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Topic: Alpenrost stuck on hot (5 msgs / 175 lines)
1) From: liptak
Sorry if this topic has been discussed a zillion times, I went over a lot of 
threads regarding to Alp in the mailing list archive (and searching in Google 
database), but haven't found the answer for my problem.
I recently bought an used Alpenrost v.1.1 (white sticker on the bottom CBR 
(E) - 1023) here in Slovakia (Eastern Europe). The first 'demo' roast with 
the previous owner went OK (24C ambient, indoors, 200gr of Ecuador Amazonas, 
position 07 - resulted in a dark roast after full 22 minute or so cycle).
Then after some days I decided to clean the unit, as it was dirty enough (no 
shining inside, lot of stinky film). I decided to pull up the heating spiral 
and clean the metal cover under the spiral. When I unscrewed the brackets, I 
realised that there is a thin metal wire attached to the middle of the 
spiral, probably a heat sensor. I was unable to pull up the spiral because of 
this, so sadly I hade to screw the brackets back. I did the cleaning, the 
whole unit now shines as new (I used oven cleaner from Astonish).
My first roast after the cleaning was a bit surprise, as there was 
practically no gap between the first and the second crack, and the first 
crack came as 6 or 7 minutes after turning the machine on (I learned from the 
posts that it is always better to roast 'by ears'). The roast was very 
uneven, beans came out with all the variety roast you can imagine from 
cinnamon to a piece of coal.
I did another study over the net and found that probably my machine is stuck 
on heating. I then tried two or three runs without the drum, with lid open, 
holding stopwatch. After 1 minute the spiral is going to shine, develops to 
full shining in 2:00 and stays on like that till the end (16:30 on 01). There 
is no power cycling to the spiral, as mentioned in many newsgroups (heat 
control).
After another study I found the existency of the potentiometer on the PCB of 
the Alp, and tried to tweak it with no luck. It seems that the pot controls 
the heat only when the heat control is in duty, which in my case is probably 
not.
I thought I made something wrong with the thin metal wire connected to the 
heating spiral, so I unscrewed the omega bracket which covers the spiral and 
found that the wire is still on place, and there is no visible error with 
that.
Right now I'm stuck with my problem in this point. If there is anybody who 
went over the same problem, I would realy appreciate some hints how to get my 
Alp back to healthy operation.
Thank you,
Kristian

2) From: Rick Farris
Kristian,
I don't want to sound like a smart aleck (this time) but you mentioned
running the Alp with the lid open holding a stopwatch and watching the
heating coils.
If the lid is open, the heating coils will never go off because the Alp
is thermostatically controlled.
I no longer have an Alp and I can't remember if the Alp made a noise
(like a change in speed of the fan, maybe) when the heating coils came
on, but you might try listening for that.  Also, a variac with a current
meter built in, or even a voltmeter across the ac line might detect
fluctuations associated with the coils coming on.
Best, however, might be to get a long-necked thermometer (like those
intended to be used with a gas or charcoal fired grill) and file a notch
in the bean cup so that the thermometer can be inserted from the end
into the middle of the roasting chamber.  As I remember, the Alp
controls on 550 F.  If your temperature is constant at about 550 =
F,
it's working correctly.
-- Rick

3) From: liptak
Rick,
this explanation sounds reasonable. I didn't think that the Alp is smart 
enough to burn full power with the lid open.
From what I've read on the net and this awesome mail list, I have to drill a 
hole in the lid to be able to put an thermometer in. I do not want to go so 
far at this point, I'm patient enough to roast by ears and switch the machine 
off in the right time.
I'm going to do some tests with actual load. By the way I called Bruno at 
Swissmar and he told me he will pass my problem to the engineer, and if he 
will be able to find what could cause my problem, they could send me a spare 
part to repair my Alp.
Regards,
Kristian
Quoting Rick Farris :
<Snip>
--

4) From: Rick Farris
Kristian writes:
<Snip>
It's not smart -- it just has a thermostat -- it's like running your
furnace with the doors open in the winter.
<Snip>
Not true.  All you have to do is get a triangular or round file about
1/4" in diameter and file a notch in the bean cup, right in the middle
of the lip.  That way the thermometer lays across the bean cup with it's
end inside the roasting chamber.  You can do it without the notch, but
that means that the lid can't close all the way, so it's better to notch
it.
-- Rick

5) From: liptak
Rick,
<Snip>
I tought the thermostat is beneath the heating spiral, thus not affected by 
the opened lid.
I did a test roast with actual load in it, and it seems that with the closed 
lid the situation is the same, I've reached the first crack after 5 minutes, 
second crack 30 seconds after, I pressed the cool button at 6:30. Result - 
uneven roast, practically no chaff. I did a sneak peek at 3:00, opened the 
lid for 2-3 cm (1 inch) and saw orange heating spiral :-(
Thermosensor is definitely bad, and I will have to wait for Swissmar's answer 
on that. I'm wondering if I can break my spiral when running it on full power 
for the roasting time until the fix.
And of course, I'm going to play Cinderella, select the cinnamon like beans 
from the roast to have them roasted again.
Regards,
Kristian


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