New Pit Boss blue egg smoker - need to get adapter to mount Micro Damper

RKHanso

TVWBB Fan
Hello - I searched, but didn't see what I was looking for. Maybe I used the wrong search terms.

I just bought a "Big Blue Egg" Pit Boss ceramic smoker/grill from Costco. I need to get an adapter to mount the Micro Damper to this new smoker. I have the standard 1" pipe thread on the micro damper.

Is there something I can easily make for this smoker? I was looking for a DIY solution on the forum but didn't find one. I suppose make a plate out of sheet metal that slides into the inlet damper area and put a pipe out the front that I can screw the Micro Damper on?

I'm guessing that the Micro Damper is powerful enough for the 24" diameter Pit Boss smoker, right? I do have a bit stronger blower, but no servo or housing for it.

Thanks.
 

RKHanso

TVWBB Fan
I think I found something that will work. Hopefully the finish on it won't be a problem - or the finish will burn off the inside.
I had some aluminum trim that's white on one side, brown on the other.
I cut a piece to slide in and will drill a 1" hole and put a pipe in it to mount the Micro Damper on.
I'll keep the left side long so it's easier to put in and take out - like a handle.

 

Matt Fine

TVWBB Member
I have the older black version of the Pit Boss and use the RD3 Rotodamper with it. The stock fan is enough to hold the grill at 650+. Once stabilized at lower temps, say 400 or below, the fan shouldn’t run at all and the servo does all the work.

I made a steel slider door for mine with a round hole in it. The RD3 is mounted to a pipe that goes through a smaller steel rectangle with some felt and rare earth magnets. So, when I want to use the controller, it just sticks on. When done, I can pull it off and bring it indoors.

Pictures posted here:

https://www.kamadoguru.com/topic/34099-controller-adapter-and-lower-vent-seal/
 

Matt Fine

TVWBB Member
I forgot to mention, I have the HM setup to use the damper only from closed 0% PID output up to full open at 90% with the fan coming on from 90% to 100%. Technically, the fan will taper its speed between 5% and 50% as the value increases from 90% to 100%, but the reality is that the output rarely falls in that range. In practice the fan is either on (at half speed) or off with it on mostly just for the initial heat up.

The Pit Boss or any ceramic kamado is efficient enough that you can control it just with the servo, but the blower does help get up to temp faster. I have timed it going from first lighting to 400 in about 8 minutes with the RD3 fan blowing (100% startup mode). That is faster than my gas grill could heat up. It takes at least twice that long to start the Pit Boss with no fan and without a controller it is real easy to overshoot on a “quick” startup, so the heatermeter is a great tool that I use almost every time I fire the PB up.
 

RKHanso

TVWBB Fan
I'm not sure how long this thin piece of aluminum will hold up. But, I have a bunch of it and can make more if it doesn't last. Or, just use some sheet metal that is a little heavier gauge.
I didn't use any nuts to hold the pipe on either side. I made the hole in the aluminum just large enough to thread the pipe in it.
I like the idea of easy removal so I can use the smoker with the damper that came with it when not using the Heatermeter.
Not sure how air-tight it is without trying it out yet. I'll be smoking a turkey in a couple days.

 
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RKHanso

TVWBB Fan
I forgot to ask. I was tweaking my PID settings with my big 64gal homemade smoker I was using.
What would be good PID settings for this smoker? It's a 24" outside, 21.5" inside diameter smoker - 26" tall, I think the same size as an XL BGE.
 

Matt Fine

TVWBB Member
At 21.5” it is actually in between the LBGE (18” grate) and the XL (24” grate).

If you start with the LBGE settings you will be close. I have found different settings work better at different target temps, say 650 vs 250, but there is a wide range of settings that will work well enough.
 

RKHanso

TVWBB Fan
I'm not used to a smoker this small. I wouldn't expect it to take such a long time to get back up to temp after opening the lid. Should it take this long? Almost 20 minutes and still not there.

PID Output Parameters
Proportional 3
Integral 0.003
Derivative 6
Fan output on above 0
% min 0
% max 100
% startup max 60
% Invert output
Servo pulse duration
580
us -
1410
us, fully open at
100
% Invert output
A/C input line noise filter




 

Steve_M

TVWBB Guru
How long was it sitting at 260F before opening the lid? the ceramic cookers take some time to heat soak and tend to recover pretty quickly.
 

RKHanso

TVWBB Fan
Yikes, now I can't get anything above 250F. The blower's been on 100% for a while but the temp has been holding steady at just about 250.
I have the top vent about 1/2 open.
Is the Micro Damper just under-powered for this smoker?

As a test, at 4:13pm today (after this snapshot was taken, below), I removed the Micro Damper and just left the bottom and top vents wide open. I'll see what happens in about 15 minutes and post another graph.

