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Ambex YM-2 is a workhorse
Thought I would share some of my experiences since i have been roasting on my new YM-2 for the last three weeks.

The machine is very sturdy, fires up, ramps up and roasts back to back like a champ. I also use a Hot Top and have become accustomed to using a profiler, data logger. Love that too as I can visually see what has an is probably about to happen. Yet, the YM-2 I purposely bought fully manual. i did this to force me to learn manual roasting.

Its tough, but fun, gets the heart pumping. Everything from ambient temperature, bean volume, charge temp, turn point, when to reduce or increase fire, when to change air venting...it is all a new ball game. Very cool, but be prepared to go through about 50 pounds of coffee to truly learn the nuances.

The other thing is that the machine comes with a Watlow. A small but effective bean probe, it is also manually set and operated but can be upgraded to connect up to data loggers, profilers.

There are a few things I feel Ambex could do to make the machine closer to excellent. Won't list here but if you are considering one and want the nitty gritty, I am willing to share.
Brian King
Roaster / Owner
First Crack Roasters
What Watlow are they including these days?

Agreed, It will get your heart pounding! I am still getting used to mine but am frustrated with the control over ROR. the knob only does so much to slow it down compared to using the pid and constantly setting new target values.
It might be of some help to note (or establish an ideal) time and BT at the turn, at 1st C, and at drop.

Plot the three points and figure out the average Rates of Rise from turn to 1st and from 1st to C.

Then break each leg into two or three parts, based on elapsed time, and figure out whether you want to exceed or fall below the "average" RoR along each part.

That should give you some additional milestones for profiling, which don't require real-time plotting. You'll at least know whether you're going too slow or too fast with time to do something about it -- and that's a helluva lot!

I don't think it makes sense to break damper position, fan speed, or gas flow too fine. If you have three gas settings, 3 fan settings, and 3 damper positions, you're looking at more than 18 theoretical positions (3 x 3 x 3 = 27, but of those, 9 are redundant). Of the 18, maybe 6 will be actually useful.

USRC 1lb Roaster, Chemex+Kone, Espro, Various FPs, Royal Siphon Vacuum, Yama Ice Drip Tower, Bunnzilla, La Cimbali M21 Casa, Ceado E92.
Let me follow up a bit.

First, I just took a roasting class from Mike Perry, and a lot of what I learned is reflect in my post. It's not like I'm a huge, longtime expert. He is though. My apologies if my enthusiasm got ahead of my actual knowledge.

Second, the math was wrong. 3 controllers, each with 3 positions, yields 21, and not 18 meaningful permutations. Only 6, not 9 are redundant.

Third, I'm not suggesting that you break every control into three positions. That was example only. By way of counter example, in the short time I've been using my new roaster, I've established four gas flow, four fan speeds, and three damper useful positions. However -- so far -- there are only five or six useful permutations.

USRC 1lb Roaster, Chemex+Kone, Espro, Various FPs, Royal Siphon Vacuum, Yama Ice Drip Tower, Bunnzilla, La Cimbali M21 Casa, Ceado E92.
Yup, I need to take a look at my logs and see the correlation between for, drop and turning temp. 1st crack depends on the load size due to the probe not making it all the way into the bean mass on the smaller loads.

The primary controller of the for is the pid because the gas is so powerful. The knob really is for finer adjustments and the airflow is still something I have been trying to avoid adjusting since it is yet another variable that may distract me.
firstcrack would appreciate hearing your shortcomings of the YM2.
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