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wind direction is too sensitive

Posted: Tue Jul 14, 2015 8:39 pm
by timwebb2
Hi,

can anyone advise me please on how to modify my weather station, as the wind direction vane is far too sensitive?

I have a Maplin N96GY model.

The wind vane has been trimmed back but still its not made a real difference as my wind direction recordings are all other the place.

Has anyone else had a similar problem and if so what have they tried as a solution?

Can I possibly change some of the Cumulus settings and if so which ones?

thanks,
Tim

Re: wind direction is too sensitive

Posted: Wed Jul 15, 2015 4:39 am
by Super-T
A lot of the windvane problems are caused by disturbed air.
Put the vane 5 metres up on a pole and away from any disturbing influences.

Re: wind direction is too sensitive

Posted: Wed Jul 15, 2015 6:49 am
by steve
timwebb2 wrote:Can I possibly change some of the Cumulus settings and if so which ones?
Fine Offset wind vanes do tend to flap about. If the average direction calculated by Cumulus is not helping to smooth it out, you could try increasing the period over which Cumulus calculates the average using the AvgBearingMinutes setting in Cumulus.ini, see http://wiki.sandaysoft.com/a/Cumulus.ini#Section:_Station

Re: wind direction is too sensitive

Posted: Wed Jul 15, 2015 1:48 pm
by timwebb2
Hi Guys,

thanks for coming back to me with some suggestions.
It is much appreciated.

As it not practical to re-site my weather station to avoid wind turbulence in my garden, as I am surrounded by semi detached houses and trees, I have taken up the option to add a command line to the Cumulus.ini file. This will hopefully help and I will see what difference a 30 min or 60 min average wind direction setting makes.

Thanks again.

I guess this is what you get with a basic weather station, everything else is fine, including temp and barometer settings, as I compare these with nearby sites and these look fine.

Re: wind direction is too sensitive

Posted: Sun Jan 10, 2016 8:53 pm
by Gina
Wind vanes generally "flap about" a lot and what's needed is damping. I'm using magnetic damping in my DIY weather station. A rare earth "supermagnet" is attached to the back end of the vane and rotates within about a millimetre of an aluminium saucepan lid. This damps the wobble really well. Magntetic damping works because if you try to move a strong magnet along a conducting material such as copper or aluminium there is a drag that increases with speed.

Re: wind direction is too sensitive

Posted: Sun Feb 14, 2016 8:42 pm
by ldpahnke
Understand this problem also. I thought about ways to dampen the vane without cutting down on its sensitivity I arrived at the following:

I took apart the windvane and put some silicone oil above the bearing and filled it with some felt and an O ring to keep the oil from leaking out of the bearing compartment. This allows a silicone damped friction on top of the bearing mounting post.

I played with it to allow some slight dampening by varying the amount of felt that held the oil against the bearing causing some friction. This slight friction became my damping method, but I could spin the vane with a heavy breath ie abt 3mph and it would change position without oscillating.

I took a Davis vane and adapted it to my ambient 1080 vane sensor by concentric drilling it and epoxying it to the dome of the ambient vane. I thought the Davis vane would have better aerodynamics. Seems to stabilize it just fine.

This arrangement has tightened (more linear) up the plots on WU and I get very consistent results in accuracy on MADIS daily reports. You can see the plots on my WU Station

http://www.wunderground.com/personal-we ... =KILCENTR4

Take the vane apart at the bearings and see what you can put in to increase friction slightly between the moving and stationary parts in the bearing tube. In my case, a little silicone oil with high thermal stability and some felt worked fine. It doesnt take much felt and oil to dampen it, but playing around with it to find the right amount is the way I did it.
Good luck.!

Re: wind direction is too sensitive

Posted: Tue Jun 06, 2017 2:39 am
by maaw
ldpahnke wrote:Understand this problem also. I thought about ways to dampen the vane without cutting down on its sensitivity I arrived at the following:

I took apart the windvane and put some silicone oil above the bearing and filled it with some felt and an O ring to keep the oil from leaking out of the bearing compartment. This allows a silicone damped friction on top of the bearing mounting post.

I played with it to allow some slight dampening by varying the amount of felt that held the oil against the bearing causing some friction. This slight friction became my damping method, but I could spin the vane with a heavy breath ie abt 3mph and it would change position without oscillating.

I took a Davis vane and adapted it to my ambient 1080 vane sensor by concentric drilling it and epoxying it to the dome of the ambient vane. I thought the Davis vane would have better aerodynamics. Seems to stabilize it just fine.

This arrangement has tightened (more linear) up the plots on WU and I get very consistent results in accuracy on MADIS daily reports. You can see the plots on my WU Station

http://www.wunderground.com/personal-we ... =KILCENTR4

Take the vane apart at the bearings and see what you can put in to increase friction slightly between the moving and stationary parts in the bearing tube. In my case, a little silicone oil with high thermal stability and some felt worked fine. It doesnt take much felt and oil to dampen it, but playing around with it to find the right amount is the way I did it.
Good luck.!


Hey, great suggestion! I'd say this is the way to go. I just have one question. In the profile picture of your PWS in Wunderground I can see that the wind vane is not the stock one. Why did you have to change it?
Cheers

Re: wind direction is too sensitive

Posted: Sat Jun 10, 2017 5:54 pm
by mikechristelow
I appear to have received some help damping my wind vane :lol:

Re: wind direction is too sensitive

Posted: Mon Jun 12, 2017 9:21 am
by mcrossley
A turntable viewing platform!