but as a small, home
inventor, rules impede progress. I've had several firsts and they have all
come from inspiration rather than grunting through a list of rules to
follow. Generally they have been given birth by breaking established rules
or going places where rules have not been devised.

Thomas Edison once said,
"Hell, there are no rules here-- we're trying to accomplish something."

I think he was on to something.
--
*********************
Ed Needham®
"to absurdity and beyond!"
http://www.homeroaster.com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************

<coffeeemail@gmail.com > wrote in message
news:1172025742.438605.11650@j27g2000cwj.googlegroups.com...
> Ah, the oft-used Needham "(g)." Meaning, "insult intended."
>
> I don't make procedures for the government, but I don't categorically
> reject fiscal, safety, and performance criteria even if they originate
> from the the govt. Likewise, I don't valorize franken-roasters
> unless they actually accomplish something that's more parsimonious
> than a Hottop, dogbowl, variac'd popper, etc. So I offered my
> "personal criteria" along with the caveat of "it's worth trying
> anything on little more than a hunch" (which seemed only fitting
> coming from someone who stumbled onto HG/DB roasting barely before he
> knew which end of the bean was up).
>
> So are there any of the criteria that you disagree with? Any others
> that you'd offer?
> (f)




  
Date: 20 Feb 2007 23:11:03
From: Ed Needham
Subject: Re: Home roasting thoughts
I've found that rules just get in the way of invention. Maybe at a
corporate level rules need to be followed stringently, but as a small, home
inventor, rules just get in the way.
I've had several firsts and they have all come from inspiration rather than
grunting through
a list of rules to follow. Generally they have been given birth by breaking
established rules or going places where rules have not been devised. Thomas
Edison once said, "Hell, there are no rules here-- we're trying to
accomplish something."
I think he was on to something.
--
*********************
Ed Needham®
"to absurdity and beyond!"
http://www.homeroaster.com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************

<coffeeemail@gmail.com > wrote in message
news:1172025742.438605.11650@j27g2000cwj.googlegroups.com...
> Ah, the oft-used Needham "(g)." Meaning, "insult intended."
>
> I don't make procedures for the government, but I don't categorically
> reject fiscal, safety, and performance criteria even if they originate
> from the the govt. Likewise, I don't valorize franken-roasters
> unless they actually accomplish something that's more parsimonious
> than a Hottop, dogbowl, variac'd popper, etc. So I offered my
> "personal criteria" along with the caveat of "it's worth trying
> anything on little more than a hunch" (which seemed only fitting
> coming from someone who stumbled onto HG/DB roasting barely before he
> knew which end of the bean was up).
>
> So are there any of the criteria that you disagree with? Any others
> that you'd offer?
> (f)
>
> On Feb 20, 4:23 pm, "Ed Needham" <e...@NOSPAMhomeroaster.com> wrote:
>> You work for the government policies and procedures office, right?
>> (g)





 
Date: 20 Feb 2007 09:51:48
From: Calvin
Subject: Re: Home roasting thoughts
On Feb 19, 5:43 pm, Jonathan Thiessen
<jjthies...@student.math.uwaterloo.ca > wrote:
> Salutations,
>
> I was thinking, and I've come up with an idea. Whether it's a good [or
> original] idea, or not, I'm not sure. The plan is to use a portable
> induction cooktop with... a pot. The idea is also to have an overhead
> electric motor driving a mixing blade, and also to run the cooktop
> through a variac which is magically controlled by a fancy temperature
> controller like the nice Fuji ones. One of the very nice things about
> induction cooktops is that they are rather responsive [much like gas
> burners]. In my thinking though, this sort of responsiveness doesn't
> mean much if it can't be controlled smoothly [analogue-like, or at least
> multi-step]. I've never actually used an induction cooktop before, but
> we have a halogen one, and the most annoying aspect of it is that the
> different temp settings are realized by it turning off, and on
> occasionally which yields a most inconsistent/erratic temp that is
> useless for cooking anything but water. I wouldn't want the same sort of
> issue with my coffee roasting apparatus. But maybe I'm off on this one
> **shrugs**.
>
> My concerns are:
> 1. Running an electric motor close to an induction cooktop. Is this a
> problem? [Both being magnetic devices, and all]
> 2. Are there temp controllers that are "analogue", or are they all
> "digital" in design? That is to say, will they output at a constant
> voltage, or off; or can they output smoothly over a range [Lets say
> you're ramping up, but going to fast. Instead of letting it go until
> it's over temp, it should give a decrease in voltage signaling that the
> heater should give a reduced output, and thus avoiding overshooting, and
> undershooting]. Should I even be concerned with this? Will it make a
> difference? Am I better off to just control a relay with the temp
> controller, rather than bothering with smooth temp transition?
> 3. Are there variacs that can be controlled via some control voltage. In
> other words, can we somehow scale the control voltage output from the
> temp controller up to the 0-120VAC sort of range.
> 4. Is it ok/safe to run induction cooktops at a reduced voltage? Should
> I look for a purely analogue cooktop so that I can set it full-bore, and
> let the variac do it's thing? [That is, will running a digitally
> controlled unit on a variac screw it up?].
> 5. Is this all-round just a really bad idea? I mean... I really quite
> like it conceptually so long as it's possible, and [economically]
> feasible. What are your thoughts?
>
> Thank you for your time.
> Have a good one ;)
> //jonathan

