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  • Alternative PID for Expobar III?

    Howsit?

    I'm wondering if there is a useful alternative PID for my machine. Doesn't make financial sense to buy the same one mine came with since it didn't last long. ( Despite the distributor telling me the machine will last 15 to 20 years. ).

    There was one company that was developing a Android controlled PID, where you had a tablet set up next to your machine and using the touch screen selected your coffee. I contacted the dev and he told me that he lost interest in it because he never received much interest and so he dropped it. Touch Screen PID for coffee machines

    The best mod I've seen for my machine can be found by Googling "Modding an Expobar for increased functionality... and bling!"

    I was hoping for something simple to slot in.


    Any ideas on what would be good to use, other than stock?
    Last edited by BeanMonkey; 29 September 2014, 01:56 PM. Reason: Commercial link(s) removed

  • #2
    G'day BM...

    Have you given any thought to replacing it with something like this? You could then convert your Steam Boiler back to p/stat with SSR control and end up with a more responsive machine overall...

    Mal.

    Comment


    • #3
      Originally posted by Dimal View Post
      G'day BM...

      Have you given any thought to replacing it with something like this

      Mal.
      Cheers Dimal, I check that option out. I like the fact that it comes in green and even white.



      Admin: Sorry about the commercial link. Not sure how Mal's link survived.



      Cool Bananas

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      • #4
        Hi BeanMonkey,

        If your PID has failed due to a faulty transformer (the most common - display is out either all the time, or after being on for a period of time) another option if you or someone that can be easily bribed are handy with a soldering iron, is source a replacement transformer to resurrect your Gicar. I don't have the specs of the top of my head but I think its a 9VDC 1.5VA secondary or something close to that. You can mount the new transformer somewhere else in the case, adequately insulated of course, and then solder some flying leads into the PCB of the PID.

        Changing out the PID is doable, but more work as you will probably end up with a mismatch in chassis cutouts if it anything other than a Gicar unit, as well as incompatible temperature probes (gicar use NTC 47K) and incompatible wiring (gicar switch active to a 240VAC SSR, most PIDs are set up for 12VDC on the SSR output).

        You'll also gain practically nothing in terms of tweakability or temp stability improvements. The Expobar is set up with priority to steam, and the brew channel has no power while the steam boiler is on. As such the default PID is sort of de-tuned to be stable in that situation.

        Comment


        • #5
          Oh thanks coffee_machinist,

          I can test the theory of it being the transformer by using a plug-pack in a temporary fashion. As mentioned in a previous thread when I was trying to sell my machine, I mentioned that the PID appears to work perfectly, except doesn't display the digits correctly. It should have been replaced under warranty, but that was put in the too hard basket, and then it was too late. I did manage to get the machine set to 91 Deg before it got really bad.

          At the time I was selling my machine, I did find somewhere that had the PID for 60 Pounds, and thought that if I did keep the machine, I'd replace it with that. I haven't done this yet, as I was hoping for an increase of 'wow' from the machine, but as you've stated, that's not going to happen.

          I am hand with a soldering iron, so can give something a go.

          Thanks again. This gives me food for thought.
          Last edited by BeanMonkey; 29 September 2014, 01:54 PM.

          Comment


          • #6
            Originally posted by coffee_machinist View Post
            You'll also gain practically nothing in terms of tweakability or temp stability improvements.
            The only thing I actually disagree with mate....

            The PID Units produced by Gicar are very basic units and allow for only very basic customisation of the way one might prefer the brew system to operate. Sure, they have several interlocking options available but as far as a pure PID Controller goes, not for me. One of these days I'm going to be getting rid the system installed in my Diadema and install something that is truly customisable complete with full documentation. Probably just me and my pedantic nature...

            Mal.

            Comment


            • #7
              Hey Mal,

              All true, but maybe I should have emphasised 'practically' nothing. Yeah the Gicars are basic, but controlling the temperature of water in a largeish volume brew boiler (with a probe with fairly slow response) connected via copper to a 4 kg mass of brass where the set temperature is measured, is a pretty basic job. Add to that the fact that any PID in the minore brew scenario is hobbled by being slave to the requirements of the steam boiler, and you get my drift.

              The whole system has a huge amount of lag, but it probably doesn't matter in this application. I'd doubt there would be significant scace-measurable improvements by going to a better quality controller. From a tinkerer's point of view there'd be many reasons to do away with the Gicar and put in a new controller and RTD probe with a faster response, but I'd say if that was the plan you'd also really need to consider downgrading the steam boiler to 1200W and changing the wiring so that the boilers can heat in parallel. Expobar have designed the machine to work a certain way which dictates the pragmatic approach = fix the gicar.

              Comment


              • #8
                Hi BeanMonkey,

                If the display is garbled or missing segments then it's unlikely to be transformer related. The failures I see most commonly are transformers dying prematurely from high heat load. It's borderline impossible to repair / swap out the display so I would then have to revise my opinion above and you may be better off going for a different controller, but you'll have to potentially change the temp probe, wiring and SSR to match the controller.

                Comment


                • #9
                  It's garbled with missing segments.

                  So, one of the options is obviously replace the PID. Most would want to use the Blue PID for the IV, but my thinking is, that because that PID allows you to independently shut down either the steam or group, then it's not a matter of drop in replacement, as wire separation would be required so you can switch the boiler and steam. The III doesn't have this ability, and therefore wouldn't be wired in such a way. Is there a way to use the Blue PID off the IV?

                  Second option is what you said coffee_machinist. Care to devise a kit offering and PM me?

                  Comment


                  • #10
                    The switching off and on of the steam boiler in the IV has nothing to do with the PID, the blue display version is 100% compatible with your machine, its a plug and play 10 minute job.

                    Comment


                    • #11
                      Oh ok. Thought you could disable the steam or the boiler by pressing the Up and Down buttons.

                      Comment


                      • #12
                        I've just seen a PID for $13.60 Delivered. That one didn't come with an SSR, but it goes to show that there's not much in a PID.

                        I'll be getting one for another project. Powder coating oven and a Resin casting oven.

                        Comment


                        • #13
                          Originally posted by BeanMonkey View Post
                          I've just seen a PID for $13.60 Delivered. That one didn't come with an SSR, but it goes to show that there's not much in a PID.
                          Not true mate...

                          You get what you pay for. Industrial/Commercial hardened units use much more reliable internal components and the better ones go through a 'burn-in' cycle before leaving the factory to ensure reliability. Be careful...

                          Mal.

                          Comment


                          • #14
                            Yeah, I know all about quality and price point. Mal, the PID you mentioned was $37.56, so it wouldn't be that much better.

                            My point is that I'm either up for $250 Vs $50 worth of parts that do the same thing. Might even go down the Arduino route and control it via SMS.

                            I like coffee_machinist's idea of lowering the steam boiler so both boilers can run at the same time. I also want to be able to turn off the steam when just making espresso shots, and also be able to do the same with just the steam, for when I'm just making hot chocolates.

                            So, let's explore this further.............

                            So, I need New Boiler Element, New Probe, New PID, SSR etc housing for it.

                            What are the bullet point steps I need to get this all to happen?

                            Comment


                            • #15
                              Originally posted by BeanMonkey View Post
                              Mal, the PID you mentioned was $37.56, so it wouldn't be that much better.
                              That one was only by way of an example, not knowing what your budget was mate. And, for what it's worth, this particular manufacturer makes units that perform well above their price point, so don't be too hasty...

                              Mal.

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