Id really like to PID my Silvia, but...

[gronk62]

.....at the current exchange rate even the cheapest PID kit from Jim is around $492 AUS delivered, which is out of the question at the moment.  

Until the exchange rate improves, a lot, Ive been tryin to come up with a simple work around.

My idea is to try and locate a thermocouple similar to the one Jim uses in his kits and attach it in the same place using the one of the screws that hold the Silvias thermostats to the boiler.

I could run the lead from the TC to a digital thermometer like this one QM1602
This would give me the ability to monitor the boiler/water temp and make "temp surfing" easier with less guess work.

Ok idea, or waste of time?  

[greenman]

Re: Id really like to PID my Silvia, but...

It would give you a reading of the boiler temp as the PID thermocouple is attached at that point.
Jim recommends the PID setting at 109C so you would be able to monitor when the boiler is at that point and pull your shot.
Im thankful I bought mine before the $$$ dived!!!

[gronk62]

Re: Id really like to PID my Silvia, but...

It would give you a reading of the boiler temp as the PID thermocouple is attached at that point.
Jim recommends the PID setting at 109C so you would be able to monitor when the boiler is at that point and pull your shot.

Yeah thats the theory. Instead of a PID unit using the info to cycle the element , it would be really useful info for me to know when the temp was right for a shot. Once I pulled a few shots at different temps I could decide which temp was the "optimal" tasting one and use the thermo to make things 100% repeatable

Im thankful I bought mine before the $$$ dived!!!

I shoulda got with the program early like you

[reubster]

Re: Id really like to PID my Silvia, but...

Gronk,

Its a good idea and much better than flying blind.
You will learn a lot about the machine this way.

With a temp readout you will see just how quickly and how much the temp rises during the heating phase.
I suspect you will only approach 100% repeatable shots with this method if you pull your shots during the heater off/cooling cycle....ie reverse temp surfing.

[gronk62]

Re: Id really like to PID my Silvia, but...

I suspect you will only approach 100% repeatable shots with this method if you pull your shots during the heater off/cooling cycle....ie reverse temp surfing.

Also if the temp is too low I can (and do) flick the steam switch on for a few seconds. With the thermometer I should be able to carefully bring the temp up to about the right spot

[reubster]

Re: Id really like to PID my Silvia, but...

Also if the temp is too low I can (and do) flick the steam switch on for a few seconds. With the thermometer I should be able to carefully bring the temp up to about the right spot

mmmmmmm maybe not quite.

The element is relatively large interms of the volume of water in the boiler, I find if it is held full-on [via steam switch, pid, thermostat etc] for say 5 seconds and then switched off its residual heat will continue to heat the water and the temp will continue to rise.
[A bit like an electric stove top element, switch it off and your eggs will still keep cooking]

So it may be hard to nail: you would have to switch it off prior to the temp you wanted and allow for the rise, plus you would also have to factor other conditions such as what part of the cycle the boiler is in when you started.
This is one of the key differences of a PID, when the PID is operating as it turns the element on and off in little bursts and as the set point is neared, the bursts get smaller and further apart.

But yes, if you played around with it and got a feel for its response you would be able to improve on what you can achieve without the thermometer.
Even if you go a little over your preferred temp the wait for it to drop back wouldnt be too long...from memory the temp drop is about 1C per 20 seconds.

You can still get reasonablly repeatable shots by simply waiting for max boiler temp, running water via the steam wand and watching for the point where the steam and spluttering stops, and then pull the shot.

Obviously, It depends a bit on your definition of repeatable and the level of your palate.
On any machine, good shots must be pulled within a certain temp range [say +/-2C]
With minimal practise the above method can hit this range in a repeatable way.
But many can pick the flavour change of +/-1C [or less] so whilst 2 shots will be good, one may be better than an other.

If you can be bothered and like a fiddle, Id still recommend you fit a thermocouple if you can be bothered as you will gain heaps of useful info on your machine.
Perhaps combining the two methods [flush and temp watch] could be the answer.