I don't know if an inductive cooktop can be run duty cycle and if you
will be able to find an SSR that will put up with the abuse. It would
definitely be cheaper and easier to use a resistive element like the
standalone ones you can get for $15 at any department store. To go
the variac route you would need to build a coupling and mount for a
servo motor and then build your own temp sensor and PID to drive it;
stock PIDs can read a thermocouple and drive an SSR already.

It sounds like you are trying to build an automated pan-roaster. I
have my doubts that a PID would ever be able to manage such a chaotic
and massive system. You would probably need to sample over such a
large time frame - tens of seconds - and react so slowly that you
would not have the fine control that you are pursuing in the first
place. It's a long trip from the range to the bean mass.

>From my experience in pan roasting the most important factor is bean
movement. You MUST keep the beans in motion in both dimensions. You
ability to roast in a controlled way will be a result of finding the
right balance between heat transfer from the pot (surface area),
charge size (total mass to heat), and stirring (getting that heat into
all surfaces of all the beans the same).

Good luck and don't let the nay-sayers like me keep you from
experimenting.



  
Date: 20 Feb 2007 16:05:37
From: Jonathan Thiessen
Subject: Re: Home roasting thoughts
I'm not sure if I'll actually get to experimenting for a couple months
yet [when I get back home for the summer], so for right now I'm just
trying to toss some ideas around [Both in my head, and out to people
with better roasting and electrical/PID experience]. My original thought
was that a drum would be better, but I like the idea of inductive
cooking [roasting in this case], and I couldn't really think of anyway
of keeping with both. In my thinking, gas/propane really would be the
best method, however, sort of that, I would think it best to make the
heating as direct as possible so as to avoid the issues of thermal mass
affecting control [inductive, light, microwave?]. One issue with
microwave is that it excites water [any moisture?] within, rather than
being radiant [heat wise].

Which reminds me... I also have an idea for an espresso machine, and I
think it'd be awesome if ever I did actually pursue it [maybe one of
these days when I'm back at home :)]. But yeah... The idea is to make
the machine as thermally insulated/non-conducting as possible, and to
dose water into a chamber [expressly for you :P] where it is heated
using microwaves, and then forced through the coffee puck by a PLC'd
hydraulic piston. I believe this would lead to the ultimate extraction
given the instant on/instant off thermal stability, and controllable
[read smooth rampable] flow rate/pressure. It would be a _relatively_
simple design, and it would offer all the advantages of a piston/lever
machine, but it would be completely controllable/consistent/ever
predictable. The only possible disadvantage that I can think of is maybe
cost [And I suppose that if you really want to make milk beverages, then
you'll have to look elsewhere to steam/froth... Oh, and I suppose it
would take a bit longer to make a shot given that water is heated on a
per shot basis [Although the nice thing is that idle draw - >0W], so make
that three disadvantages].


