Controlling RD3

My buddy just got done putting my HeaterMeter w/ RD3 together for me yesterday. I thought I was computer savvy until I started getting into this thing. I guess I have a couple questions regarding this build:

1. Can the blower and servo be independently controlled? I noticed that if my HM says 50% the servo is at 50% and the fan is also at 50% (I think). I know I can adjust the blower min & max.

2. Where in the config page can you change from "Blower Mode" to "Damper Mode".

I have looked through the 50+ pages in regards to the RD3 but can not find what I am looking for. My buddy that built it said I am looking into this way to much. He said plug it in and let it do its thing. I just know when doing low and slow cooks on my Primo Round that I barley have both the top and bottom vents open. With that being said:

3. If the damper is open lets say 5% to maintain 225, will my fan also be running at 5% or does the HM know to keep it off?

I honestly have no clue what some of the stuff on HM wiki page even is. All I know is, I am learning a lot!!

I'm very new to this as well (Primo Oval XL also), but my understanding is that if you want the damper open and the fan off when only small changes are needed, just set the "Fan out: on above X%" to some value that makes sense for your setup. For example, I'm playing with the HM right now in my office attached to the MicroDamper. If I set the setpoint to 80°*(it's 70 in my office) and have the Fan Output: "on above" to 40% - the damper is 40% open and the fan is off. If the setpoint is changed to 250° (that would be one hot office!) the damper opens up full time and the fan is on full speed. So, small differences between the current temp and the setpoint will use the damper only but larger differences will use both if you play with that "on above X%" factor.

Ken B said:

I'm very new to this as well (Primo Oval XL also), but my understanding is that if you want the damper open and the fan off when only small changes are needed, just set the "Fan out: on above X%" to some value that makes sense for your setup. For example, I'm playing with the HM right now in my office attached to the MicroDamper. If I set the setpoint to 80°*(it's 70 in my office) and have the Fan Output: "on above" to 40% - the damper is 40% open and the fan is off. If the setpoint is changed to 250° (that would be one hot office!) the damper opens up full time and the fan is on full speed. So, small differences between the current temp and the setpoint will use the damper only but larger differences will use both if you play with that "on above X%" factor.

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That was exactly what I was looking for. I wasn't sure what that setting was. Thank you! So do you leave your fan 0-100% and start up at 100% or do you still set a max to let's say 50% or something.

The stock fan for the RD3 moves a good amount of air. I believe most people run it with the max % throttled back quite a bit. You have to figure out what works best for your cooker and the temperatures you want to maintain.

I run my PBC with no fan at all. Just a damper. I feel the only time I might want a fan would be to ramp temperature changes up really fast. But that's not a big issue for me.

I'm so new that I haven't cooked yet with the HM and MicroDamper. I just received the printed parts yesterday for the MicroDamper. I'm doing a test cook right now, and so far so good. 100% startup, 80% at max and 15% for "on above". I'm testing at 200°, 225°, 275° and 350°. The biggest question I have is what to do with the the top vent. I've kept it at about. ¼" to ⅛" open.

If I'm only using the damper, then I'm going to set my top vent where I normally keep it for low and slow. And that is barely open. I might even set my "on above" to more like 80%. I don't think the fan is necessary except for higher temp cooks. But then again, I haven't even got a chance to try it on the grill. It's been raining all damn day.

I'll post my graphs shortly but the best part of the test cook and the benefit of the fan was the quick transitions. From my MAP gas start to 200° was 10 minutes. And quick transitions to 225, 275 and 350. Without the fan, the MicroDamper couldn't let in enough air as a wide open bottom vent would.

I kept the top vent at ⅛" for 200°, ¼" at 275 and opened it to over an inch during my 350° test. I was exceptionally happy with the results. Charts soon.