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Date: 11 Jan 2007 23:40:40
From:
Subject: How to disassemble i-roast2 ? need help
I am not satisfied with this machine's performance. The temperature
read on the LCD can not be trust really. Sometimes it is about 50 C
lower than the actual temp (read by thermometer). So I can't get the
desired temperature at every stage. The machine will try to touch the
preset-temp with full power from beginning to the end.I could roast the
bean into dark, but I can not get the curve I want. This is my third
machine. The previous are returned. I want to make some improvement,
but I don't know how to disassemble it. Any advice would be
appreciated.





 
Date: 22 Jan 2007 12:19:41
From: JulesG
Subject: Re: How to disassemble i-roast2 ? need help
Humm... I have the same regular temperature profiles with my programs
without any modifications other than using a thermocouple. I don't see
any benefits in modifying the iR2.



 
Date: 21 Jan 2007 20:14:31
From: alt.coffee
Subject: Re: How to disassemble i-roast2 ? need help
I have uploaded some pics to Google Picasa Album.
http://picasaweb.google.com/jiaju.wu/IROAST2MOD

The chart show the temperature controlled by I-roast2 before modified.
The purple curve is from thermometer,the blue curve is what I
programmed and the yellow curve is from the machine. I placed the probe
at the inner corner of the chaff filter.Maybe it would be better ,where
is the bean mass. The shortcoming of the Iroast2 I think is I can not
control the temperature once I push the button. Sometimes it is really
climb too fast especialy at the dewater stage.

The other pics are the machine after modified. I add a copper bracket
to support the probe. And due to small room in the machine I connect
all the addons from outside of the machine which were placed into a
small box.


The total cost list below:(IN CHINA)
PID:20USD
SSR(10A):5USD
RELAY(10A):1USD
Heat-Resist Cord ,Conections,Box and others:7USD

Yes,I would not plan to improve it with advanced devices.

"JulesG =D0=B4=B5=C0=A3=BA
"
> Thanks for the info on the internals of the iR2.
>
> I was interested in tweaking it somewhat from the inside to improve
> temperature control. However reading your post, because of design and
> lack of space, I don't think it is really feasible. Also, I don't
> think it is strurdy enough to reliably support extensive modifications.
> Money would probably be better spent on a drum type more sophisticated
> unit.
>
> Also, as is, it performs quite well for a fluid bed roaster. With
> experimentation, one is capable to program very smooth roasting curves
> that can be repeated time after time, and that can last up to the full
> 15 minutes of available programming time.
>
> I see only 2 easily added improvements to the iR2:
> 1- Use of a thermocouple to measure the temperature of the bean mass.
> No real modification needed except slightly enlarging a hole in the top
> cover and one in the chaff filter basket.
> 2- Use of a variac to ensure a stable A/C voltage, the only variable
> that one doesn't control.
>
> The first mod is easy to do and cheap - I have done it and it makes
> experimentation easier and more effective. The variac is expensive
> however, I don't think it is worth it.



 
Date: 21 Jan 2007 05:06:00
From: JulesG
Subject: Re: How to disassemble i-roast2 ? need help
Thanks for the info on the internals of the iR2.

I was interested in tweaking it somewhat from the inside to improve
temperature control. However reading your post, because of design and
lack of space, I don't think it is really feasible. Also, I don't
think it is strurdy enough to reliably support extensive modifications.
Money would probably be better spent on a drum type more sophisticated
unit.

Also, as is, it performs quite well for a fluid bed roaster. With
experimentation, one is capable to program very smooth roasting curves
that can be repeated time after time, and that can last up to the full
15 minutes of available programming time.

I see only 2 easily added improvements to the iR2:
1- Use of a thermocouple to measure the temperature of the bean mass.
No real modification needed except slightly enlarging a hole in the top
cover and one in the chaff filter basket.
2- Use of a variac to ensure a stable A/C voltage, the only variable
that one doesn't control.

The first mod is easy to do and cheap - I have done it and it makes
experimentation easier and more effective. The variac is expensive
however, I don't think it is worth it.



 
Date: 20 Jan 2007 12:16:15
From: alt.coffee
Subject: Re: How to disassemble i-roast2 ? need help
When you disassemble it you would find it could be divided into some
parts. motor and heating control,LCD control panel,fan and heating
assemble,LC filter,variable voltage(triac) control . Modify the heating
element circuit and place the SSR into it (due to samll space I conect
it from outside). Bypass the triac(isolate it) with a relay,which would
increase the temperture control ability. Furthermore I conect a
potentiometer to the LCD control panel instead of the heat sensor,which
I could control the fan speed.What the negative are lost memoriable
curve,roughly fan speed control and no outlet tempterture display.Sound
like bad but I got fan speed control and precise temperture. What do
you think?
More improvement:
a pid with rs485 comunication interface controlled by a computer(create
your favorite curve).
Two phase motor controlled by variable voltage from Triac(I think it is
enough,variable frequence control may be better ,but it is too complex
)=2E
"JulesG =D0=B4=B5=C0=A3=BA
"
> alt.coffee wrote:
> > Thanks for your reply.
> > I do the test again according to the program 8. I noted the report
> > temp(from i roast2) and record temp(from themometer) every 20 seconds.
> > Finally I got a curve and compared it with what described in the
> > review. I found the temp climb too fast.
> > As a result there are some dents on the surface and looked like a bit
> > burned.
> > I really think the i roast2 is weak of control the temp.
> > Lately I disassemble the machine with a special tool. I study the
> > circuit and add a pid device into it.This not a short story. I got the
> > precised temp control. I would not have nothing to do when roasting.I
> > could monitor the temp and tune it to the degree I prefered. I got much
> > more from roasting.
> >=20
> >=20
> > "race8680 =D0=B4=B5=C0=A3=BA
>=20
>=20
> How did you do that ?