Calvin wrote:
> On Feb 19, 5:43 pm, Jonathan Thiessen
> <jjthies...@student.math.uwaterloo.ca> wrote:
>> Salutations,
>>
>> I was thinking, and I've come up with an idea. Whether it's a good [or
>> original] idea, or not, I'm not sure. The plan is to use a portable
>> induction cooktop with... a pot. The idea is also to have an overhead
>> electric motor driving a mixing blade, and also to run the cooktop
>> through a variac which is magically controlled by a fancy temperature
>> controller like the nice Fuji ones. One of the very nice things about
>> induction cooktops is that they are rather responsive [much like gas
>> burners]. In my thinking though, this sort of responsiveness doesn't
>> mean much if it can't be controlled smoothly [analogue-like, or at least
>> multi-step]. I've never actually used an induction cooktop before, but
>> we have a halogen one, and the most annoying aspect of it is that the
>> different temp settings are realized by it turning off, and on
>> occasionally which yields a most inconsistent/erratic temp that is
>> useless for cooking anything but water. I wouldn't want the same sort of
>> issue with my coffee roasting apparatus. But maybe I'm off on this one
>> **shrugs**.
>>
>> My concerns are:
>> 1. Running an electric motor close to an induction cooktop. Is this a
>> problem? [Both being magnetic devices, and all]
>> 2. Are there temp controllers that are "analogue", or are they all
>> "digital" in design? That is to say, will they output at a constant
>> voltage, or off; or can they output smoothly over a range [Lets say
>> you're ramping up, but going to fast. Instead of letting it go until
>> it's over temp, it should give a decrease in voltage signaling that the
>> heater should give a reduced output, and thus avoiding overshooting, and
>> undershooting]. Should I even be concerned with this? Will it make a
>> difference? Am I better off to just control a relay with the temp
>> controller, rather than bothering with smooth temp transition?
>> 3. Are there variacs that can be controlled via some control voltage. In
>> other words, can we somehow scale the control voltage output from the
>> temp controller up to the 0-120VAC sort of range.
>> 4. Is it ok/safe to run induction cooktops at a reduced voltage? Should
>> I look for a purely analogue cooktop so that I can set it full-bore, and
>> let the variac do it's thing? [That is, will running a digitally
>> controlled unit on a variac screw it up?].
>> 5. Is this all-round just a really bad idea? I mean... I really quite
>> like it conceptually so long as it's possible, and [economically]
>> feasible. What are your thoughts?
>>
>> Thank you for your time.
>> Have a good one ;)
>> //jonathan
>
> I don't know if an inductive cooktop can be run duty cycle and if you
> will be able to find an SSR that will put up with the abuse. It would
> definitely be cheaper and easier to use a resistive element like the
> standalone ones you can get for $15 at any department store. To go
> the variac route you would need to build a coupling and mount for a
> servo motor and then build your own temp sensor and PID to drive it;
> stock PIDs can read a thermocouple and drive an SSR already.
>
> It sounds like you are trying to build an automated pan-roaster. I
> have my doubts that a PID would ever be able to manage such a chaotic
> and massive system. You would probably need to sample over such a
> large time frame - tens of seconds - and react so slowly that you
> would not have the fine control that you are pursuing in the first
> place. It's a long trip from the range to the bean mass.
>
>>From my experience in pan roasting the most important factor is bean
> movement. You MUST keep the beans in motion in both dimensions. You
> ability to roast in a controlled way will be a result of finding the
> right balance between heat transfer from the pot (surface area),
> charge size (total mass to heat), and stirring (getting that heat into
> all surfaces of all the beans the same).
>
> Good luck and don't let the nay-sayers like me keep you from
> experimenting.
>


   
Date: 20 Feb 2007 21:43:00
From: Johnny
Subject: Re: Home roasting thoughts

"Jonathan Thiessen" <jjthiessen@student.math.uwaterloo.ca > wrote in message
news:erfnr1$l1v$1@rumours.uwaterloo.ca...
> I'm not sure if I'll actually get to experimenting for a couple months
> yet [when I get back home for the summer], so for right now I'm just
> trying to toss some ideas around [Both in my head, and out to people
> with better roasting and electrical/PID experience]. My original thought
> was that a drum would be better, but I like the idea of inductive
> cooking [roasting in this case], <snip/>

don't spose there's a way to heat the drum inductively is there? I guess
it's too big...




