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barneey
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For the bottom holes I normally just use stainless disc stuck down with silicone, water proof and stuck at the same time.
Pot for HERMs
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Vossy1
Landlord.
:lol:
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barneey
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EBay normally http://www.ebay.co.uk/sch/Metalworking-Milling-Welding-/11804/i.html?_from=R40&_nkw=stainless+disc just have a search through for the best offer.
Cheers
Cheers
evanvine
Landlord.
Why do you not use self taping screws and a silicon/rubber/ butol seal?barneey said:
djcorbetto
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I did wonder about using something that could be removed if I needed access, maybe some well nuts underneath?
![BREWING THERMOMETER STICKERS ACCURATELY MONITOR FERMENTING BEER & WINE LIQUID TEMPERATURES 5PCS HOME BREW SPIRITS WINE LCD ADHESIVE [US]](https://m.media-amazon.com/images/I/311DDjo2X3L._SL500_.jpg)
evanvine
Landlord.
Heating elements and wiring/cable don't last forever!djcorbetto said:
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barneey
Guest
With the silicone sealant stuck stainless disc, just get a sharp knife run around the sealant and the disc will come off, simple as that
Just a wee update - I don't have my PID controller fully coded yet, but I do have the temperature being displayed from the probe that is mounted on the HERMs exit, and I can switch on/off the HERMs heating via a button. I used this on a brew on Friday, recirculating for the full 90 minute mash, and manually keeping the temperature within range by turning the HERMS on and off.
I get the feeling that my concerns about thermal lag and response time are unfounded. Even controlling it manually, I can keep the temperature within a 0.4 degree window. There is a very clear relationship between turning the heater on, watching the temperature rise by 0.1 degree, turning it off, watching it overshot by 0.1 degree, etc. So I'm confident that once the PID algorithm is controlling things, it will be very stable.
Also, there was a good correlation between the HERMs exit temperature, and the temperature in the mash tun (as measured by a digital probe).
The end result was a 5% improvement in efficiency, and some very clear wort. And step mashing is a doddle!
I get the feeling that my concerns about thermal lag and response time are unfounded. Even controlling it manually, I can keep the temperature within a 0.4 degree window. There is a very clear relationship between turning the heater on, watching the temperature rise by 0.1 degree, turning it off, watching it overshot by 0.1 degree, etc. So I'm confident that once the PID algorithm is controlling things, it will be very stable.
Also, there was a good correlation between the HERMs exit temperature, and the temperature in the mash tun (as measured by a digital probe).
The end result was a 5% improvement in efficiency, and some very clear wort. And step mashing is a doddle!
djcorbetto
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What pid did you get? I want a good one but not expensive as I need the relays aswell and probes
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barneey
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Glad you got the system up and running 
Yep, your heat exchanger works a treat Barneey, here's a piccy of it in action...
This is the controller that I've built (the workmanship doesn't quite match that of heat exchanger, but thankfully my electronic engineering skills exceed my mechanical engineering skills). I've opted for two boxes bottled together, one for the high-voltage stuff (fuses, SSR, etc), and one for the low voltage (Atmel microcontroller, LCD display, etc), to reduce the chances of :electric: when I'm fiddling around with the low-voltage stuff.
This is the wort return manifold I've been using for a while. The idea came from Eskibrew's stainless wort spreader - this is my bodged-together (and non shiney) version. I prefer it over the spinning sparge arm I had previously.
I had an enjoyable evening testing this with a mash-tun full of water. I don't have a PID algorithm coded yet, just a simple "thermostat" operation (if temp > target then heat=off, else heat=on). This exhibited the expected over-shoot on start-up, or when responding to a large step change. But once it reached a steady-state it was surprisingly accurate. The digital probe reported that the wort temperature exiting the heat-exchanger varied by, at most, 0.15 degrees around the target temperature. The digital probe I had dangled in the mashtun never varied, not even by 0.1 of a degree.
So the system over-all appears to work well - I just need to get the PID code in there to deal with the over-shoot.
This is the controller that I've built (the workmanship doesn't quite match that of heat exchanger, but thankfully my electronic engineering skills exceed my mechanical engineering skills). I've opted for two boxes bottled together, one for the high-voltage stuff (fuses, SSR, etc), and one for the low voltage (Atmel microcontroller, LCD display, etc), to reduce the chances of :electric: when I'm fiddling around with the low-voltage stuff.
This is the wort return manifold I've been using for a while. The idea came from Eskibrew's stainless wort spreader - this is my bodged-together (and non shiney) version. I prefer it over the spinning sparge arm I had previously.
I had an enjoyable evening testing this with a mash-tun full of water. I don't have a PID algorithm coded yet, just a simple "thermostat" operation (if temp > target then heat=off, else heat=on). This exhibited the expected over-shoot on start-up, or when responding to a large step change. But once it reached a steady-state it was surprisingly accurate. The digital probe reported that the wort temperature exiting the heat-exchanger varied by, at most, 0.15 degrees around the target temperature. The digital probe I had dangled in the mashtun never varied, not even by 0.1 of a degree.
