wide colour spread in roasted beans

[Angela]

I was expecting a closer colour match between beans than I'm getting.



This was Steady & Dark 4.8. Filled to 110 grams. And the black ones really are cinders.

PS. forum image link seems not to work - https - perhaps?

Try this - https://drive.google.com/open?id=1fmdoN ... HHh4R-PAMW

PPS
Tried with the lower recommended limit of 90 grams.
https://drive.google.com/open?id=15kDNT ... 7-GUUe-BOV
This seems much more even. Lesson learnt.

[kaffelogic]

As a rule the Kaffelogic should produce very evenly roasted beans. Of course some origins and grades will be more variable than others, but you are correct the photo you show is unacceptable variability. The cause of this is insufficient air coming from the fan. Reducing the load does solve the problem as you have found, but you should be able to roast 120g loads without an issue. I would say your fan needs recalibrating because the speckling you are seeing is a symptom of the fan running too slowly. Your roaster was factory calibrated, but the freight issue you had that required servicing to re-mount the motor has clearly left the impeller clearances slightly different.

I haven't yet completed the calibration instructions, but very simply you need to increase the fan speed calibration number by a couple of points, maybe by four points. Best option would be to increase the setting by 4 points (+0.04) and do a 120g roast and send me the log file of that roast. I can then assess whether any further tweaks are needed.

To put the roaster into calibration mode, turn it on with both - and + buttons held down. Then two clicks of the info button and one of the start button should put you into fan speed calibration. The motor will come up to 16000 RPM, but that is irrelevant just now because you don't have one of our calibration anemometers. Press the + button 4 times, then start button twice, and power off. That should save the modified value with an increase of 0.04 and now that you have bit more air in the system you should be able to roast 120g. Let me know how it goes.

Chris

[Angela]

I hate finding threads sort of left unfinished whenever I search for stuff. So, I thought I'd add the probable conclusion to the above.

When my roaster arrived in the UK the motor had come off its mounting, unknown to me. At first switch on there was a rumbling grinding noise. Being 11000 miles from NZ returning to base wasn't a possibility So I took the machine apart and remounted the motor.

With superb help from Chris it transpired I had lost the air calibration through pulling the machine apart. With a little to and fro with Chris, he was able to check my log files until I had the air calibration about right. Now roasts look like they are expected to.

I must say the machine is built like a tank, but I can't see the heavy gauge of metal used lasting through to the production iteration.

As an aside: this forum seems fairly dead... don't Kiwi's write much?

[kaffelogic]

We are all the strong silent type! Thanks for updating the thread Angela.

I will be posting some guidelines for users to calibrate the airflow of their roasters in the near future - this will help others who either have problems with airflow or want to fine tune.

We have no plans to lighten the build of these machines - they are built with the intention that your grandchildren will inherit a working machine, and that's how we intend to go on.