Author Topic: Tipping spoon (new type) - adjusting  (Read 9021 times)

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Offline Fifth Horseman

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Tipping spoon (new type) - adjusting
« on: April 06, 2020, 12:35:24 PM »
This is a quick guide to the new tipping spoon assembly for the VP2.  I've started this as a separate thread so as to make the information easy to find.
Firstly this is not a "how-to" for calibrating a rain gauge, merely how to adjust the spoon especially as it seems Davis think you can't do it.

The spoon assembly is essentially a larger version of the one used in the Vantage Vue ISS

The spoon assembly
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The reed switch - sealed unlike the old type but with the same pin-out
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The magnet and adjusting screw, the closer the screw end is to the magnet the more water it takes to tip the spoon
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Remove this screw and the spoon mechanism comes away from the base
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The adjustment screw on the underside of the mechanism, turn anti-clockwise to reduce the amount of water before the spoon tips (increase rainfall sensitivity) and clockwise for the reverse.
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« Last Edit: April 07, 2020, 12:12:44 PM by galfert »

Offline Mattk

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Re: Tipping spoon (new type) - adjusting
« Reply #1 on: April 06, 2020, 05:16:14 PM »
The design then does defy basic calibration logic in having to pull the mechanism apart, make adjustment, then put it back together again, retest, pull apart again etc etc

Offline mikeym2m

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Re: Tipping spoon (new type) - adjusting
« Reply #2 on: April 07, 2020, 09:10:59 AM »
I made the adjustment without removing the spoon.

Cheers

  :-)

MikeyM

Offline dasman

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Re: Tipping spoon (new type) - adjusting
« Reply #3 on: April 07, 2020, 11:31:21 AM »
is the adjustment from the top or the bottom?
Dave Sommerfed
Peotone Illinois USA
CW7762, KILPEOT1
NWS COOP, CoCoRaHS, Spotter Network

Offline Fifth Horseman

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Re: Tipping spoon (new type) - adjusting
« Reply #4 on: April 07, 2020, 05:23:24 PM »
The head of the bolt is accessed from the underside (after removing the baseplate), however if you are able to grip the exposed thread and not damage it the adjustment  could be made from above.

Offline dasman

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Re: Tipping spoon (new type) - adjusting
« Reply #5 on: April 07, 2020, 09:39:49 PM »
Thank you! I removed it and backed it off 1 full turn. I have been reading 20% or more below NWS COOP and CoCoRaHS guages.

By the way for anyone that is going to make adjustments the head of the bolt was a 1/4 inch socket.
Dave Sommerfed
Peotone Illinois USA
CW7762, KILPEOT1
NWS COOP, CoCoRaHS, Spotter Network

Offline schwab

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Re: Tipping spoon (new type) - adjusting
« Reply #6 on: April 09, 2020, 10:14:38 AM »
Thank you!  I will make an adjustment and appreciate everyone's guidance.

Offline wxmanmhd

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Re: Tipping spoon (new type) - adjusting
« Reply #7 on: May 06, 2020, 07:40:06 PM »
Thank you! I removed it and backed it off 1 full turn. I have been reading 20% or more below NWS COOP and CoCoRaHS guages.

By the way for anyone that is going to make adjustments the head of the bolt was a 1/4 inch socket.

How did your full turn out.  Mine is running short also.  Seems odd to lower the screw to make it tip more often.  Opposite from the tipping buckets. 