[gronk62]

Re: Id really like to PID my Silvia, but...

Also if the temp is too low I can (and do) flick the steam switch on for a few seconds. With the thermometer I should be able to carefully bring the temp up to about the right spot  

mmmmmmm maybe not quite.

The element is relatively large interms of the volume of water in the boiler, I find if it is held full-on [via steam switch, pid,  thermostat etc] for say 5 seconds and then switched off its residual heat will continue to heat the water and the temp will continue to rise.
[A bit like an electric stove top element, switch it off and your eggs will still keep cooking]

Itll be a bit of a learning curve, but surely easier than the guess work of regular Silvia temp surfing without a digital readout.

[gronk62]

Id like to PID Silvia, but this will do for now..

Ok the job is done and it works like a charm.

Thermocouple mounted using the screw for the steam thermostat


Routing


More routing


All finished  

[Dimal]

Re: Id really like to PID my Silvia, but...

Good job G62,

Should make "surfing" a hell of a lot easier and much more consistent, allowing for the differential between the Group and top of the Boiler. Also gives you the flexibility to try pours at different temperatures with different coffees to see what works best with what. Interesting brewing times ahead, eh?

Cheers mate,
Mal.

[vicroamer]

Re: Id really like to PID my Silvia, but...

Did you get the thermocouple from Jaycar Gronk?
[edit]What type of terminal did you use, was it a standard crimp on electrical terminal? [/edit]

[greenman]

Re: Id really like to PID my Silvia, but...

Nice work Gronk, should make life easier!!

[ento]

Re: Id really like to PID my Silvia, but...

Looks like a great way to accurately monitor a reverse temp surf. I will also be able to tell where temp is when I walk up to Silvia i.e. has it just/recently switched off heater element. Then, if I PID, thermocouple can take up full time duty in the soon to be developed roasting division. I like what I see.

[reubster]

Re: Id really like to PID my Silvia, but...

Yeah, really nice work......what they all said!
Keep us posted as to how you go.

[gronk62]

Re: Id really like to PID my Silvia, but...

Thanks all for the thumbs up  

Did you get the thermocouple from Jaycar Gronk?
[edit]What type of terminal did you use, was it a standard crimp on electrical terminal? [/edit]

Yep the thermocouple and digital temp gauge came as a kit from from Jaycar QM1602

I carefully crimped.. well not really crimped, more like gently squeezed a cheapy electrical terminal onto the end of the TC, leaving the tiny wires and temp ball exposed. I just bent it down to touch the fitting. Not really ideal, but Im getting reasonably accurate readings.
Thermostat switches off between 106 - 109 C and switches on again between 91 - 93 C

Its so handy knowing where the boiler temp is at. If its a few degrees too low I just hit the steam switch for a few seconds, wait for the lag to catch up and hit it again if needed to bring it up to shot temp. Currently trialing different temps but on Jim (PID Kits) advice I aim for around the 109C mark, give or take.
My shots have been much more consistent today so Im pretty stoked with the results so far.

Obviously its still a manual temp surfing process, but at least I have a visual of where the temp is at, instead o flying completely blind.

Its a $40 mod, takes less than half an hour to install, and is a perfect "work around" until the exchange rate improves enough to buy a real PID kit.

Jim has been PMing me over the last few days with helpful advice and Im very grateful for his input. A true gentleman!  [smiley=thumbsup.gif]

[gronk62]

Re: Id really like to PID my Silvia, but...

I forgot to say, while Silvia was stripped bare I took the opportunity to sort out some of the excessive "rattles" its had since new.

I repositioned the pump and fittings slightly to move them away from the metal plate that separates the pump cavity from the water reservoir. The braided high pressure supply hose comes in contact with this plate and makes it rattle.

I also put a strip of double sided tape along the full width of the mount for this plate. The plate attaches with 2 screws and the section between the screws rattles against the mount due to the vibration caused by the pump. The double sided tape completely damps this vibration.

End result is a MUCH quieter Silvia. Its almost a purr now instead of a jack hammer