[Homeroast] Drum rotation > Jimma > PID iRoast

michael kaericher mike_kae at yahoo.com
Mon Oct 11 09:37:58 CDT 2010


It's also not all that hard to crack the door open periodically after 1C starts.  I tend to do about 3 seconds of every 15.

Overall I do agree about more control at the end though.  Most important for me would be some way to bypass the end time.  Like a "don't end now button".  To prevent a user from  letting the roast run way to long, the button could be one that has to be held in as long as the user wants the roast to continue, or it could extend the roast for small periods (30 seconds) and need to be pressed in the last 10 seconds of the roast.

I sent similar feedback to to Behmor already.  Joe Behm contacted me and noted that this is a feature that he is trying to figure out how to work in.  He would like to work it in in such a way that existing users can take advantage of it. (Though I noted that I am not averse to buying and installing a replacement control panel if it would offer additional control)

I'll send another reply to this with my email chain with Joe Behm.


-Mike





--- On Sat, 10/9/10, ricky carter <rickylc99 at gmail.com> wrote:

From: ricky carter <rickylc99 at gmail.com>
Subject: Re: [Homeroast] Drum rotation > Jimma > PID iRoast
To: "A list to discuss home coffee roasting. There are rules for this list, available at http://www.sweetmarias.com/maillistinfo.html" <homeroast at lists.sweetmariascoffee.com>
Date: Saturday, October 9, 2010, 11:30 AM

I completely agree with the comment about all profiles ending in 100% power,
it's the biggest hurdle for me with the behmor, P2 is an alternative, but
getting the cutback timed just right is a challenge.  a user initiated low
medium and high heat setting would make the Behmor a very nice roaster.

Of course it can be done by modding the roaster, but it would be nice if it
was built in.

On Sat, Oct 9, 2010 at 11:33 AM, Edward Bourgeois <edbourgeois at gmail.com>wrote:

