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Second crack

Posted: Tue 24 Mar, 2020 2:22 pm
by Sam
Hi All,

Can anyone hear second crack above the fan noise? I can't, am I missing something?

In the absence of an audible second crack, what are people doing to "log" second crack? What should I be looking or listening for?

Thanks,

Sam

Re: Second crack

Posted: Tue 24 Mar, 2020 2:35 pm
by kaffelogic
In my experience different beans vary in their noisiness. Some of them I can't even hear first crack; some both first and second crack are clearly audible. Unfortunately I believe that if you can't hear it, you can't log it and have to go off time and temperature alone.

Re: Second crack

Posted: Wed 25 Mar, 2020 2:14 pm
by Damian
post your ROR curve, I'll show you FC and SC

Re: Second crack

Posted: Thu 26 Mar, 2020 1:43 pm
by Sam
Hi Damian,

Here is my log file from a my roast of 100 gm Brazil Santos.

I don't know why the RoR curve did not track the profile. It was roast no.8 in back to back roasts.

Thanks,

Sam

Re: Second crack

Posted: Thu 26 Mar, 2020 1:48 pm
by Sam
Hi Damian,

Here is another log file. The first roast of the day.

Sam

Re: Second crack

Posted: Thu 26 Mar, 2020 4:07 pm
by Damian
I think you logged it correctly in the second log, I'm not sure I see SC

I'd call FC in your 0072 log at about 5:10 to 5:20 depending how you call FC, but with a really fast roast like that it is harder to pick, and often more spread out
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Re: Second crack

Posted: Fri 27 Mar, 2020 8:54 pm
by Sam
Hi Damian,

I can usually hear FC its usually between 7:00 and 7:30 minutes for most of my roasts.

It's second crack that I can't hear.

I'll have to analysis my log files more closely.

Thanks,

Sam

Re: Second crack

Posted: Wed 01 Apr, 2020 5:07 pm
by kaffelogic
Sam wrote: Thu 26 Mar, 2020 1:43 pm Hi Damian,

Here is my log file from a my roast of 100 gm Brazil Santos.

I don't know why the RoR curve did not track the profile. It was roast no.8 in back to back roasts.

Thanks,

Sam
Hi Sam
The explanation is the 90-min bug. Whenever the roaster has been on continuously for over 90 minutes it starts to loose its ability to calculate ROR correctly. This meant it could not stay on the profile in your log. The explanation is a bit obscure (catastrophic cancellation of floating point numbers), but there is now a fix available. The fix has been applied to the official release, and also to the two different beta releases currently available. If you update your firmware to the appropriate version the problem will go away in future roasts. See https://kaffelogic.com/community/viewto ... t=144#p902
Cheers
Chris

Re: Second crack

Posted: Tue 07 Apr, 2020 9:37 pm
by Sam
Hi Chris,

I was wondering why the RoR was all over the place.

Will update the firmware.

Thanks,

Sam