# DIY PID Silvia Attempt



## prankard

So after a long time of having my Silvia v3 (I think it's been over 5 years).

I think it's finally time that I should mod my Silvia with a PID that I had originally meant to do when I received it.

The auber pid is a bit too expensive and have been searching around at some DIY alternatives and installation guides:





, Auber Kit install instructions

PID on silvia

DIY PID and Steam Brew

However, I have a few questions and a parts list before ordering my first few parts if anyone can help out.

So the parts I think I need are:

PID Temperature Controller

Solid State Relay (x2 if you want steam)

Temperature probe (usually K-Type or RTD)

Wires and connectors

Thermal Paste

Optional Project Box or Enclosure if external install

Optional Insulation on Boiler for temperature stability or internal install

*The Temperature Controller*

*
*

I've been looking around, and the one people are using most are the REX C100. This is great, however I wanted an external installation located in the same place an Auber PID is.









I can't imagine what the REX C100 would look like there, I think it would be too big and might start to impede on cup space.

So I was looking into 1/32 DIN size PIDs. And stumbled onto the XMT 7100 at GearBest.

Someone here has used this successfully for the brew control, but not steam.

Upon looking at the XMT 7100 docs it looks like I can only set one alarm (AL1, AH1). I believe this means it can only control 1 temperature (brew). And to control steam also, I would need a PID that can set two alarms (AL1 AH1 + AL2 AH2). This is my guess as you can wire it up in a few modes, can anyone confirm this?

Does anyone know a 1/32 DIN model (preferably cheap) that can set both brew and steam temperatures?

Note: I also saw the N2006P on ebay that someone else has used on the forum, but I've only seen people use it for brew PID.

*Parts List*



*
*So I think these are the parts I might buyI bought a bit longer cable and more connectors than I needed for this install incase I wanted to PID my friends Gaggia at a later date).

*1x Pid 1/32:*

*
*http://www.gearbest.com/development-boards/pp_47012.html?wid=21

£13.56

*1x SSR*

http://www.ebay.co.uk/itm/SSR-25VA-AC-Output-24-380V-25A-Solid-State-Relay-for-PID-Temperature-Controller-/322059079978?hash=item4afc37912a:g:h3YAAOSwZd1Ve6vY

£3.09

*Project box:*

http://www.maplin.co.uk/p/aluminium-box-12-lf13p

(Should fit, might be tight, but worth a try at the price).

£0.45

*Temperature Probe (RTD PT100 for m4 nut) from forum:*

*
*http://coffeeforums.co.uk/showthread.php?20110-Gaggia-Silvia-Pt100-RTD-sensor-for-PID

£15

*Piggy Back, Fork And Spade Connectors (200):*

http://www.ebay.co.uk/itm/200pc-Assorted-Terminal-Crimp-Connector-Spade-Set-Box-WITH-PIGGY-BACK-/182309516089?hash=item2a727e7339:g:4wkAAOxyTyBSVHqK

£5.30

*14 AWG wire*

http://www.ebay.co.uk/itm/Stranded-Automotive-Equipment-Wire-Hookup-Cable-14AWG-16AWG-18AWG-22AWG-/262256456691?var=&hash=item3d0fb3f3f3:m:moZXNbEUAtER1aqIKGrYJbw

5m = £3.79

*24 AWG wire*

http://www.ebay.co.uk/itm/10-12-14-16-18-20-22-24AWG-Silicone-Wire-Cable-All-Colours-and-Sizes-/281779322997?var=&hash=item419b5b4075:m:mrijirZ6CUsxMSRfkJLPXzA

5m = £2.45

*Total:*

£43.64

Can anyone here confirm that these parts will currently work for a Brew PID? Or have any alternative parts as suggestions?


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## greymda

as far as i know, you use alarm output for steam. and the set value for brew. so you can use 1 pid for brew and steam.


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## cavem01

prankard said:


> So after a long time of having my Silvia v3 (I think it's been over 5 years).
> 
> I think it's finally time that I should mod my Silvia with a PID that I had originally meant to do when I received it.
> 
> The auber pid is a bit too expensive and have been searching around at some DIY alternatives and installation guides:


Not used that exact PID but the rest should be fine!


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## prankard

Thank you both for your responses.

I think you are right, you could use steam with this, I have a quote from another thread along the same lines:

"If you want to, then you can install a 2nd SSR (or diodes or 12V PSU and more complex wiring for a single SSR) and have the PID operate the steam temp as well by using the PID's "Alarm" function. You can then set the Alarm value to (for example) +30C and it'll then control (vaguely - but not as vaguely as the steam thermostat does!) the steam temp and allow you to adjust it using the PID alarm offset.