 
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RKHanso

TVWBB Fan
You can see where I removed the Micro Damper at about 4:13 and the temp dipped, then rose a little bit - and then the fluctuation from no temp control.

I must be operating this new ceramic cooker incorrectly.....

 

RKHanso

TVWBB Fan
I put the Micro Damper back on. Added some hardwood to the firebox and it's now up to 275F, but climbing very slowly. The top damper is open wide open (on 3).
This thing is supposed to get up to 625F according to the instructions.

 

Matt Fine

TVWBB Member
You should probaly pack the controller away in a closet for a bit and learn to use the kamado without it so you better know how to use it with the controller. I also would suggest reading some of the Pit Boss forum over at kamadoguru, especially the 2016-17 threads.

If I had to guess, you don't have nearly enough charcoal in it, and you probably have the top vent open too far. The fan is blowing out heat faster than it is stoking the fire. You may need to dial back the max fan output and delay when any fan comes on at all. You really shouldn't need any fan to hit and hold 260, or to recover near instantly when the lid is closed.

The Pit Boss will hold 650 no problem, and I have had mine up well over 900. It takes a full load of charcoal to do that and you need to have the charcoal lit from bottom to top to get the extreme temps. A full load of charcoal only partially lit and with the air controlled WAY back will run 250-275 for 12+ hours. If you get too much lit it will be hard to keep it from overshooting and very hard to cool once it gets too hot. A ceramic grill is like a freight train with undersized brakes. It is slow to build momentum and REALLY slow to shed it. Running under 300 means the top vent open well less than the "1" setting, just a bunch of slivers of maybe 1/16" to 1/32" in each opening. With no servo/controller, the bottom vent only needs to be open about 1/8" as well. It takes very little air to hold the low and slow temps but you do want plenty of excess fuel to hold temps steadily. If you have a good seal on the top and bottom (often not the case out of the box) you don't need to worry about wasting charcoal because you should be able to shut the vents and put the fire out when the cook is over. You may need to add some felt gasket material to get it to seal well. If so look for the original review thread on KG and a couple pages in there are some good descriptions and photos.
 

RKHanso

TVWBB Fan
I did a bunch of traditional "grills" on the Pit Boss without the Heatermeter.
Today, I did low/slow smoke of some ribs and used the heatermeter. The results were not pretty according to the graphs. Here are a couple screenshots.
I have a Micro Damper connected as shown in the fifth post. I did use aluminum duct tape to seal all around where the pipe/aluminum insert into the grill - so the bottom vent should have been sealed off very well. I am using the heat deflector plate and the pit temp probe is above the heat deflector plate, not directly above the coals.
The top vent was closed off completely, or some times, just barely open (like moved 1mm is all).

What do I need to do to get this more stable?



 
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RKHanso

TVWBB Fan
I think I tamed it a bit.
Changed PID to 10, .01, 10
Changed Max fan speed to 80% for the chart below. I later changed it to max of 50% and will see if that helps.

 

Bryan Mayland

TVWBB Honor Circle
Those are some pretty solid oscillations you've got going on there. Looking at where the temperature is dropping, the output is barely on as it is passing the setpoint which would be the easiest thing to tackle. The output on the downslope is the I sum (which appears to be almost nothing, so I'd leave the I constant at 0.02), the P value (which is retarding the output), and the D value (which is trying to stop the value from continuing down). The P and the D are working against each other, so a higher P reduces the effectiveness of the D. I'd take P down to 5, and try a D of maybe 8.

You're almost definitely going to need a max fan of 50% or higher though, the microdamper fan is pretty wee. It does the job but at 20% output, that's 20% of 50% max power and trying to suck air through a 20% wide open damper, it's not a lot of air.

Once you get most of the oscillation out, you might bump up the I constant to 0.03 if you're still seeing it bottoming out to 0% output between the oscillations.
 

RKHanso

TVWBB Fan
I'm going to get a Roto-Damper from Ralph for the new Kamado grill instead. I think it'll be better suited.
The Micro Damper works well with the Weber kettle grill OK though.

I suppose when I get the Roto-Damper, the PID numbers will need to be changed up anyway.

Thanks Bryan, for those numbers and explanation. I tried reading the Wiki to help understand how this whole PID thing works.
 

RKHanso

TVWBB Fan
Doing a test-run with the RD3 instead of the Micro-Damper.
I have to look for leaks because I'm having a hard time keeping the temp down to 225F. Even with the top damper completely closed, and a couple heat-proof gloves sitting on the vents to help it seal a little better - and the RD3 is closed off at the bottom, the temps are dropping really slower than I hoped (I do know that the ceramic smokers will retain heat for a long time and will drop temps slow).

I'll post some more screenshots after the temp settles down.



And my current PID settings:
 

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