PID settings for a WSM 22.5" ?

Anyone using HM successfully with a 22.5 WSM? I should be ready for my first test run soon.

If anyone has some solid PID settings I would like to use them as a starting point.

Here's what I use on my 22.5
B=0; P=4; I=0.02; D=5
Fan pulse; min 10%; max 30%; max at startup
Servo 700 - 2110 inverted

Welcome to the forum, and good to see another WSM user, and 22.5 at that. First things first.......what blower are you using? The stock HM blower? And how is it blowing into the cooker? What direction? A lot of answers needed before we can really help.

I don't have my stock PID settings off the top of my head, but when using the stock blower (combined with a RotoDamper3) I'm capping max output to 40%. With an Auber 6.5cfm blower (my previous setup) I was keeping it capped at 50%. Though the blowers are rated for the same output, the stock def outblows the Auber fan, and furthermore I'm using a Guru adapter on the new setup with an air deflector that blows air towards the bottom of the charcoal bowl, whereas the Auber shoots air upwards at a 30 degree angle or so --- not the most ideal setup, and wastes a tad more fuel.

As far as servo settings, that's something you've gotta figure out yourself. Mine runs 850-2150, but Dave's for example runs in a diff range. All depends on the servo you get, but that's super easy to tune -- you just set a baseline 700-2100 and then min and max adjustments while the HM is set to manual output mode on 0%/100%, until it all lines up.

EDIT: I see you got an RD3, or at least it appears so from your other forum post. In that case, here's what I'm running on mine, and again I'm using the Weber Guru adapter with deflector pointed downwards. Note that unlike Dave's settings, I believe you're supposed to not have the servo on inverted for the RD3.

On the servo "inverted" setting, the RD3 can actually be calibrated to work inverted or not. The only difference is if inverted it will be rotating from top to bottom as it opens, when not inverted it will rotate from bottom to top when opening. I prefer bottom to top, left to right, so I do not invert the servo on the RD3.

One comment/question about your setup Nick... Is there a reason you are using Pulse mode to drive your blower? (perhaps older hardware?) Voltage mode is the newer/better way to run the blower, should be more accurate and cause less noise on the probe readings than Voltage mode. If you have HMv4.2 you can use voltage mode, older HM versions need to be set to Pulse mode.

RalphTrimble said:

One comment/question about your setup Nick... Is there a reason you are using Pulse mode to drive your blower? (perhaps older hardware?) Voltage mode is the newer/better way to run the blower, should be more accurate and cause less noise on the probe readings than Voltage mode. If you have HMv4.2 you can use voltage mode, older HM versions need to be set to Pulse mode.

Click to expand...

Yep mine is a 4.1 model. I had a lot of noise issues on the probe lines when I first got it and you helped me early this year with the RC filter fix, which did wonders. Noise doesn't exceed 10, and usually hovers around 4-6 now.

I'll probably get another HM when the next major update comes out, but I'm in no hurry as this thing works great as is.

OK, with v4.1 you are stuck with Pulse mode on the blower, but the added RC filters are a nice upgrade for the V4.1 board.
Actually, I'm pretty sure I did a how-to thread on upgrading the blower circuit from v4.1 to v4.2 so you can run voltage mode, if you are interested look it up. You have the right MOSFET on V4.1 already, but you need to add the feedback circuit including the coil and a couple other parts.
I think I upgraded my HMv4.0 to v4.1 blower circuit first, then later upgraded it to v4.2 blower circuit and posted the details as I did it.