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Main
Date: 26 Jun 2006 19:47:20
From: I->Ian
Subject: HotTop Sweet Spot
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I used Randy "I included your URL, sortof" G's page to install a roast
chamber probe in a HotTop. ;-) :-) ;-)
http://home.surewest.net/frcn/Coffee/HowToHottopTemp.html
NOTE : The Omega probe and HH11A are uncalibrated at roast
temperatures, but agree, at freezer, room and boiling water temps,
within ±0.5°F of the collection of themometers accumulated...
There may be a sweet spot for adding beans to the HotTop, with the
following provisos:
SoCal in summer, indoor temp ~78°F
225±1gram roasts City to City+ [430 to 440 eject temp]
Variac to control element voltage ONLY at ~125+1/-0V until start of
1st crack, then ~102+1/-0V to end of roast
Inserting beans at ~275°F on the Omega results in a better balance of
varietal preservation and body. The temperature is reached at about 1
minute after the HotTop chirps to insert the beans.
Higher insertion temperatures result in a more 'woody, flat' taste and
reduced bean expansion. Lower insertion temperatures produce more
vegetal notes than my wife and I prefer.
Beans used 100% Harrar, 100% Yrgacheffe and blends of 60% Columbia
Supremo or Tanzanian Ruvuma and 20% each Yemen Mocha and Sualwesi
Toraja.
Brewing methods press, Presto Scandi w gold filter and espresso.
So much for the warranty...
YMMV
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Date: 26 Jun 2006 15:41:41
From: Dave S
Subject: Re: HotTop Sweet Spot
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Would you mind telling how you provide control of element voltage only?
Do you mean that you remove the element from the control of the HotTop
electronics?
I am using a Variac to provide 120v to the HotTop plug, but it sounds
like you are doing something different.
How do you control fan on/off?
Dave S.
I- >Ian wrote:
> I used Randy "I included your URL, sortof" G's page to install a roast
> chamber probe in a HotTop. ;-) :-) ;-)
> http://home.surewest.net/frcn/Coffee/HowToHottopTemp.html
>
> SoCal in summer, indoor temp ~78°F
> 225±1gram roasts City to City+ [430 to 440 eject temp]
> Variac to control element voltage ONLY at ~125+1/-0V until start of
> 1st crack, then ~102+1/-0V to end of roast
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Date: 26 Jun 2006 23:47:01
From: I->Ian
Subject: Re: HotTop Sweet Spot
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On Mon, 26 Jun 2006 15:41:41 -0500, Dave S <dabcschell@mts.not > wrote:
>Would you mind telling how you provide control of element voltage only?
>Do you mean that you remove the element from the control of the HotTop
>electronics?
>
>I am using a Variac to provide 120v to the HotTop plug, but it sounds
>like you are doing something different.
>
NOTE : REMOVE ALL ELECTRICAL CONNECTION TO THE HOTTOP.
NOTE : UNLESS YOU ARE TRAINED AND SKILLED AT MODIFICATION OF
ELECTRICAL COMPONENTS WITH LETHAL VOLTAGES AND FAMILIAR WITH ALL
NECESSARY SAFEGUARDS REQUIRED TO PROTECT LIFE AND PROPERTY DO NOT
PROCEED WITH THIS MODIFICATION.
The element is still under control of the HotTop electronics, it just
has more juice while ramping to first crack and less after. Using this
method I'm able to shorten the time to first crack and extend
considerably the time between first crack and second.
The fan does not slow down as it did when dropping the voltage to the
whole machine at first crack, so more heat is removed from the roast,
slowing the ramp. I've yet to stall a roast, but am working toward
that point to determine the end point. Now that I have the temp probe,
I shall see what 'profiles' are attainable, within the limited
confines of element voltage control only.
NOTE : I DISCLAIM ALL RESPONSIBILITY FOR ANY DAMAGE TO YOUR HOTTOP OR
INJURY TO YOU OR ANY OTHER PERSONS INJURED BY FOLLOWING OR FAILURE TO
FOLLOW THESE INSTRUCTIONS. PROCEED ENTIRELY AT YOUR OWN RISK.
If you remove the fan end of the HotTop, you have access to the Main
Circuit board.
http://www.hottopusa.com/fan.html
http://www.hottopusa.com/rear.html
This circuit board is not exactly like the one in my HotTop, but may
provide some help before you begin.
http://www.hottopusa.com/main/main2.jpg
[My PCB had no Heat, Sw1, etc markings]
The A/C Line comes into the board and is marked AC_L. It is the power
cord wire closest to you. That wire links through the thermal fuse T3
& T4 to the rest of the electronics via a white wire that snakes up to
the rear of the roast chamber.