So the system over-all appears to work well - I just need to get the PID code in there to deal with the over-shoot.
jim80
Active Member
If it's a mash, does it really matter if it overshoots initially?
I guess it's down to by how much does it overshoot, and how long does it take for it to come back down from that overshoot and get stable.
What are you seeing for those?
If it's a degree or so, and less than 10 minutes I's not be terribly worried about it myself.
I'm interested because I'm about a week or four behind you in much the same process, my HE should be ready next weekend, I've got all the hardware I'll need, know how to plug it together, just turning my thoughts to the software I'll write. maybe.
I'm just tinkering, basically. I can make beer just fine already, but I do like to make things...
I guess it's down to by how much does it overshoot, and how long does it take for it to come back down from that overshoot and get stable.
What are you seeing for those?
If it's a degree or so, and less than 10 minutes I's not be terribly worried about it myself.
I'm interested because I'm about a week or four behind you in much the same process, my HE should be ready next weekend, I've got all the hardware I'll need, know how to plug it together, just turning my thoughts to the software I'll write. maybe.
I'm just tinkering, basically. I can make beer just fine already, but I do like to make things...
I agree with you - an overshoot of a degree or two, for a few minutes, doesn't make much different to the mash. In real use I've found it doesn't overshoot at all, and that is with a simple on/off thermostat algorithm, not a PID algorithm.
In my initial experiments I was shifting a volume of water from 20 degrees to 40 degrees (for example), and the system builds up thermal inertia and overshoots by a few degrees (again, this is with the simple thermostat operation).
Now that I've used it with real brews, I've found it to be quite accurate. This is because when you mash-in, you are already very close to your target temperature. So when I activate the HERMs recirculation, it takes a few minutes for everything to stabilise and then it is already "in the groove". In this state, there is at most 0.12 degrees of overshoot after the element is switched off, and less than 0.1 degrees of undershoot after the element is switch on - so a variation of less than 0.25 degrees (this is all measured at the wort egress from the heat exchanger). The temperature probe I have in the mash-tun doesn't vary at all - not even 0.1 from target.
So I'm in no hurry to implement the PID algorithm, although it is still on my list of things to do. I still think it'll be important when it comes to doing step mashes with the HERMs.
I'm tinkering too - fun, isn't it? :) If you're already making great beer, then HERMs won't make it any better. It might make it more consistent, and if you use a lot of specialised European grains, it may make step mashing a lot easier.
Having said that though, I'm sold on it. Despite taking a fair bit of tinkering to get to this point, now that it is operational, I feel it has simplified and stream-lined my brew day. I don't worry about pre-heating the mash-tun, or mucking around to get my initial mash-temperature right (and then finding there was a hot/cold spot and the temperature has shifted). I under-let, switch it on, and go and do something else for 90 minutes. Unlike other "improvements" I've tried, it hasn't added hassle or complexity, rather, it has done the opposite. It also fits in with my cleaning/sterilising program (I just plumb it in-line when I'm cleaning out the pump).
The wife used if for a brew for the 1st time last week, and her comments were along the same time - it made things simpler and smoother.
In other areas, wort-chilling for example, I've tried to improve things by adding complexity, and then just gone back to the simpler life. I don't see that happening with HERMs...
I'm still getting to grips with it of course, my brew yesterday didn't go according to plan... but that's a different story :)
In my initial experiments I was shifting a volume of water from 20 degrees to 40 degrees (for example), and the system builds up thermal inertia and overshoots by a few degrees (again, this is with the simple thermostat operation).
Now that I've used it with real brews, I've found it to be quite accurate. This is because when you mash-in, you are already very close to your target temperature. So when I activate the HERMs recirculation, it takes a few minutes for everything to stabilise and then it is already "in the groove". In this state, there is at most 0.12 degrees of overshoot after the element is switched off, and less than 0.1 degrees of undershoot after the element is switch on - so a variation of less than 0.25 degrees (this is all measured at the wort egress from the heat exchanger). The temperature probe I have in the mash-tun doesn't vary at all - not even 0.1 from target.
So I'm in no hurry to implement the PID algorithm, although it is still on my list of things to do. I still think it'll be important when it comes to doing step mashes with the HERMs.
I'm tinkering too - fun, isn't it? :) If you're already making great beer, then HERMs won't make it any better. It might make it more consistent, and if you use a lot of specialised European grains, it may make step mashing a lot easier.
