Keg Weighing System

[punkin]

I'm trying to find the you tube vids i saw linked on here ages ago of what i think was a kiwi guy who installed scales in his keezer and could measure how many pinys he had left in a keg.

I tried a search and came up with nothing, does anyone (most probably) have a better memory as to where it may have been and could in a perfect world provide link to the thread or the video?

 

[MastersBrewery]

check the arduino thread system was built by Zizzle, took him a good while to get it going though, think he used sensors from a bathroom scale them amplified the signal. Will see if I can find the thread. Tutorial required if you build it though!!!

 

[MastersBrewery]

ok I was wrong but here's the linky http://aussiehomebrewer.com/topic/68935-keggerator-upgrade-beer-level-indicator/#entry973603

 

[punkin]

Excellent thank you. I seem to recall he did a good job of a tutorial in the original post?

Not gunna build it, would make it too easy for her to track what i drink in a session and would probably scare the life out of me too.

 

[PeteQ]

I've thought about this idea for a while, unfortunately I'm not an electronics and/or IT genius so I'm slowly getting bits together for this project with coding help from a mate.

This is definitely worth a look if you haven't seen it already http://kegbot.org/

 

[punkin]

This looks terriffic. Does anyone here run this?

 

[MastersBrewery]

I've thought about this idea for a while, unfortunately I'm not an electronics and/or IT genius so I'm slowly getting bits together for this project with coding help from a mate.

This is definitely worth a look if you haven't seen it already http://kegbot.org/

those flow sensors look like they could be used else where in the brewery too, food grade and good for 90c+ only thing is the price at $60 each could get a little pricey.



Edit: typo

 

[Nick JD]

Heh heh, keg bot.

I was thinking two weldless fittings on the top and the bottom of the side of a keg with some beer line between them. But I'm a simple chap.

 

[MastersBrewery]

I think it's just easier to have a few full kegs as back up. Kegbot looks like it's doable well atleast for some of our more tech minded, but the board they sell only handles 2 taps on a normal arduino to go to more Taps requires you to have a board made (they have the files freely avaliable), and an ardunio mega, software would be the same as the code can handle 6 taps. All that I could do, I just wouldn't know where to put what parts once I had the boad made. I have 3 Taps so I recon $100 a tap, the other positive would be once put together and sorted adding a tap would be $60 + postage for the flow metre.

 

[punkin]

Lost my reply. Somone on another forum pointed me to this system.

At least it's plug and play and whole lot less expensive. You loose the accuracy and all the extra features though.

Not sure it's worth the effort if it's out 10 glasses a keg.

http://www.keg-meter.com/

 

[Edak]

I think it's just easier to have a few full kegs as back up. Kegbot looks like it's doable well atleast for some of our more tech minded, but the board they sell only handles 2 taps on a normal arduino to go to more Taps requires you to have a board made (they have the files freely avaliable), and an ardunio mega, software would be the same as the code can handle 6 taps. All that I could do, I just wouldn't know where to put what parts once I had the boad made. I have 3 Taps so I recon $100 a tap, the other positive would be once put together and sorted adding a tap would be $60 + postage for the flow metre.

Wait.. I thought that you could have 4+ taps with a single Arduino uno. Where did you get that info?

 

[MastersBrewery]

Wait.. I thought that you could have 4+ taps with a single Arduino uno. Where did you get that info?

Read through the forums a little, One keg board and an arduino uno can do 2 taps max, each keg board can take 2 coasters max, and each coaster can run 2 taps, but apparently the coasters were only for convinience of wiring. It comes down to the number of interupts avaliable on the arduino. Now you can hook up as many arduino's with kegboards up to the same system as you like (just rename server side). The Arduino Mega (and they reccomend the AT128) can handle upto 6 taps but as stated previously you would have to have the board made up yourself. Note the server for keg bot does not run on the arduino it requires a seperate linux system, and if you want the interface obviously a cheap Andriod tab. Still got a bit more reading to do, I have nowhere near the arduino experience you do, you might be able to get your head around it a little better. If I were to do something like this it would be a few years down the track, so hopefully one of you guys get one up and running and I can pick your brains. Over all it seems well documented and the forums provide a little more indepth info.

Edit:
Ummm .... pics or it didnt happen, nah bugger that, anyone does this and they should do a tutorial very cool bit of kit

 

[dmac80]

If you're after accurate volume measurements, i think Zizzle's method of weighing the keg would be more accurate than flow measurement.
When you try and totalise a flow, if there are any inaccuracies in the flow measurement these are 'amplified' by the totalising. The error then becomes quite noticeable.
Cheers
Dan

 

[dougsbrew]

worth considering? linky - http://www.ebay.com.au/itm/Digiflow-Digital-Flow-Meter-count-up-total-Water-Measure-in-Gallons-GPM-56-cable-/350693774919?pt=LH_DefaultDomain_0&hash=item51a6fa5647

 

[dmac80]

There doesn't appear to be any accuracy data on that listing doug, maybe ask the seller. Then you can work out your maximum error over the volume of a keg.
Cheers

 

[punkin]

That's the one in use by people on a forum where they are measuring flow of cooling water. They are very happy with the unit, but accuracy is claimed to be +- 5%.