    
Date: 21 Feb 2007 02:08:42
From: Jonathan Thiessen
Subject: Re: Home roasting thoughts
I'm not actually to sure on how it all works other than it uses magnetic
induction. The reasoning was to lessen the thermal mass, and thus have a
more responsive system. I think it would require encasing the drum in
the inductive-cooktop-surface-stuff which sounds rather custom and
expensive to me **shrugs** Very well might be possible, but yeah... I dunno.

Johnny wrote:
> "Jonathan Thiessen" <jjthiessen@student.math.uwaterloo.ca> wrote in message
> news:erfnr1$l1v$1@rumours.uwaterloo.ca...
>> I'm not sure if I'll actually get to experimenting for a couple months
>> yet [when I get back home for the summer], so for right now I'm just
>> trying to toss some ideas around [Both in my head, and out to people
>> with better roasting and electrical/PID experience]. My original thought
>> was that a drum would be better, but I like the idea of inductive
>> cooking [roasting in this case], <snip/>
>
> don't spose there's a way to heat the drum inductively is there? I guess
> it's too big...
>
>


   
Date: 20 Feb 2007 16:19:08
From: Jonathan Thiessen
Subject: Re: Home roasting thoughts
Oh yeah... I forgot to say, [with respect to the espresso machine] if
one is going to control the piston via some on device controller, or a
standalone computer, you might as well have precise control over the
brewing temps too since water is heated on a per shot basis. This would
definitely be handy if, say, you perfected your shot pulling, and then
you went to barista competitions in both Death Valley, and on Everest ;)
[I think it'd be neat at least if not practical]. Even if it wasn't
really a production machine, it'd be a good machine for espresso
research... I'll have to see if I can get an NSERC grant for that...
seriously :)