NOTE : BY DOING THIS MODIFICATION, YOU NO LONGER HAVE A THERMAL CUTOUT
TO THE HEATER ELEMENT. IT IS IMPERATIVE THAT THE ROASTER NEVER BE LEFT
UNATTENDED OR OPERATED BY ANYONE WHO DOES NOT FULLY COMPREHEND THE
RISKS OF A FAILURE AND / OR THE PROCEDURE TO FOLLOW IN THE EVENT OF
FAILURE.
NOTE : MONITOR BEAN TEMPERATURE AT ALL TIMES.
If you want to have a thermal cutout to the heater element, either put
the white thermal fuse wire in series with the heater element or add a
second thermal fuse in series with the heater element.
Next to the white wire is a Red wire that is the Live end of the
heating element. It is labeled T5 and is on the edge of the circuit
board closest to you. It is pointed to by the LEFT BLUE arrow in
section 2 of http://www.hottopusa.com/heat.html.
This is the wire to feed from the variac.
The red wire FARTHEST away from you is the low end of the element,
controlled by the HotTop. Do not disconnect this wire.
Materials needed:
1ea. 16ga or larger WHITE 6 foot extension cord
[14ga is larger than 16ga]
1ea. strain relief similar to existing to accomodate the cord
1ea. 1/4" male spade connector. BLUE for 14 to 18ga
1ea. 1/4" female spade connector. BLUE for 14 to 18ga
1ea. 1/4" female to dual male spade 'Y'
1ea. 2"x 1/2" heat shrink tubing
2ea. 4" tie wrap
[I have all this kind of junk lying about, so don't have part
numbers... any auto parts, hardware store should stock... had the
variac over 20 years...]
CAREFULLY Drill a hole in the plastic base of the HotTop near the
original power cord to accomodate the strain relief.
Cut extension cord 4 feet from the PLUG end. I used white and made it
shorter than the standard plug so there is no confusion about which is
which.
Add the FEMALE spade to the Neutral wire on the extension cord. The
Neutral is LARGER of the polarized plug pins. Normally the RIBBED wire
on the cord.
NOTE : TEST YOUR CRIMP BY PULLING FORCEFULLY ON THE WIRE AND THE
CONNECTOR.
Remove the A/C Neutral, AC_N or T2, from the circuit board and install
the spade Y. Connect both neutrals here.
Add the MALE spade to the Line on the extension.
NOTE : TEST YOUR CRIMP BY PULLING FORCEFULLY ON THE WIRE AND THE
CONNECTOR.
Pass through the shrink tubing and plug into the RED wire removed from
T5 above. Slide tubing to cover connectors and secure to cables with
tie wrap.
[T5 is left open on the PCB]
Fasten new cord with strain relief.
Takes less than 30 minutes.
NOTE : MONITOR BEAN TEMPERATURE AT ALL TIMES.
NOTE : MONITOR BEAN TEMPERATURE AT ALL TIMES.
NOTE : MONITOR BEAN TEMPERATURE AT ALL TIMES.
NOTE : MONITOR BEAN TEMPERATURE AT ALL TIMES.
>How do you control fan on/off?
Haven't got there yet. Others have a far more sophisticated control of
the HotTop, which may be in the offing, depending on what else comes
to market between now and when I can justify dumping another three
grand...
http://www.pawlan.com/ccr.html
... which a very fair price, assuming it works as claimed.
>
>Dave S.
>
>I->Ian wrote:
>> I used Randy "I included your URL, sortof" G's page to install a roast
>> chamber probe in a HotTop. ;-) :-) ;-)
>> http://home.surewest.net/frcn/Coffee/HowToHottopTemp.html
>>
>> SoCal in summer, indoor temp ~78°F
>> 225±1gram roasts City to City+ [430 to 440 eject temp]
>> Variac to control element voltage ONLY at ~125+1/-0V until start of
>> 1st crack, then ~102+1/-0V to end of roast
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Date: 27 Jun 2006 07:05:21
From: I->Ian
Subject: Re: HotTop Sweet Spot
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To overcome the thermal fuse problem in the previous post,
add a 120v 15A relay between the heater element hot lead and the
variac line. Power the coil from T5. The relay will close whenever the
HotTop is plugged in.
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Date: 27 Jun 2006 00:37:21
From: DavidMLewis
Subject: Re: HotTop Sweet Spot
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I- >Ian wrote:
> To overcome the thermal fuse problem in the previous post,
> add a 120v 15A relay between the heater element hot lead and the
> variac line. Power the coil from T5. The relay will close whenever the
> HotTop is plugged in.
When I did a similar modification to my Hottop, I sliced the main
circuit board so as to isolate the heater relay contacts and associated
snubber network, then fed those with a separate power cord. That way,
the safety circuitry as well as the main profile control were still in
place, and I could just use the Variac to alter the curve a little.
