Heatermeter 4.3, Damper Servo acting weirdly


 
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WilburBurns

New member
I just received my parts for my damper and I'm trying to get everything working correctly, however, I am having trouble getting the damper to act correctly.

The Damper opens and closed, but at about 90% it becomes erratic and goes beyond it's limits. At other times, the servo chatters, and at other times it doesn't open or close as I think it should.

Currently, I have the fan not turning on until 60%, but the servo should still be modulating the damper in small increments.

Any help is appreciated.

I have used the following for Calibration instructions in an attempt to fix the problem. http://tvwbb.com/showthread.php?627...Build-with-RD3&p=695601&viewfull=1#post695601

Here is a video of what is happening in manual mode.
https://www.youtube.com/watch?v=jc9wolLcD_Y

Any help is appreciated,
Cliff
 
Yup, I know your problem. First off, it's easier to calibrate using the web interface. There you can type into the temperature box 0% or 100% so it jumps to where you are actually looking. Then you can fine tune with 5% and 95%. Moving it manually like you did can cause pauses, as the software doesn't want your damper to jump around so quickly all the time during a normal cook it reacts a little slower when you're only moving it 5% or so.

Now to your problem. I believe this to be the classic case of needing to click the Invert box. Then you'll see more natural motion. Keep in mind that the link you provide with Ralph's directions are for his RD3. Since the Adapt-a-Damper uses the intake shape of the MicroDamper the servo pulse duration values will be a slightly different (and I think smaller) range. So start out with a smaller range, you can always open it up and you'll be able to see the motion more easily.
 
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Interesting. I was unaware that I could type in a percentage in the Web interface to enable or disable the fan/servo.

That being said, I have tried clicking the invert box and that does not appear to be correcting the issue at this point.

Is there calibration instructions for the MicroDamper? A specific range that works well for most?

Cliff
 
OK, After more testing (Trial and Error), I appear to have the settings OK up to about 80%, then it goes weird.

By weird, I mean, goes past what I have 100% set at, and reverses back. I guess as long as I don't need full open, I should never have a problem, but when getting up to sear temps and Pizza temps, I can see it needing to go 100% for a while.

Cliff
 
I don't have a write up this generally isn't an issue (no offence) but I can see where people can get into trouble. First of all with your damper unplugged, make sure you can freely rotate the disc so that you can confirm that it will rotate within the range of the damper being full open and full closed. You want to have a little bit of room on there. Assuming that's all fine, if you find that your are seeing odd actions that means that your servo duration values probably don't make sense to the servo. See the photo below on how the servos behave. Did you take note that when you checked the Invert box that the rotation changed direction? You should also note that when you do that you have to change your own orientation of the values as now being inverted as well. Next time I build a MicroDamper I'll try to make a video on how to do this properly.

90_Servo_Angle_Schematic.jpg

**Note, this is for some random servo so the exact values might not mean squat. THis is for reference only.
 
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Steve_M said:
The servo itself could be bad. They're cheap and plentiful for a reason!
Click to expand...

Certainly a possibility, especially if he's using the MG90 version. But these things act funny if your settings are incorrect, so make sure you figure that out before ripping it out and installing a new one
 
For the Adapt-a-Damper, the stock 1000-2000 settings should almost work as SteveCK demonstrated in his image. The way I adjust is to set the HM, with stock 1000-2000 settings, to fully open, then install the top disk in the closest "cog" to fully open. I then dial in the open setting by adjusting the top number until it's perfect. Then I tell the HM to fully close (0%) and after the servo moves to position, I adjust the lower number until it's fully closed. And yes, it will vary. My numbers on mine are 1150-2000.

Regarding the TowerPro MG90s, yes, if you ordered from E-Bay, chances are it's a cheap chinese copy of a chinese copy. I would suggest buying directly from Towerpro, or buying from a reputable supplier like Mouser or Adafruit.
 
I don't remember if you ordered from me, but if you did I only print the SG90 version because the MG90s have so many problems. Otherwise, the link provided shows it came direct from TowerPro (assuming the seller hasn't changed since you ordered, which happens) so I would assume you are getting a genuine good quality servo.
 
I had the same problem. Servos acting strange exactly like your experiencing.

My fix was to switch out the cat 5 cable.

Using a real quality cable and testing all connections with a multimeter solved all my issues with any servos I had.
 
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