Looks like if you want usefull accuracy you need to pay the bickies.

http://www.digisavant.com/PDF/DF0671L-Spec.pdf

 

[MastersBrewery]

If you're after accurate volume measurements, i think Zizzle's method of weighing the keg would be more accurate than flow measurement.
When you try and totalise a flow, if there are any inaccuracies in the flow measurement these are 'amplified' by the totalising. The error then becomes quite noticeable.
Cheers
Dan

Zizzles system is measuring in pints, and using amplifiers to boost signal, the keg bot can measure in mls with accuracy +/- 1% straight off the shelf, if the calibrated to the system +/- 0.3% so that'd be like 60ml over a keg. The other thing is comparatively keg bot is plug and play. Zizzle has awesome coding and electronics skills that make the rest of us look like dopes, and it took him a year, so for someone like me to build a unit to do what these systems do from scratch would be counter intuitive, why would I reinventing the internal combustion engine with no idea of egineering.

I think zizzles system is friggin awesome, but I couldn't replicate it.

Keg bot is also awesome and something with help I could implement, it also has a few extra nifty features already built in.

 

[Edak]

Read through the forums a little, One keg board and an arduino uno can do 2 taps max, each keg board can take 2 coasters max, and each coaster can run 2 taps, but apparently the coasters were only for convinience of wiring. It comes down to the number of interupts avaliable on the arduino. Now you can hook up as many arduino's with kegboards up to the same system as you like (just rename server side). The Arduino Mega (and they reccomend the AT128) can handle upto 6 taps but as stated previously you would have to have the board made up yourself. Note the server for keg bot does not run on the arduino it requires a seperate linux system, and if you want the interface obviously a cheap Andriod tab. Still got a bit more reading to do, I have nowhere near the arduino experience you do, you might be able to get your head around it a little better. If I were to do something like this it would be a few years down the track, so hopefully one of you guys get one up and running and I can pick your brains. Over all it seems well documented and the forums provide a little more indepth info.

Edit:
Ummm .... pics or it didnt happen, nah bugger that, anyone does this and they should do a tutorial very cool bit of kit

Yeah, it appears you are right. The website is misleading but the forums describe it perfectly. For four taps you have to either:
1. buy two arduinos, two keg boards and two coasters
2. buy arduino mega, design own keg board and two coasters
3. re-design the wheel

Personally that sounds like too much hardware.

If you're after accurate volume measurements, i think Zizzle's method of weighing the keg would be more accurate than flow measurement.
When you try and totalise a flow, if there are any inaccuracies in the flow measurement these are 'amplified' by the totalising. The error then becomes quite noticeable.
Cheers
Dan

Zizzles method is great but it requires a LOT of work:
* Build custom floor for the fridge to which you can bolt the measuing apparatus
* Build the measuring plates
* Ensure that your floor and plates aren't going to get destroyed by condensation/liquid damage
* Calibrate each measuring plate
* Build the amplification circuit
* Ensure shielding is strong
* Much more wiring


I am thinking that I will use a purpose-built data logger which can handle everything and has a webserver in-built. I already have a suitable solution with multiple high-speed counters and inputs for up to 5 load cells, but I still like a proper, customised solution.

 

[dmac80]

Zizzles system is measuring in pints, and using amplifiers to boost signal, the keg bot can measure in mls with accuracy +/- 1% straight off the shelf, if the calibrated to the system +/- 0.3% so that'd be like 60ml over a keg. The other thing is comparatively keg bot is plug and play. Zizzle has awesome coding and electronics skills that make the rest of us look like dopes, and it took him a year, so for someone like me to build a unit to do what these systems do from scratch would be counter intuitive, why would I reinventing the internal combustion engine with no idea of egineering.

I think zizzles system is friggin awesome, but I couldn't replicate it.

Keg bot is also awesome and something with help I could implement, it also has a few extra nifty features already built in.

The listed 1% accuracy doesn't specify if it is 1% of measurement or 1% of full scale (which can often be the case). 1% of full scale will give a much larger error. Having said that, the flow meter listed looks a good bit of equipment.

Yeah, it appears you are right. The website is misleading but the forums describe it perfectly. For four taps you have to either:
1. buy two arduinos, two keg boards and two coasters
2. buy arduino mega, design own keg board and two coasters
3. re-design the wheel

Personally that sounds like too much hardware.


Zizzles method is great but it requires a LOT of work:
* Build custom floor for the fridge to which you can bolt the measuing apparatus
* Build the measuring plates
* Ensure that your floor and plates aren't going to get destroyed by condensation/liquid damage
* Calibrate each measuring plate
* Build the amplification circuit
* Ensure shielding is strong
* Much more wiring


I am thinking that I will use a purpose-built data logger which can handle everything and has a webserver in-built. I already have a suitable solution with multiple high-speed counters and inputs for up to 5 load cells, but I still like a proper, customised solution.

I think both of you guys have kind of missed my point, i'm not saying to go out and try and build Zizzle's setup, but from my experience working on instrumentation in industry, it's more accurate to measure the product in a vessel than to try and totalise the flows in or out.

The kegbot certainly does look like a flash bit of gear though!

Cheers
Dan

 

[Nick JD]

What about a temperature sensitive sticker that goes down the side of the keg. You open the fridge for a minute, and you can see where the fluid level is due to the empty part of the keg warming faster than where the beer is.

50c per keg.