 
Date: 17 Jan 2007 15:00:47
From: JulesG
Subject: Re: How to disassemble i-roast2 ? need help

alt.coffee wrote:
> Thanks for your reply.
> I do the test again according to the program 8. I noted the report
> temp(from i roast2) and record temp(from themometer) every 20 seconds.
> Finally I got a curve and compared it with what described in the
> review. I found the temp climb too fast.
> As a result there are some dents on the surface and looked like a bit
> burned.
> I really think the i roast2 is weak of control the temp.
> Lately I disassemble the machine with a special tool. I study the
> circuit and add a pid device into it.This not a short story. I got the
> precised temp control. I would not have nothing to do when roasting.I
> could monitor the temp and tune it to the degree I prefered. I got much
> more from roasting.
>=20
>=20
> "race8680 =D0=B4=B5=C0=A3=BA


How did you do that ?



 
Date: 17 Jan 2007 11:43:20
From: alt.coffee
Subject: Re: How to disassemble i-roast2 ? need help
Thanks for your reply.
I do the test again according to the program 8. I noted the report
temp(from i roast2) and record temp(from themometer) every 20 seconds.
Finally I got a curve and compared it with what described in the
review. I found the temp climb too fast.
As a result there are some dents on the surface and looked like a bit
burned.
I really think the i roast2 is weak of control the temp.
Lately I disassemble the machine with a special tool. I study the
circuit and add a pid device into it.This not a short story. I got the
precised temp control. I would not have nothing to do when roasting.I
could monitor the temp and tune it to the degree I prefered. I got much
more from roasting.


"race8680 =D0=B4=B5=C0=A3=BA
"
> jiaju...@gmail.com wrote:
> > I am not satisfied with this machine's performance. The temperature
> > read on the LCD can not be trust really. Sometimes it is about 50 C
> > lower than the actual temp (read by thermometer). So I can't get the
>
> The reading on the LCD is the air inlet temperature, which the iRoast
> seems to control or attempt to control depending on bean mass. The
> thermodynamics of the roaster clearly result in some static pressure
> recovery and temperature rise, since the beans get substantially hotter
> than the programmed temperature in later stages of roast.
>
> > desired temperature at every stage. The machine will try to touch the
> > preset-temp with full power from beginning to the end.I could roast the
> > bean into dark, but I can not get the curve I want. This is my third
>
> What curve do you want? A few roasts with a TC placed in the bean mass
> should give you enough to go on to manipulate the programmed roast
> numbers to generate the curve you're seeking. I've created several
> profiles this way based on limited trial and error, converging on the
> result I'm looking for. Otherwise, consider throwing down the extra
> cash for a genecafe or other with more easily controlled time/temps.
>
>
>
> > machine. The previous are returned. I want to make some improvement,
> > but I don't know how to disassemble it. Any advice would be
> > appreciated.
>=20
> Good luck,
> -n



 
Date: 12 Jan 2007 10:25:30
From: race8680
Subject: Re: How to disassemble i-roast2 ? need help

jiaju...@gmail.com wrote:
> I am not satisfied with this machine's performance. The temperature
> read on the LCD can not be trust really. Sometimes it is about 50 C
> lower than the actual temp (read by thermometer). So I can't get the

The reading on the LCD is the air inlet temperature, which the iRoast
seems to control or attempt to control depending on bean mass. The
thermodynamics of the roaster clearly result in some static pressure
recovery and temperature rise, since the beans get substantially hotter
than the programmed temperature in later stages of roast.

> desired temperature at every stage. The machine will try to touch the
> preset-temp with full power from beginning to the end.I could roast the
> bean into dark, but I can not get the curve I want. This is my third

What curve do you want? A few roasts with a TC placed in the bean mass
should give you enough to go on to manipulate the programmed roast
numbers to generate the curve you're seeking. I've created several
profiles this way based on limited trial and error, converging on the
result I'm looking for. Otherwise, consider throwing down the extra
cash for a genecafe or other with more easily controlled time/temps.

http://www.quiknet.com/frcn/Coffee/iRoast2.html

> machine. The previous are returned. I want to make some improvement,
> but I don't know how to disassemble it. Any advice would be
> appreciated.

Good luck,
-n