Seemed to work pretty well. I probably still have pictures someplace.
Best,
David
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Date: 27 Jun 2006 18:05:08
From: BillK
Subject: Re: HotTop Sweet Spot
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> SoCal in summer, indoor temp ~78=B0F
> 225=B11gram roasts City to City+ [430 to 440 eject temp]
> Variac to control element voltage ONLY at ~125+1/-0V until start of
> 1st crack, then ~102+1/-0V to end of roast
What is your typical time to start of first crack?
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Date: 28 Jun 2006 05:52:39
From: I->Ian
Subject: Re: HotTop Sweet Spot
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On 27 Jun 2006 18:05:08 -0700, "BillK" <rcgolfer@gmail.com > wrote:
>
>
>> SoCal in summer, indoor temp ~78°F
>> 225±1gram roasts City to City+ [430 to 440 eject temp]
>> Variac to control element voltage ONLY at ~125+1/-0V until start of
>> 1st crack, then ~102+1/-0V to end of roast
>
>What is your typical time to start of first crack?
Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
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Date: 28 Jun 2006 05:52:10
From: BillK
Subject: Re: HotTop Sweet Spot
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> Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
Hottop told me they have tested the unit to 130V, line input. The
concern in going any further would be the electronics. Given what you
have done, I should think there would be no problem cranking up the
voltage on the element to get down to 10 minutes. Ever tried that?
I'd like to be at about 10 minutes for 225 gm batches.
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Date: 28 Jun 2006 09:18:12
From: Randy G.
Subject: Re: HotTop Sweet Spot
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"BillK" <rcgolfer@gmail.com > wrote:
>> Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
>
>Hottop told me they have tested the unit to 130V, line input. The
>concern in going any further would be the electronics. Given what you
>have done, I should think there would be no problem cranking up the
>voltage on the element to get down to 10 minutes. Ever tried that?
>I'd like to be at about 10 minutes for 225 gm batches.
>
Depending on how far you want to go, it is possible to turn a Hottop
into a programmed or fully manual machine. It gets complicated to
explain but:
- The next step after re-feeding the heating element with a variac but
allowing the electronics to control all processes is to turn the
machine to full manual mode. This can be done by bypassing the control
board completely. I did it once, but you can test what leads on the
ribbon cable control what by unplugging the cable's connector from the
back of the control board and using a jumper wire from the hot lead
(+12v DC - the red wire I think) you can supply voltage to other parts
in order to trigger the operational events- cooling fans, main fan,
ejection door, drum rotation and heating element. As far as the main
fan, it can actually run at full speed through the entire roast which
will evacuate more smoke for a cleaner taste (so I have been told).
The ambitious person could then reconnect the board so that the temp
display still works, but bypass all other functions work manually with
a set of small mechanical switches on a board. Otherwise just make
your own control panel like in a 1950's sci fi movie with Dymo labels
above and below the switches ("Plan 9 From Outer Space").
-The next step would be to add an RS232 programmable PID to control
the heating element and enable programming. This would involve having
two temp sensors one in the roasting chamber to retrieve air temp and
another in the beans to compare- you don't want to control the PID
from bean temp alone because the beans would be tipped or burnt
because of the lag in bean temp.
The ultimate is the control that Jeffery Pawlan has accomplished with
his CCR, which has a level of control that would actually be able to
recreate just about any roast you would like, making it an excellent
sample roaster for commercial purposes.
Randy "hard to tipe tuday" G.
http://www.EspressoMyEspresso.com
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Date: 28 Jun 2006 23:34:42
From: Bob Yellin
Subject: Re: HotTop Sweet Spot
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>> Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
>
>Hottop told me they have tested the unit to 130V, line input. The
>concern in going any further would be the electronics. Given what you
>have done, I should think there would be no problem cranking up the
>voltage on the element to get down to 10 minutes. Ever tried that?
>I'd like to be at about 10 minutes for 225 gm batches.
I've had cranked it up as far as 132V and regularly hit 130V with no ill
effects after more than three years of running it this way on a regular
basis. But that's me; YMMV...
My shortest roast time so far was about 11 1/2 minutes with 1st crack at 9
minutes with a 150-gram load. First crack will often come at 400F dead nuts
on my Omega TC probe that I've been using for about 2 years.
Bob
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Date: 28 Jun 2006 22:54:13
From: Dave S
Subject: Re: HotTop Sweet Spot
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Bob Yellin wrote:
>>> Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
>> Hottop told me they have tested the unit to 130V, line input. The
>> concern in going any further would be the electronics. Given what you
>> have done, I should think there would be no problem cranking up the
>> voltage on the element to get down to 10 minutes. Ever tried that?