If you're happy wth the standard steam, then just go with a single SSR and continue to use the standard steam function - and the PID just controlling brew temp."

I got impatient and purchased the shopping list above, and got a few things incorrect (minor things). But it works!

I didn't get a case, the case was collection only from some stores that had it in stock. So I ended up just taping the device to the bottom, it looks fine and blends in well. You only notice the PID is not part of the machine when looking underneath it.

For those that want to follow this as a guide, it was quite easy. The only thing I struggled with was crimping the wires. I didn't have a crimper, and found them quite expensive. So I used pliers to crimp the larger wires, and ended up soldering the smaller wires to the connectors and using electrical tape to clean it up.

All in all, you just need 2 piggy back connectors, and 2 spade connectors. My kit I couldn't find the appropriate piggy back connectors, so I bought some more.

I ended up getting a K-Type thermocouple probe. As my model of my boiler isn't old enough to have the better via the forum that screws on.

The probe was reallly long, I ended up trying it up with cable tidies, which worked OK. But if you can get a smaller one, or cut the wires effectively (I wasn't sure if it would be hard and didn't want to risk it).

I ended up using double sided tape from poundland that I had lying around, which failed after a couple of hours. But buying some M3 branded double sided tape, which ended up being not thick enough. So I used that tape on the poundland thicker foam tape which works (2 weeks running now).

I used some thermal paste, an M5 (i think) nut and bolt and a large washer to fit the SSR.

All in all, the install was good. As a PID, it heats up slower than without (as it's trying to hit the correct temp). And overshots a little between shots. But you can use the brew button to drop the temp by running water through it.

It is however faster at reaching the steam after pulling a shot, as it kicks in the boiler when pulling the shot which I never used to do before.

Anyways, here are some photos.

Some of my pars (2 types of wire, SSR, Pid, Thermocouple, connectors)









The 4 wires, temporarily connected losely before crimping properly (and buying piggy back connectors) and cable tidy/taping.









The Pid from underneath:









Some taping around the back connectors, and wires together.









The front view:









All in all, I think this could be a cheap PID, if you buy the correct parts first time and don't overbuy.


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## greymda

it's not the best idea to have the pid without any cover on. in my case, when i try to get rid of the condensation from the steam wand i have water all over my place including Silvia so... just in case i would cover it somehow.

where did you installed the thermocouple? the fact that now (with a PID installed) it turns on heater when i pull a shot i consider a bad thing (struggling with it myself), so i think i will move my pt100 sensor to the far left bolt. so, where is yours installed?


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## prankard

Hey Greymda,

I don't find the steam wand steam an issue in my case. I always run it off the side into an empty milk jug anyway to stop filling up the drip tray.

However, if I ever run water through the group head after steaming (to drop temp, or clean), there is a LOT of steam which can go near the PID.

I've put electrical tape around the back of the PID connectors to prevent splash of water going near the two power connectors which I was most concerned with. I didn't get a box, because I was finding it hard to get a cheap on. However after some searching I found this one http://www.ebay.co.uk/itm/302090388937 (£4.59) when it arrives in a month I'll install it and for now just be cautious not to use group head over 110c.

I wanted to try and keep all my parts cheap and easy to use. I think anyone could do this mod, except the crimping/soldering the wires barrier.

Now we have 'dremel' + 'crimping' barrier, but would like to see how it is. Perhaps there is a plastic case alternative you could cut easier.

My thermocouple is a k-type (not as described in original post). It's installed on the top of the boiler on the middle screw with a little thermal paste.









I can a video of my temperature dropping and PID turning on when pulling a shot if your interested in comparing.


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## greymda

@prankard , yes, if you can video a single shot would be great. thanks!


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## prankard

greymda said:


> @prankard , yes, if you can video a single shot would be great. thanks!


Sure, here is a video:











Sometimes the boiler clicks and stays on. This time it took a couple of on/off cycles before it realized it needed to turn on. And it hits it's low point at 87c. Usually it's around 90c-95c as it's low point.

I'm having an issue with overshooting after a shot, I need to tweak the settings. I think it's simply due to use rapidly cooling the boiler by running water through it. It's much better hitting the correct temp when turning on from cold. I've only used the auto-tuned values so far and tried tweaking the soulF value on mine (for overshooting).


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## MrShades

Looks good - I assume you only have brew control, and have only one SSR? Where did you locate the SSR - in the base by the pump?

I'm working on a Pt100 sensor that will work on the newer Silvias, but it's taking me some time to develop.... hopefully in the next few weeks I'll have something finalised.

The advantage of a Pt100 accuracy - but also resolution, as the Pt100 gives you access to 0.1 degree C resolution and hence the PID can react (quicker) to fluctuations of +/-0.1C rather than +/-1C.