Having said that though, I'm sold on it. Despite taking a fair bit of tinkering to get to this point, now that it is operational, I feel it has simplified and stream-lined my brew day. I don't worry about pre-heating the mash-tun, or mucking around to get my initial mash-temperature right (and then finding there was a hot/cold spot and the temperature has shifted). I under-let, switch it on, and go and do something else for 90 minutes. Unlike other "improvements" I've tried, it hasn't added hassle or complexity, rather, it has done the opposite. It also fits in with my cleaning/sterilising program (I just plumb it in-line when I'm cleaning out the pump).
The wife used if for a brew for the 1st time last week, and her comments were along the same time - it made things simpler and smoother.
In other areas, wort-chilling for example, I've tried to improve things by adding complexity, and then just gone back to the simpler life. I don't see that happening with HERMs...
I'm still getting to grips with it of course, my brew yesterday didn't go according to plan... but that's a different story :)
Vossy1
Landlord.
I think you've summed it all up MK Testing a system with water will always give you bigger over/under shoots as a mash is more thermally stable (from my and others experience)
:lol:
Testing a system with water will always give you bigger over/under shoots as a mash is more thermally stable (from my and others experience)T'is the best bit, it gets boring once it's all done and dusted
:lol:djcorbetto
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If I dont want to build my own PID would any off ebay do? or are the expensive ones really worth the extra cost?
The vast majority of folk use the ones of ebay.
If I add up the component cost, mine may be a little bit cheaper. But if I then factor in the many hours it took putting it together, it is a lot cheaper buying one off the shelf!
If I add up the component cost, mine may be a little bit cheaper. But if I then factor in the many hours it took putting it together, it is a lot cheaper buying one off the shelf!
jim80
Active Member
Many thanks for your thoughts on that MacKiwi, much appreciated.
I'm actually just after a smoother brew day, in particular not preheating the mash tun, I'm rather hoping to heat the mash water to strike temperature in there using the heat exchanger, preferably on a timer so it's ready to go when I raise my lazy arse in the morning. Also not having to mess about with hot/cold water to adjust it if I'm off. After that I'm not sure if I'll bother with recirculating, I batch sparge so it's going to get all mixed up when I do that in any case. Also my tun holds temp to less than 1/2 degree over 90 minutes, and that's just fine by my standards. I do recirculate with a pump for a few minutes already, just before running off to the boiler> It's a bit less boring than using jugs to do the same thing!
I don't have particular desire to do step mashes or anything like that, though If that changes then I should be able to.
So your experience is most useful, and very encouraging. I was having some doubts, but it sounds as if I'm a bit more on track than I thought, which is nice.
I was thinking I might have to at least code a simple "stepped" on/off, in that as it hit about 1/2 the overshoot under the desired temperature then start switching the element on and off every five seconds or so to reduce power, but it sounds like I might not even have to get that sophisticated.
I may still do that, or try a "proper" PID code solution, but if it's not required then I do that when I feel like it, and for my own interest - which is nicer!
Cheers,
Jim.
I'm actually just after a smoother brew day, in particular not preheating the mash tun, I'm rather hoping to heat the mash water to strike temperature in there using the heat exchanger, preferably on a timer so it's ready to go when I raise my lazy arse in the morning. Also not having to mess about with hot/cold water to adjust it if I'm off. After that I'm not sure if I'll bother with recirculating, I batch sparge so it's going to get all mixed up when I do that in any case. Also my tun holds temp to less than 1/2 degree over 90 minutes, and that's just fine by my standards. I do recirculate with a pump for a few minutes already, just before running off to the boiler> It's a bit less boring than using jugs to do the same thing!
I don't have particular desire to do step mashes or anything like that, though If that changes then I should be able to.
So your experience is most useful, and very encouraging. I was having some doubts, but it sounds as if I'm a bit more on track than I thought, which is nice.
I was thinking I might have to at least code a simple "stepped" on/off, in that as it hit about 1/2 the overshoot under the desired temperature then start switching the element on and off every five seconds or so to reduce power, but it sounds like I might not even have to get that sophisticated.
I may still do that, or try a "proper" PID code solution, but if it's not required then I do that when I feel like it, and for my own interest - which is nicer!
Cheers,
Jim.
jim80
Active Member
MacKiwi said:
It seems to me that you'd really only make your own controller if
a) You enjoyed doing things like that
b) you wanted to run your own code on it and maybe make it do a bit more than just heat water to a desired temperature (such as adding a timer and pwm control for pump speed for instance)
That's where I am with it, in any case.
I've been getting on just fine with the cheapest chinese PID controller I could find on ebay ( I don't recall exactly, but I think it was maybe 15 or twenty quid?), a solar pump on the bottom of an old fermentation bucket (I call it my "power bucket") with an LED dimmer on it to set the speed. I aim for 60 to 70 litres a brew, by the way, it's about as much as I can lift about realistically and I don't have to brew too often
In fact I looked at that PID and thought there was no way I could build something with the switches, terminals, power supply, casing, sensor and LCD for what it cost me!
They really are cheap, in my opinion.
