Got the Servo. Now it's Microdamper testing


 
C

Chris D Norton

TVWBB Member
So I'm getting the parts in slowly because I messed up and didn't purchase everything from Steves store for the micro damper.

So I noticed something that I don't know is a part issue or software.

I have the Microdamper servo dialed in at 100% closed and open. Wired up fine and tested continuity with Ethernet cable.

What's strange is, I have the max fan set at 30% by the way, when I test in manual mode only the first move from 0 to 5% it only opens slightly. When I go from 30% down to 5% it's open about twice as much.

The same thing happens from 30 to 25%. It doesn't seem to open as much as the way up.

Could this be the servo I received. Or am I being to anal about it?


Thanks just trying to figure the whole thing out.
 
What do you have set for the Servo pulse duration values and invert output options?

The servo should have about a 90 degree range between open and closed, based on the operation of the micro damper. You see it incrementally open and close with each 5% increase and decrease when in manual mode.
 
It definitely is opening all the way and closing at 0-30%. Fan set is 30% max.

Pulse duration is 680 and 1580.
Invert output unselected.
 
You pulse duration values sound about right, you should have a swing of about 860-890 on the numbers (at least that's what I have on mine). Sounds like you might have a crappy servo, may I ask which brand you have?

Also, I know you are just setting up so maybe you have your fan max at 30% just to keep it quiet. What do you plan to use the MD on? Not sure of a pit where 30% would be appropriate. I use 50-60% on my akorn and 100% on my UDS
 
Chris D Norton said:
It definitely is opening all the way and closing at 0-30%. Fan set is 30% max.

Pulse duration is 680 and 1580.
Invert output unselected.
Click to expand...

Not that it really matters, but I always try to set my servo so it's at about 1500 when half way open. This would mean setting a microdamper (and adapt-a-damper) to about 1050 to 1950. I always start by setting top number to 2000,set the HM to fully open (100%), then install the disc in the closest "cog" to open. Then I adjust the top number until it's perfect. Then set HM to fully closed (0%), and adjust the lower number until it's' fully closed. When done this way, you're setting the servo to the closest "centered" setting, in other words, you have the same amount of travel in each direction of the servo.

Also, remember when testing in manual mode, there can be a 10 second lag between when you set the number and when the servo moves.
 
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I know that I messed up not going to your website first Steve. The servo I received is a cheap one off of ebay and I think that may be the problem as I'm reading more and more.

I have since ordered a TowerPro series SG90, actually 2 of them in a package deal just to make sure. When I get this thing all together I definitely want all quality in there.

The smoker is something that I built from a weber kettle using a 22 1/2 inch restaurant supply pot that I sourced. It's a copy of a Weber Smokey Mountain 22 1/2 I just built it for less as I already had a kettle.

Actually works really well and I can dial in temperatures just as well as the weber and is completely sealed (paid about 125.00 for the upgrade and still have functionality of the kettle.

I was just setting the meter at 30% for testing purposes, because I was having so much trouble with 100% settings not moving very cleanly. I think the servo is a cheap on and will test when I get the new quality SG90's.

When I get the new ones WBegg I will dial in the #'s to around what yours are to make sure that I'm keeping the settings in-line with everyone on this site.

I appreciate all the help and sorry to post so much, I guess I just want it to function perfect. Always been an OCD issue. I'm sure that when I get the thing finally attached I'll prob have a few more questions.

What are you guys using for PID #'s for a WSM 22 1/2? Any suggestions over stock?
 
Chris D Norton said:
I know that I messed up not going to your website first Steve. The servo I received is a cheap one off of ebay and I think that may be the problem as I'm reading more and more.

I have since ordered a TowerPro series SG90, actually 2 of them in a package deal just to make sure. When I get this thing all together I definitely want all quality in there.

The smoker is something that I built from a weber kettle using a 22 1/2 inch restaurant supply pot that I sourced. It's a copy of a Weber Smokey Mountain 22 1/2 I just built it for less as I already had a kettle.

Actually works really well and I can dial in temperatures just as well as the weber and is completely sealed (paid about 125.00 for the upgrade and still have functionality of the kettle.

I was just setting the meter at 30% for testing purposes, because I was having so much trouble with 100% settings not moving very cleanly. I think the servo is a cheap on and will test when I get the new quality SG90's.

When I get the new ones WBegg I will dial in the #'s to around what yours are to make sure that I'm keeping the settings in-line with everyone on this site.

I appreciate all the help and sorry to post so much, I guess I just want it to function perfect. Always been an OCD issue. I'm sure that when I get the thing finally attached I'll prob have a few more questions.

What are you guys using for PID #'s for a WSM 22 1/2? Any suggestions over stock?
Click to expand...

I was curious about the brand because I actually use cheap-o SG90s in my kits, but I haven't had a single problem with them yet. Even if you ordered TowerPro servos, you might get fakes - unless you order from a reputable place such as Hobby King.

It sounds like, from what I'm reading, that you seem to think the fan speed also affects the servo motion. It does not, they are independent of each other. You should see the same motion no matter what percentage your fan speed is.

I have yet to use my HM on my 22.5" WSM, but it's similar enough to a UDS that you should probably start with what I use for my UDS. See photo below. Again, note, your servo pulse duration values will be different...but it should share a very similar range (as in subtract the two numbers and those should be similar).

 
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What happens if you have the servo out of the housing and use 1000 as the low pulse, and 1500 as the high pulse? Does it move 90 degrees between 0% and 100%?
 
So patience it a virtue. Got the thermocouple from Aubrer and the damper works perfect when tested. All good here. Now what am I going to do with 2 extra servos. Haha.
 
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