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## greymda

the fact with the Silvia is it has great thermal stability.

i am trying now to set my PID to just keep the starting temperature steady, and, *after i hit the brew button - to not interact at all*. still struggling with this


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## mplunkett5

Was interesting to read through your thread. I am in the process of setting up a PID on my silvia at the moment. I think I have some wiring problems though and to add to my issues water has stopped coming out of the Group Head


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## prankard

MrShades said:


> Looks good - I assume you only have brew control, and have only one SSR? Where did you locate the SSR - in the base by the pump?
> 
> I'm working on a Pt100 sensor that will work on the newer Silvias, but it's taking me some time to develop.... hopefully in the next few weeks I'll have something finalised.
> 
> The advantage of a Pt100 accuracy - but also resolution, as the Pt100 gives you access to 0.1 degree C resolution and hence the PID can react (quicker) to fluctuations of +/-0.1C rather than +/-1C.


Yes, I located the one SSR (brew only currently) next to the pump at the back. As per





[/QUOTE]

That sounds bad. Probably bad wiring as you say. I'm not an electrician, but do like to tinker. It looks like the brew switch and water switch operate the pump.

Perhaps the brew switch is no longer connected to the pump (rather than the pump being blown). Does the water switch operate the pump still?


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## MrShades

@prankard - Did you get anywhere with the PID tuning values for your Silvia?

I'm having very similar challenges, trying to find values that work well with the Silvia - and allow good recovery without overshoot, and good stability around the set-point.

I'd love to know the P,I,D, SouF and any other values you've found that work well.

Thanks!


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## prankard

Hey Shades,

Currently I'm on:

PID:

1.2, 86, 21

SoulF = 0

Ot = 2

Filt = 0

They work OK (although I think I was tweaking the values a lot). It's more or less the default PID after tuning and then I tweaked some values.

Here are two sets of autotune results:

P 2.4

I 260

D 65

P 1.4

I 86

D 21

I found that decreasing the P value helped, but it didn't go low enough.

SoulF (overshoot), didn't work for me. My guess is because it might be overshooting both ways (increase and decrease in temperature), it will try not to overshoot.

I assume the REX C100 works better as it has settings for overshooting both ways.

But I found a simple trick which makes my system work much better. Basically because we're tuning based on a stable boiler, but then invoking a horrible external change in temperature the PID gets confused. I just turn off and on the power of the unit briefly at it's lowest temperature in a shot cycle. And that makes it not overshoot a lot less.

At a target temp of 101, typically the original overshoot would end up at about 110, but with turning the boiler off and on at it's lowest temperature after extraction the overshoot gets to about 103-5 which works well enough for doing multiple shots at my speed.

My original time took about 5 minutes and now it takes 2-3 minutes which is much more manageable, but typically I run the shot anyway after 2 minutes as usually it's only 2 degrees out.

I did a lot of testing, running the boiler for 10 second shot with no coffee to get to 101 (to get the correct amount of shot water out of the group head), and here were the results, hopefully it will help those that want to really fine tune.

It's hard to measure, in these tests the machine was running for hours, which I don't do in the morning.

Test 1:

PID, 0.14, 86, 21 (soulF 0.2)

Went down to 85

Went up to 106

Settled at 101 after 04:05

Test 2:

PID, 0.06, 86, 21 (soulF 0.2)

Went down to 85

Went up to 105

Settled at 101 after 03:01

Test 3:

PID, 0.03, 86, 21 (soulF 0.2)

Went down to 87

Went up to 104

Settled at 101 after 02:47

Test 4:

PID, 0.01, 86, 21 (soulF 0.2)

Went down to 88

Went up to 103

Settled at 101 after 02:08

Test 5:

PID, 0.01, 86, 42 (soulF 0.2)

Went down to 88

Went up to 106

Settled at 101 after 04:25

Test 6:

PID, 0.01, 86, 10 (soulF 0.2)

Went down to 88

Went up to 103

Settled at 101 after 02:24

Test 7:

PID, 0.01, 86, 5 (soulF 0.2)

Went down to 88

Went up to 105

Settled at 101 after 03:25

Test 8: (Check test)

PID, 0.01, 86, 21 (soulF 0.2)

Went down to 88

Went up to 103

Settled at 101 after 02:23

Test 9:

PID, 0.01, 86, 0 (soulF 0.4)

Went down to 88

Went up to 119

Settled at 101 after way too long...

Test 10:

PID, 0.01, 86, 21 (soulF 0.4)

Went down to 88

Went up to 105

Settled at 101 after 03:15

Good luck with your values, hopefully the on/off trick will help. Post your findings (unlike what I did previously).


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