HomeRoast Digest


Topic: adventures in *destruction derby* roasting (3 msgs / 151 lines)
1) From: Mike McGinness
Got an email early evening from a co-worker who's also a homeroaster with an
emergency situation. His FR chamber is falling apart and his newer Rosto is
a piece of crap only roasting to very very light. He was wondering if I
could roast some for him and check out his Rosto.
Of course I said no problem come on over. Fired up my FrankenFormer Rosto
(FFR) and got some of his CR Miel greens a roastin' (from SM of course, we
split 20# of it when it first came in). So far so good. Plugged his Rosto
into another circuit with my second thermometer and drilled lid to see how
hot it would go empty. Maxed out 310 8min later. Compared it with the 20
cooler of my two Rostos, it maxed out at 390. His definitely a lemon. Did a
couple more FFR batches for him then we decided to see if we could variac
push his to a decent roast. I speculated since it's one of the newer Rostos
chances are the thermal fuse would fry. We laughed and figured worst case
scenario would be a strange profile indeed of a partial roast getting dumped
into one of my Rostos to completion. Plugged his Rosto (stock single voltage
in) into my FrankenFormer (heavy variac heater side.) Started it at 120v
with 151gr greens, my usual. Since fan voltage *so low* used my old Rockin'
Rosto technique early on. Temp climbed to around 360 and stalled so I
started pushing the voltage. Had the voltage up to about 130v as temp
approached 400 and wouldn't you know it, thermal fuse blows as I predicted!
By the time got the beans transferred to one of my Rostos and roast
re-started bean temp was down close to 200. Brought it up to light full
city 440 about 15:30min total time including time in his Rosto and transfer
to mine.
Wait, it gets better! Decided to do a FR speed roast emulation for him since
that's what he's used to. Started another batch heater all out 130v. Less
than a minute into the roast smoke started coming from inside Frankie!
Quickly shut down. What the heck was going on. I've pushed Frankie this hard
many times. Visual inspection and touching for hot components yielded nada.
Checked no load fan & heater voltages okie-dokie. Ok, what's going on.
Plugged in my other Rosto, empty, and fired her up while we watched
Frankie's internals. Flipped the heater switch on-off-on a couple times
(which I sometimes do during a roast to quickly compensate for too fast ramp
while lowering voltage). Suddenly smoke again from the heater variac side
and voltage to heater died. Variac was cold to the touch, not even being
pushed at all. Neither of us could pin point the failure. I figured it was
the switch internal contacts fried even though over spec'd. Restarted the
roast running fixed direct plug heater and fan side variac. It was now a
little after 8pm, hadn't had dinner, so we called it a session.
Just re-inspected FrankenFormer and found the culprit not to be the switch
but one of the twist connector groupings coming from the switch. Seems one
of my groupings was not good and overheated melting the connector.
Re-stripped the wires and put on new connector. Tested out all go! Life is
good.
MM;-)
FrankenFormer Rosto Roastin' - Royally Balance Brewin'
Rocky grindin' - Miss Silvia brewin' too!
PNW HomeRoast List Gathering Info' URLhttp://home.attbi.com/~mdmint/coffee/pnwhrg.htm

2) From: miKe mcKoffee
Got an email early evening from a co-worker who's also a homeroaster with an
emergency situation. His FR chamber is falling apart and his newer Rosto is
a piece of crap only roasting to very very light. He was wondering if I
could roast some for him and check out his Rosto.
Of course I said no problem come on over. Fired up my FrankenFormer Rosto
(FFR) and got some of his CR Miel greens a roastin' (from SM of course, we
split 20# of it when it first came in). So far so good. Plugged his Rosto
into another circuit with my second thermometer and drilled lid to see how
hot it would go empty. Maxed out 310 8min later. Compared it with the 20
cooler of my two Rostos, it maxed out at 390. His definitely a lemon. Did a
couple more FFR batches for him then we decided to see if we could variac
push his to a decent roast. I speculated since it's one of the newer Rostos
chances are the thermal fuse would fry. We laughed and figured worst case
scenario would be a strange profile indeed of a partial roast getting dumped
into one of my Rostos to completion. Plugged his Rosto (stock single voltage
in) into my FrankenFormer (heavy variac heater side.) Started it at 120v
with 151gr greens, my usual. Since fan voltage *so low* used my old Rockin'
Rosto technique early on. Temp climbed to around 360 and stalled so I
started pushing the voltage. Had the voltage up to about 130v as temp
approached 400 and wouldn't you know it, thermal fuse blows as I predicted!
By the time got the beans transferred to one of my Rostos and roast
re-started bean temp was down close to 200. Brought it up to light full
city 440 about 15:30min total time including time in his Rosto and transfer
to mine.
Wait, it gets better! Decided to do a FR speed roast emulation for him since
that's what he's used to. Started another batch heater all out 130v. Less
than a minute into the roast smoke started coming from inside Frankie!
Quickly shut down. What the heck was going on. I've pushed Frankie this hard
many times. Visual inspection and touching for hot components yielded nada.
Checked no load fan & heater voltages okie-dokie. Ok, what's going on.
Plugged in my other Rosto, empty, and fired her up while we watched
Frankie's internals. Flipped the heater switch on-off-on a couple times
(which I sometimes do during a roast to quickly compensate for too fast ramp
while lowering voltage). Suddenly smoke again from the heater variac side
and voltage to heater died. Variac was cold to the touch, not even being
pushed at all. Neither of us could pin point the failure. I figured it was
the switch internal contacts fried even though over spec'd. Restarted the
roast running fixed direct plug heater and fan side variac. It was now a
little after 8pm, hadn't had dinner, so we called it a session.
Just re-inspected FrankenFormer and found the culprit not to be the switch
but one of the twist connector groupings coming from the switch. Seems one
of my groupings was not good and overheated melting the connector.
Re-stripped the wires and put on new connector. Tested out all go! Life is
good.
MM;-)
FrankenFormer Rosto Roastin' - Royally Balance Brewin'
Rocky grindin' - Miss Silvia brewin' too!
PNW HomeRoast List Gathering Info' URLhttp://home.attbi.com/~mdmint/coffee/pnwhrg.htm

3) From: Ed Needham
Sounds like an easy fix.  'Whew' is right.  It's nerve wracking when our
'dear to our heart' projects go belly up.  Glad your was just a glitch.
Ed Needham
To Absurdity and Beyond!http://www.homeroaster.comed
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HomeRoast Digest