Offline dasman

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Re: Tipping spoon (new type) - adjusting
« Reply #8 on: May 06, 2020, 08:24:14 PM »
The full turn put me 15% to 20% high! So I went back a half turn and after a few rains i was low about 10%. So ive been going back and forth with small turns trying to get it closer.
Dave Sommerfed
Peotone Illinois USA
CW7762, KILPEOT1
NWS COOP, CoCoRaHS, Spotter Network

Offline wxmanmhd

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Re: Tipping spoon (new type) - adjusting
« Reply #9 on: May 06, 2020, 08:53:34 PM »
Thank You..I put in my old tipping bucket gauge for now see how things come up with your adjustments.  I was off about 6% in yesterday all day rain of around a inch with no winds on the tipping spoon.
Keith Malakowsky
fmweather.com

Offline GGGG

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Re: Tipping spoon (new type) - adjusting
« Reply #10 on: September 16, 2021, 01:08:57 AM »
Hi,
I have another (and easier way?) I used to adjust my tipping spoon.  All I did was place a piece of Blu Tack about 2mm diameter beneath the spoon near the tip.  This will make the spoon tip more often (ie won't need to fill as much before recording a tip).  This changed it from reading 10% under to 8% over compared to a nearby rain gauge.  I'm in the process of doing some small adjustments.

If the spoon tips too often, then place the Blu Tack on the other side of the hinge.

Blu Tack is a type of plasticine that is used to temporarily stick lightweight posters, paper onto a wall.

Offline mcrossley

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Re: Tipping spoon (new type) - adjusting
« Reply #11 on: September 16, 2021, 04:44:56 AM »
Ha! I use a small piece of Blutack to balance my seesaw buckets! It's been on there many years now. Great minds...
Mark

Offline davidmc36

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Re: Tipping spoon (new type) - adjusting
« Reply #12 on: September 16, 2021, 06:02:08 AM »
.... Seems odd to lower the screw to make it tip more often.  Opposite from the tipping buckets.

This was an interesting post that never was responded to.

The mechanics at play here are as follows:

Raising the screw on the single spoon increases the magnetic force thereby requiring MORE water to make a tip.

Raising the screw on the double tipper "Pre-Shifts" the position (balance) of the tipper thereby requiring LESS water to make a tip.

Offline davidmc36

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Re: Tipping spoon (new type) - adjusting
« Reply #13 on: September 16, 2021, 06:06:18 AM »
.... Seems odd to lower the screw to make it tip more often.  Opposite from the tipping buckets.

This was an interesting post that never was responded to.

The mechanics at play here are as follows:

Raising the screw on the single spoon increases the magnetic force thereby requiring MORE water to make a tip.

Raising the screw on the double tipper "Pre-Shifts" the position (balance) of the tipper thereby requiring LESS water to make a tip.

But the silly thing is; if you want to you can think of it as moving the screw the same direction when viewed from the head end. It is only opposite in relation to gravity. #-o :-P :twisted: [tup]

Offline azchrisf

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Re: Tipping spoon (new type) - adjusting
« Reply #14 on: September 21, 2021, 03:22:50 PM »
Davis says the adjustment is non-linear so they don't recommend it.
Any comments?
Davis Vantage Pro 2 Plus 6163 w/ 8 Transmitters!
Also doing Soil and Leaf 4x
WU: KAZGLEND106 CWOP: FW1398 (F1398) Purpleair: 98793/LAZGLEND8
My setup:
https://www.wxforum.net/index.php?topic=41867.0

Offline Mattk

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Re: Tipping spoon (new type) - adjusting
« Reply #15 on: September 21, 2021, 04:08:37 PM »
Davis says the adjustment is non-linear so they don't recommend it.
Any comments?

Non-linear, Correct. Also any calibration of the spoon design does not meet any sort of proper calibration procedure. Having to remove a device, pull it apart, adjust it (supposedly), put back together then reinstall just doesn't meet a proper calibration practice

Offline box

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Re: Tipping spoon (new type) - adjusting
« Reply #16 on: September 22, 2021, 02:20:16 AM »
Interesting discussion

Given that many users report that it is inaccurate one has to wonder what calibration is actually done by Davis in the first place or is it a lottery performed at final assembly?

Or are users wrong on their assessment as rainfall is very localised? Can you make assessments based on other rainfall sensors nearby but not not actually at the same site?