Jonathan Thiessen wrote:
> I'm not sure if I'll actually get to experimenting for a couple
> months yet [when I get back home for the summer], so for right now I'm
> just trying to toss some ideas around [Both in my head, and out to
> people with better roasting and electrical/PID experience]. My original
> thought was that a drum would be better, but I like the idea of
> inductive cooking [roasting in this case], and I couldn't really think
> of anyway of keeping with both. In my thinking, gas/propane really would
> be the best method, however, sort of that, I would think it best to make
> the heating as direct as possible so as to avoid the issues of thermal
> mass affecting control [inductive, light, microwave?]. One issue with
> microwave is that it excites water [any moisture?] within, rather than
> being radiant [heat wise].
>
> Which reminds me... I also have an idea for an espresso machine, and
> I think it'd be awesome if ever I did actually pursue it [maybe one of
> these days when I'm back at home :)]. But yeah... The idea is to make
> the machine as thermally insulated/non-conducting as possible, and to
> dose water into a chamber [expressly for you :P] where it is heated
> using microwaves, and then forced through the coffee puck by a PLC'd
> hydraulic piston. I believe this would lead to the ultimate extraction
> given the instant on/instant off thermal stability, and controllable
> [read smooth rampable] flow rate/pressure. It would be a _relatively_
> simple design, and it would offer all the advantages of a piston/lever
> machine, but it would be completely controllable/consistent/ever
> predictable. The only possible disadvantage that I can think of is maybe
> cost [And I suppose that if you really want to make milk beverages, then
> you'll have to look elsewhere to steam/froth... Oh, and I suppose it
> would take a bit longer to make a shot given that water is heated on a
> per shot basis [Although the nice thing is that idle draw ->0W], so make
> that three disadvantages].
>
>
> Calvin wrote:
>> On Feb 19, 5:43 pm, Jonathan Thiessen
>> <jjthies...@student.math.uwaterloo.ca> wrote:
>>> Salutations,
>>>
>>> I was thinking, and I've come up with an idea. Whether it's a
>>> good [or
>>> original] idea, or not, I'm not sure. The plan is to use a portable
>>> induction cooktop with... a pot. The idea is also to have an overhead
>>> electric motor driving a mixing blade, and also to run the cooktop
>>> through a variac which is magically controlled by a fancy temperature
>>> controller like the nice Fuji ones. One of the very nice things about
>>> induction cooktops is that they are rather responsive [much like gas
>>> burners]. In my thinking though, this sort of responsiveness doesn't
>>> mean much if it can't be controlled smoothly [analogue-like, or at least
>>> multi-step]. I've never actually used an induction cooktop before, but
>>> we have a halogen one, and the most annoying aspect of it is that the
>>> different temp settings are realized by it turning off, and on
>>> occasionally which yields a most inconsistent/erratic temp that is
>>> useless for cooking anything but water. I wouldn't want the same sort of
>>> issue with my coffee roasting apparatus. But maybe I'm off on this one
>>> **shrugs**.
>>>
>>> My concerns are:
>>> 1. Running an electric motor close to an induction cooktop. Is this a
>>> problem? [Both being magnetic devices, and all]
>>> 2. Are there temp controllers that are "analogue", or are they all
>>> "digital" in design? That is to say, will they output at a constant
>>> voltage, or off; or can they output smoothly over a range [Lets say
>>> you're ramping up, but going to fast. Instead of letting it go until
>>> it's over temp, it should give a decrease in voltage signaling that the
>>> heater should give a reduced output, and thus avoiding overshooting, and
>>> undershooting]. Should I even be concerned with this? Will it make a
>>> difference? Am I better off to just control a relay with the temp
>>> controller, rather than bothering with smooth temp transition?
>>> 3. Are there variacs that can be controlled via some control voltage. In
>>> other words, can we somehow scale the control voltage output from the
>>> temp controller up to the 0-120VAC sort of range.
>>> 4. Is it ok/safe to run induction cooktops at a reduced voltage? Should
>>> I look for a purely analogue cooktop so that I can set it full-bore, and
>>> let the variac do it's thing? [That is, will running a digitally
>>> controlled unit on a variac screw it up?].
>>> 5. Is this all-round just a really bad idea? I mean... I really quite
>>> like it conceptually so long as it's possible, and [economically]
>>> feasible. What are your thoughts?
>>>
>>> Thank you for your time.
>>> Have a good one ;)
>>> //jonathan
>>
>> I don't know if an inductive cooktop can be run duty cycle and if you
>> will be able to find an SSR that will put up with the abuse. It would
>> definitely be cheaper and easier to use a resistive element like the
>> standalone ones you can get for $15 at any department store. To go
>> the variac route you would need to build a coupling and mount for a
>> servo motor and then build your own temp sensor and PID to drive it;
>> stock PIDs can read a thermocouple and drive an SSR already.
>>
>> It sounds like you are trying to build an automated pan-roaster. I
>> have my doubts that a PID would ever be able to manage such a chaotic
>> and massive system. You would probably need to sample over such a
>> large time frame - tens of seconds - and react so slowly that you
>> would not have the fine control that you are pursuing in the first
>> place. It's a long trip from the range to the bean mass.
>>
>>> From my experience in pan roasting the most important factor is bean
>> movement. You MUST keep the beans in motion in both dimensions. You
>> ability to roast in a controlled way will be a result of finding the
>> right balance between heat transfer from the pot (surface area),
>> charge size (total mass to heat), and stirring (getting that heat into
>> all surfaces of all the beans the same).
>>
>> Good luck and don't let the nay-sayers like me keep you from
>> experimenting.
>>


