If we keep badgering you to post, that's an excuse to tell your wife isn't it? "Oh those crazy folks at HB are making me work on my machine."

Seriously, I would like to know more about the temperature profiling bit, and especially the automation thereof.

Sean, this is incredibly impressive work. Thanks for sharing with us. I wanted to ask you about the two lines coming into the solenoid/needle valve boss. You said:

lennoncs wrote:The lines are for sense and feedwater.

I assume that means one is a cold (or warm) water line pressurized by the pump. Is the sense line just a 1/4" OD thermocouple? I'm curious how you've positioned it in relation to the mix valve inside the boss.

Now that I am crippled from 3 days of sunrise to sunset skiing (thereby also crippling my honey-do usefullness )

"The Block" as the valve block under the 3-way valve is so affectionately known as, consists of the following equipment;

2 servo actuated needle valves
valve #1 is used as a variable orifice from 0 to 1.42 mm
this is used to control backpressure and maximum flow for the system

valve#2 is used as a variable orifice from 0 to .61 mm
this valve is used to meter the mix water for temperature control.

2 fluid ports
Port #1 is pressure sense for the grouphead
Port #2 is hot water feed for temperature mix

1 thermocouple
a very finewire thermocouple with a ceramic coating is inserted into the water stream after the mix valve to provide feedback of the final water temperature.
Due to the response of the thermocouple, some approximations are made for water temperature control but so far it has been consistent.

the variable brew orifice has not seen much closed loop control development as of yet but a simple scheme of valve positioning based brew pressure has helped controllability of brew pressure significantly.


Sean

My kind of thread this is similar to a project I've started some time ago, yet never finished. It's back on my to-do list, for when the ZR71 grinder job is finished (whenever that is). I'm watching with a lot of interest (don't think temperature profiling has been done before like thsi) and jealousy (all the precious control related parts:))

Mind if I ask what uC you are using for this? Also all those parts cost a fair bit of money, are these spares from other jobs or do you have a really good friend somewhere in the control industry?

All the best with the project!

Regards,
dsc.

Great project!

dsc wrote: Mind if I ask what uC you are using for this? Also all those parts cost a fair bit of money, are these spares from other jobs or do you have a really good friend somewhere in the control industry?

Howdy,
at this time I have not migrated anything to a smaller platform, in fact, I may stick with the control I have.
My current machine is using this platform;

It is a Mini ITX Form-factor computer running Labview.
all IO and the power supply stack on the right end of the 18cm X 25cm baseplate
The processor is a 54W Corei3 4340.
there is an 128GB SSD that is attached to the bottom of the motherboard.

Is it the smallest
No, But, I spent a large amount of time on a previous machine making everything compact "just in case" I took the machine somewhere.....I have never moved the machine, let alone take it somewhere.

Is it the lowest power solution
No, but neither is 3,000W of heaters in the boilers. total power consumption for the control is a bit less than 80W-90W with all controls active.

Is it reliable
Hasn't failed yet, and it's 11 year old predecessor is still running strong.

will the machine run without it?
Sure will, part of the shutdown process includes the following.
parking the temperature control valve in the Block fully closed
parking the variable orifice at .6mm
handing over control of the brew group paddle to the brew pump PID control
handing machine logic over to the steam/water supply pump PID control
Brew temp and steam pressure are controller by a pair of fuji controllers anyways,
so nothing much changes there except the loss of adjustments via touchscreen.

the 2 controllers for the pumps have enough codespace for machine control, they are just a bit hampered on IO, so the machine control just reverts to a fairly standard machine with the exception of paddle controlled brew pressure. technically, the controllers are capable of more but I just haven't let that float any higher on the A list items....it is kinda Z list at the moment

What the control gives me is the ability to quickly develop refined, intuitive user interfaces and machine controls without the hassle coding for a target device that I am always having to deal with IO and screen limitations. I used to code in assembler, Forth and a few obscure languages for imbedded data collection systems....I still write for imbedded systems on my daily job and didn't feel like doing it for home.
Besides, this gives me that ability to use a very high resolution touch screen for some nice graphical interfaces.

I am still working on the user interface but one of the interesting side effects of using the platform is that It supports multiple screens and has Bluetooth / WiFi....so....It has been used as a media server for my wife in the Kitchen...music,recipes, etc. my only stipulation is that her media resides on an external drive and I had to clarify the other day that "multi touch" does not mean 2 people on 2 different touch screens at the same time.


I figure if compactness starts to be an issue, I can always package the code and move it to a dedicated platform...but the machine is not that much bigger than the electronics boxes of some commercial machines already.



As to parts, Yes, they are a bit spendy.
Yes, I have friends
Yes, many are leftovers from past machines
Mostly though, I am only making 1 machine for myself so I don't have to worry about margins, availability, blah blah blah.



The latest on the mechanical front is that I am welding the stainless frame for the machine to sit on, i needed to get it raised up off the bench to install pumps, trays, flowmeters, etc.
Not a part of the process, I have been looking forward to because I don't like welding stainless(hex-chrome)

I will post a photo of the machine with the new frame and pumps mounted.


Cheers,
Sean

Cheers Sean, I wasn't expecting a Mini ITX PC with LabView, although I can understand why this was chosen over say a PIC or something similar. I've used assembler on a PIC for a grinder project before, then switched to C for the current grinder job (way way quicker), but even that is limited or complicated for stuff like touchscreens etc. As you say it's a one-off, so even if the costs go up dramatically due to expanding requirements, it's not a biggy.

lennoncs wrote:No, But, I spent a large amount of time on a previous machine making everything compact "just in case" I took the machine somewhere.....I have never moved the machine, let alone take it somewhere.

The 'just in case' factor is always fun:) especially when you spend a lot of time designing something 'just in case' and miss other pretty important bits in other areas.

Good luck again and looking forward to seeing the beast in action!

Regards,
dsc.

What tools can you recommend for dealing with the copper pipes, like bending and flaring for the fittings? I haven't done much with my Elektra project in a while but I want to get going on that, I'm just not experienced in making the pipes.

I have, in fact, I have one.
It would do the job, I just don't feel like redoing all the code.
I am just lazy that way

Sean