Seems strange that a reputable manufacturer would produce something that is inaccurate and then make it difficult to calibrate

Or have I missed something?

Offline KA2K

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Re: Tipping spoon (new type) - adjusting
« Reply #17 on: September 22, 2021, 09:03:49 PM »
Yes, rain is very localized. I have seen great variations between stations less than a mile apart. Adjusting tipping buckets to match another stations measurements is an exercise in futility. Don't do it.

Offline kobuki

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Re: Tipping spoon (new type) - adjusting
« Reply #18 on: September 23, 2021, 05:42:14 AM »
Ha! I use a small piece of Blutack to balance my seesaw buckets! It's been on there many years now. Great minds...

I'm about to install this kind of sensor on my ISS. This method looks far easier and more tunable, should I ever touch it. Even if it's not "professional".

OTOH, I'm wondering how much the magnetic force wears off on the long term...

Offline azchrisf

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Re: Tipping spoon (new type) - adjusting
« Reply #19 on: September 26, 2021, 07:24:57 AM »
OTOH, I'm wondering how much the magnetic force wears off on the long term...

This is exactly what I was wondering when they first came out, because we know magnets weaken with time.
I'm wondering if going back to a tipping spoon might be a better idea - but you can't find them anymore. Mine fell off the shelf and broke so all I got is the new tipping spoon.
Davis Vantage Pro 2 Plus 6163 w/ 8 Transmitters!
Also doing Soil and Leaf 4x
WU: KAZGLEND106 CWOP: FW1398 (F1398) Purpleair: 98793/LAZGLEND8
My setup:
https://www.wxforum.net/index.php?topic=41867.0

Offline Mattk

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Re: Tipping spoon (new type) - adjusting
« Reply #20 on: September 26, 2021, 04:31:00 PM »
Some systems include a software means which handles a more practical way of calibration but Davis is not one of these

Offline fkapp

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Re: Tipping spoon (new type) - adjusting
« Reply #21 on: October 26, 2021, 01:48:10 PM »
Need help understanding which way to turn the single tipper screw as mentioned below.

Great pictures, but want to make sure understand what way to turn the adjustment screw.

"The adjustment screw on the underside of the mechanism, turn anti-clockwise to reduce the amount of water before the spoon tips (increase rainfall sensitivity) and clockwise for the reverse."

Is this turn counter clockwise with the tipper mechanism upside down (that is facing the workbench instead of how is facing up when installed on base) with the screw facing up towards the ceiling?

Been significantly lower than near by stations and NWS 3 miles away and have Cocorahs guage arriving tomorrow. I know localized rain but this is consistent lower for me so seems to be the common under report situation with the single tipper.
Thanks so once I determine how much am off (against cocorahs guage) want to be sure to turn screw in correct direction.

Agree is inconvenient need to remove to adjust. Don't see anywhere in weatherlink live to set offset for rain guage so looks to be on device only.
Am going to get the Rainwise likely but probably after winter snow here. So for now want to tune up .

Thanks in advance for the guidance so can do when install nonaero cone with the heater cable mod.
Frank


Offline davidmc36

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Re: Tipping spoon (new type) - adjusting
« Reply #22 on: October 26, 2021, 03:40:41 PM »
"....with the screw facing up towards the ceiling?...."

Move the screw AWAY from the spoon to reduce the magnetic force allowing it to tip easier. So yes, with the screw head hex facing you, turn it left to make it more sensitive, report more rain.

Offline fkapp

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Re: Tipping spoon (new type) - adjusting
« Reply #23 on: October 26, 2021, 03:42:28 PM »
perfect. thanks for clarification

Offline fkapp

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Re: Tipping spoon (new type) - adjusting
« Reply #24 on: October 29, 2021, 09:16:08 PM »
How much does one turn of the screw change measurement?
Say my single tipper guage is measuring 15% low compared to stratus manual Guage next to it, how many turns of screw is needed to calibrate?
Thanks
Frank

 

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