Roast Stall D-Roast

[Krish]

Hello there,

First of all, complements of the season to all.

I have had the KL Nano 7 for a little over three months and have been enjoying roasting beans with it.

I experienced a problem today while roasting coffee using the D-Roast profile. Minutes after logging the first crack, the roast stalled. This has never happened before, and I have been roasting with the D-Roast mostly.

Can someone please have a look at this and explain what happened. FWIW, I followed up with another roast, this time using the Firestarter profile which went off without an incident.

Cheers,

[Geronimo]

Hi

I’m not an expert and can only say from my experience using the excellent D-Roast profile is that you had a voltage drop at that point in the roast. Unless you’ve got near perfect 240 volts this can be the result.

If someone turns on heavy current drawing devices like kettles and stove it can be sufficient to drop the power to result in this situation. I avoid turning on kettle and espresso machine, computer when using D-Roast.

When roasting you can look at the live view indicating the power being drawn and if creeping up close to available power can stop the roast and will be slightly lighter but better than a flatline situation.

In my situation our voltage is all over the place and adjust the fan calibration if on limit of voltage. This lowers power requirement, but it is better to customise the profile in Studio.

Cheers
G

[discoaus]

I never had any success with the original D-Roast profile, my main issue was during the cooling period, it wouldn’t actually reach the temp to shutdown so the roasts were continuing for almost 20 mins if I wasn’t watching it. I have now downloaded the Roast V2 for a lower voltage and the profile has worked well so far, I will test the small batch I just did to see if it’s successful. But I could tell by looking at the roast of the original D-roast that the beans had suffered some issues during the roasting phase ( didn’t matter what beans as it happened to multiples)

[kaffelogic]

Hi Krish,

Two things.

First, your roast flatlines. That is, the power reaches the maximum available power, so the power line in the log goes flat. This is something that will happen occasionally with the profile you are using because it makes extreme demands on the roaster. However, in some cases the roast will still 'squeak by' if it has enough power to nearly follow the temperature curve. Which didn't happen because the heater shut off due to a bug in v7.7.8 of the roaster firmware. This bug causes the heater to go off when the roaster flatlines. So,

Second, you need to update your firmware. The update will give you the chance to roast your way out of flatline, but ultimately you may need to alter the profile as other posts in this thread allude to.

Chris