 
Date: 20 Feb 2007 09:43:29
From:
Subject: Re: Home roasting thoughts
On Feb 19, 3:43 pm, Jonathan Thiessen
<jjthies...@student.math.uwaterloo.ca > wrote:
> Salutations,
>
> I was thinking, and I've come up with an idea. Whether it's a good [or
> original] idea, or not, I'm not sure. The plan is to use a portable
> induction cooktop with... a pot. The idea is also to have an overhead
> electric motor driving a mixing blade, and also to run the cooktop
> through a variac which is magically controlled by a fancy temperature
> controller like the nice Fuji ones. One of the very nice things about
> induction cooktops is that they are rather responsive [much like gas
> burners]. In my thinking though, this sort of responsiveness doesn't
> mean much if it can't be controlled smoothly [analogue-like, or at least
> multi-step]. I've never actually used an induction cooktop before, but
> we have a halogen one, and the most annoying aspect of it is that the
> different temp settings are realized by it turning off, and on
> occasionally which yields a most inconsistent/erratic temp that is
> useless for cooking anything but water. I wouldn't want the same sort of
> issue with my coffee roasting apparatus. But maybe I'm off on this one
> **shrugs**.
>
> My concerns are:
> 1. Running an electric motor close to an induction cooktop. Is this a
> problem? [Both being magnetic devices, and all]
> 2. Are there temp controllers that are "analogue", or are they all
> "digital" in design? That is to say, will they output at a constant
> voltage, or off; or can they output smoothly over a range [Lets say
> you're ramping up, but going to fast. Instead of letting it go until
> it's over temp, it should give a decrease in voltage signaling that the
> heater should give a reduced output, and thus avoiding overshooting, and
> undershooting]. Should I even be concerned with this? Will it make a
> difference? Am I better off to just control a relay with the temp
> controller, rather than bothering with smooth temp transition?
> 3. Are there variacs that can be controlled via some control voltage. In
> other words, can we somehow scale the control voltage output from the
> temp controller up to the 0-120VAC sort of range.
> 4. Is it ok/safe to run induction cooktops at a reduced voltage? Should
> I look for a purely analogue cooktop so that I can set it full-bore, and
> let the variac do it's thing? [That is, will running a digitally
> controlled unit on a variac screw it up?].
> 5. Is this all-round just a really bad idea? I mean... I really quite
> like it conceptually so long as it's possible, and [economically]
> feasible. What are your thoughts?
>
> Thank you for your time.
> Have a good one ;)
> //jonathan

For starters, here are some personal criteria I'd have to satisfy
before embartking on complex invention. Not inclusive or necessarily
the order of importance:
1. I'd have to be an excellent and experienced cupper. Not just I-
know-what-I-like, but having a wide range of controlled and confirmed
experience. Otherwise, how could I trust any of my findings along the
way? How could I sensibly draw from the experiences of a far-flung
community of other experts?
2. I'd have to know what particular aspects of current technology I
want to improve upon. This would require some experience with a
variety of current roasting methods. Simply demonstrating that I
could make a decent roast happen would not not be enough. I'd want to
target a batch size range; not build the unit and then see how much it
could roast. OTOH, if the materials and assembly were handy and cheap,
it's worth trying anything on little more than a hunch.
3. Convenient strorage, aestheticly pleasing, and robustly built
should not be afterthoughts, but considerations from the very
begining. These account for much of the cost of off-the-shelf quality
roasters. So is the goal to build a cheaper Hottop or Probat with the
minor inconveniences of a tangle of exposed wires, corners that singe
and rip flesh, tripped breakers, and which you operate from the floor
of an unheated garage?
tin



  
Date: 20 Feb 2007 19:23:25
From: Ed Needham
Subject: Re: Home roasting thoughts
You work for the government policies and procedures office, right?
(g)

<coffeeemail@gmail.com > wrote in message
news:1171993409.710749.112250@h3g2000cwc.googlegroups.com...
> For starters, here are some personal criteria I'd have to satisfy
> before embartking on complex invention. Not inclusive or necessarily
> the order of importance:
> 1. I'd have to be an excellent and experienced cupper. Not just I-
> know-what-I-like, but having a wide range of controlled and confirmed
> experience. Otherwise, how could I trust any of my findings along the
> way? How could I sensibly draw from the experiences of a far-flung
> community of other experts?
> 2. I'd have to know what particular aspects of current technology I
> want to improve upon. This would require some experience with a
> variety of current roasting methods. Simply demonstrating that I
> could make a decent roast happen would not not be enough. I'd want to
> target a batch size range; not build the unit and then see how much it
> could roast. OTOH, if the materials and assembly were handy and cheap,
> it's worth trying anything on little more than a hunch.
> 3. Convenient strorage, aestheticly pleasing, and robustly built
> should not be afterthoughts, but considerations from the very
> begining. These account for much of the cost of off-the-shelf quality
> roasters. So is the goal to build a cheaper Hottop or Probat with the
> minor inconveniences of a tangle of exposed wires, corners that singe
> and rip flesh, tripped breakers, and which you operate from the floor
> of an unheated garage?
> tin
>