> One thing that has baffled me is why all the profiles end with a 100%
> power. This goes against what the beans need after 1st crack and adds
> to the chaff singeing issue.
>
> On Sat, Oct 9, 2010 at 11:19 AM, Edward Bourgeois <edbourgeois at gmail.com>
> wrote:
> > Pro roaster design has been tweaked for many years. Much effort, r&d,
> > $$$ has gone into fin/vane design and adjusting to the proper speed
> > for the design. I'm very happy with my hybrid homebuilt but got a
> > Behmor (thank you John) early after it's release to play around with.
> > There's much to like about it. But as most 1st models it has some
> > design issues that can be improved upon. Drum speed it certainly one.
> > Agitation is very important for quality of roast along with
> > efficiency. Increasing drum speed has allowed for improvements in both
> > these areas(I'm running 50rpm but also have a 30rpm I could try and
> > compare). I still haven't had a chance to really test the chaff issue
> > Tom mentioned but in the few roasts I've done it didn't start a chaff
> > issue that was bad enough for me to notice. I've thought about trying
> > to lower the floor a bit  and redesign the chaff tray but just haven't
> > gotten around to it. For anyone who didn't see my recent mod. post you
> > can check out my blog below.
> >
> > On Thu, Sep 30, 2010 at 12:20 PM, miKe mcKoffee <mcKona at comcast.net>
> wrote:
> >> First I'll say I'm not a roaster designer or manufacturer so can't say
> >> exactly how specific drum rotation speeds are chosen for different
> roasters.
> >> Before his passing Ron did a fair amount of testing for various drums
> and
> >> drum diameters to determine how fast was too fast for his Q drums. IE at
> >> what speed would the beans not loft but instead have centrifugal force
> push
> >> them against the wall. IRC the HotTop drum rotation is ~30rpm (checked
> it
> >> but that was almost 3 years ago so memory fades), USRC 3k ~65rpm, Behmor
> >> very slow ~6rpm. Observation of other commercial drum roasters and their
> >> observed bean loft means using similar speeds to measured (counted) USRC
> >> drum speed.
> >>
> >> A common mistake is thinking the drum itself is the primary heat source
> for
> >> drum roasted beans. Modern drum roasters convection accounts for about
> 80%
> >> of the roast energy, air roasters even more. While the specific pre-heat
> of
> >> the drum and roaster IS VERY important at the beginning of the roast,
> it's
> >> importance is it's stored energy which is applied primarily via
> convection
> >> and radiation not conduction. With a bit of understanding of the types
> of
> >> heat in the roast process and observation of various roasters it becomes
> >> clear constant loft of the beans by the drum is the goal. Convection is
> the
> >> primary heat transfer in all modern roasters.  (See a good article by
> Terry
> >> Davis, originally written for Roast Magazine IIRC
> >> http://www.ambexroasters.com/information/read/heat_transfer.html )
> >>
> >> If the beans aren't vigorously tumbling convection can't occur for the
> >> majority of the beans stuck in a barely moving mass. This leaves
> conduction
> >> and radiation as the more predominant roast energies, which is the
> problem
> >> with the stock Behmor. Radiant energy primarily from the heater and
> >> pre-heated roast chamber primarily affecting the beans on the outside of
> the
> >> mass and conduction later in the roast bean to bean. At the same time I
> >> split out the heater for variac control Alchemist John put in a faster
> drum
> >> motor, with marked improved results. (We both had/have first production
> run
> >> Behmors from Joe) I never got a roast I was satisfied with just by
> directly
> >> controlling radiant heat, ie the heater. Some "ok" roasts to be sure,
> but
> >> nothing as good as Caffe Rosto profiled roasts or later CCR HotTop
> roasts.
> >> Convection or lack thereof was the apparent difference.
> >>
> >> IF a faster drum rotation causes problems with the Behmor Alchemist can
> >> chime in since fairly certain he's been using IIRC ~45rpm drum motors
> for
> >> close to 3 years.
> >>
> >> It's easy to turn beans brown, it's a lifetime Journey learning how to
> make
> >> beans sing. IMO (and that of many others) a huge part of the process is
> >> learning how to effectively control your particular roaster.
> >>
> >> Slave to the Bean  miKe mcKoffee
> >> www.CompassCoffeeRoasting.com <http://www.compasscoffeeroasting.com/>
> >> URL to Rosto mods, FrankenFormer, some recipes etc:
> >> http://www.mckoffee.com/
> >>
> >> Ultimately the quest for Koffee Nirvana is a solitary path. To know I
> must
> >> first not know. And in knowing know I know not. Each Personal
> enlightenment
> >> found exploring the many divergent foot steps of Those who have gone
> before.
> >>
> >> Sweet Maria's List - Searchable Archives
> >> http://themeyers.org/HomeRoast/
> >>
> >>
> >>> -----Original Message-----
> >>> From: homeroast-bounces at lists.sweetmariascoffee.com
> >>> [mailto:homeroast-bounces at lists.sweetmariascoffee.com] On
> >>> Behalf Of Jim Couch
> >>> Sent: Thursday, September 30, 2010 7:49 AM
> >>>
> >>> Believe I saw some comments from Tom cautioning about the "dangers" of
> >>> spinning a Behmor drum too fast, something about it causing
> >>> chaff collection
> >>> problems and messing with the ability of the beans to
> >>> transfer heat to each
> >>> other perhaps problems would be a better word than dangers..........
> >>>
> >>> On Thu, Sep 30, 2010 at 8:36 AM, Robert Yoder
> >>> <robotyonder at hotmail.com>wrote:
> >>>
> >>> >
> >>> > Hi MiKe,
> >>> >
> >>> >
> >>> > Thanks for your posts!  So much to learn!
> >>> >
> >>> > >
> >>> >   Even directly controlling the heater via variac
> >>> > > didn't help enough because drum rotation was so slow yielding poor
> >>> > > convection. If I hadn't acquired a CCR HotTop so soon
> >>> after the Behmor
> >>> > > likely would have mod'd it further with faster drum and bean temp
> >>> > probemaking it a decent roaster.
> >>> >
> >>> >
> >>> >
> >>> > Can you clarify the drum-rotation/poor convection comment?
> >>> Is there a
> >>> > typical shop-roaster drum-rotation speed?  How is that chosen?
> >>> >
> >>> > Happy Roasting,
> >>> >
> >>> > robert yoder
> >>
> >>
> >> _______________________________________________
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> >>
> >
> >
> >
> > --
> > Ed Bourgeois aka farmroast
> > Amherst MA.
> > http://coffee-roasting.blogspot.com/
> >
>
>
>
> --
> Ed Bourgeois aka farmroast
> Amherst MA.
> http://coffee-roasting.blogspot.com/
>
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