>> I'd like to be at about 10 minutes for 225 gm batches.
>
> I've had cranked it up as far as 132V and regularly hit 130V with no ill
> effects after more than three years of running it this way on a regular
> basis. But that's me; YMMV...
>
> My shortest roast time so far was about 11 1/2 minutes with 1st crack at 9
> minutes with a 150-gram load. First crack will often come at 400F dead nuts
> on my Omega TC probe that I've been using for about 2 years.
>
> Bob
Is that "cranked it up as far as 132V" at the plug, or have you isolated
the heater, and sent 132V to only the heater?
I wouldn't mind shortening, and intensifying the roast, but if I have to
cut the load down to 150 grams, I might as well stay with my Poppery.
Dave S.
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Date: 29 Jun 2006 07:24:15
From: Bob Yellin
Subject: Re: HotTop Sweet Spot
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>Bob Yellin wrote:
>>>> Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
>>> Hottop told me they have tested the unit to 130V, line input. The
>>> concern in going any further would be the electronics. Given what you
>>> have done, I should think there would be no problem cranking up the
>>> voltage on the element to get down to 10 minutes. Ever tried that?
>>> I'd like to be at about 10 minutes for 225 gm batches.
>>
>> I've had cranked it up as far as 132V and regularly hit 130V with no ill
>> effects after more than three years of running it this way on a regular
>> basis. But that's me; YMMV...
>>
>> My shortest roast time so far was about 11 1/2 minutes with 1st crack at 9
>> minutes with a 150-gram load. First crack will often come at 400F dead nuts
>> on my Omega TC probe that I've been using for about 2 years.
>>
>> Bob
>
>Is that "cranked it up as far as 132V" at the plug, or have you isolated
>the heater, and sent 132V to only the heater?
>
>I wouldn't mind shortening, and intensifying the roast, but if I have to
>cut the load down to 150 grams, I might as well stay with my Poppery.
>
>Dave S.
That's the voltage to the plug measured with a permanently-mounted
panel-style digital voltmeter. You might be able to get close to those
times with a larger load by playing with the preheat time - the time after
the "ready" beeps have ended and the time that you input the beans. If
memory serves, I was waiting until about 400F before pouring in the beans.
Bob
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Date: 29 Jun 2006 17:09:50
From: I->Ian
Subject: Re: HotTop Sweet Spot
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On Thu, 29 Jun 2006 07:24:15 -0400, Bob Yellin <bobyellin@gmail.com >
<snip >
>That's the voltage to the plug measured with a permanently-mounted
>panel-style digital voltmeter. You might be able to get close to those
>times with a larger load by playing with the preheat time - the time after
>the "ready" beeps have ended and the time that you input the beans. If
>memory serves, I was waiting until about 400F before pouring in the beans.
>
>Bob
Don't you find that adversely affects the taste? When I tried that,
the taste was closer to my old FR and HWP.
my 2p : The primary flaws with the HotTop : too long to ramp up the
temperature after insertion and too short a ramp from first to second
crack.
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Date: 28 Jun 2006 18:57:17
From: I->Ian
Subject: Re: HotTop Sweet Spot
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On 28 Jun 2006 05:52:10 -0700, "BillK" <rcgolfer@gmail.com > wrote:
>> Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
>
>Hottop told me they have tested the unit to 130V, line input. The
>concern in going any further would be the electronics. Given what you
>have done, I should think there would be no problem cranking up the
>voltage on the element to get down to 10 minutes. Ever tried that?
>I'd like to be at about 10 minutes for 225 gm batches.
Not yet, but if you send me $10,000 so I can get my $50 million out of
Rwanda, I'll try it tonight.
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Date: 29 Jun 2006 05:46:23
From: I->Ian
Subject: Re: HotTop Sweet Spot
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On Wed, 28 Jun 2006 18:57:17 GMT, "I- >Ian" <someone@nowhere.com>
wrote:
>On 28 Jun 2006 05:52:10 -0700, "BillK" <rcgolfer@gmail.com> wrote:
>
>>> Around 12 to 13 minutes. Without the variac, ~15:30 to 16:30+
>>
>>Hottop told me they have tested the unit to 130V, line input. The
>>concern in going any further would be the electronics. Given what you
>>have done, I should think there would be no problem cranking up the
>>voltage on the element to get down to 10 minutes. Ever tried that?
>>I'd like to be at about 10 minutes for 225 gm batches.
>
>Not yet, but if you send me $10,000 so I can get my $50 million out of
>Rwanda, I'll try it tonight.
All I can get out of the variac to the element is 128.5v.
Time to first crack for 225g 60% Tanz 20% each Yemen Mocca and
Sulawesi changed from 13:15 to 12:30.
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