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[Guide] Sunbeam Torino EM8000: Reducing the pressure with a dimmer

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  • [Guide] Sunbeam Torino EM8000: Reducing the pressure with a dimmer

    Let me preface this to say, I'm a big fan of my Sunbeam Torino.



    I've had my Torino for about a year now. At the time, I read the reviews talking it down before I bought it but didn't have the bench space for a BDB (and my SO veto'd it based on looks and size).
    I also got it for about AUD 1K, much less than the original RRP. I know a lot of the other Torino posts are in the "pointy end" section, but as I didn't pay nearly that much for it I think it fits here.For the price I think it's the best looking machine that has all the conveniences like dosed shot buttons, pour timer, quick startup etc.


    Right from the start I've been very happy with it in every way bar one: the pressure is way too high.


    I don't know if the pressure gauge on the front is accurate (I don't have a separate grouphead gauge yet) but it says my pour pressure is usually 12 - 14 bar if I want a brew time in the 20-30 second range.
    Grinding/packing the grounds lighter to reduce the pressure results in a pour time in the 10 - 20 second range with flavourless coffee.


    A while back I got the bottom of my old EM6910 portafilter machined out to make myself a naked portafilter.
    Using this gets heaps of squirting all over the place, it makes a huge mess. The puck always looks pretty channelled too, supporting my belief the pressure it too high.


    Early on I found the post noting the lack of OPV in the torino:
    https://coffeesnobs.com.au/brewing-e...tml#post569653
    as well as mention that modding the machine to add one improved it significantly:
    https://coffeesnobs.com.au/brewing-e...tml#post570264


    But this does sound somewhat difficult, I don't have the required plumbing supplies hanging around and finding the array of fittings to suit felt too hard, I'm not versed in sizes, connector types etc.


    Then I found out about adding a dimmer to the pump: https://coffeeforums.co.uk/topic/791...dimmer-switch/


    I'm much more comfortable with electronics and electrical devices, so this was right up my alley. It's also easily reversible; it doesn't require and cutting / modifying of the machine internals so if I don't like the results, or if something goes wrong and I need to send it in for service, I simply open it up, unplug the dimmer, plug the pump back in and no one's the wiser.


    The Dimmer

    This is an off-the-shelf light dimmer:


    Note its label says it's a leading edge dimmer.
    There's basically three main types of dimmer on the market:
    * Leading Edge
    * Trailing Edge
    * Universal


    Leading Edge
    The original / oldest type of normal light dimmers. For each cycle of the AC power waveform these take a chunk off the start, leaving only the final part of each waveform. These typically don't work well with modern electronic and LED based lighting systems, driving the development of the newer generation of dimmers


    Trailing Edge
    As the name suggests, these leave the start of each waveform intact, chopping out the back instead. These work much better with most LED and electronic power supplies so have risen in popularity. However they don't work well eith magnetic or inductive loads due to the back emf from chopping the waveform under full load. This will often damage the dimmer if used to drive these, as well as possibly the load.


    Universal
    These include some version of smarts / circuitry to attempt to determine what kind of load is connected and choose between Leading and Trailing edge mode automatically.


    My Dimmer
    Note in the picture above, my dimmer is leading edge. **This is very important.** The vibration pump in the espresso machine is basically one large electromagnet, pulsing on and off. As such it's very much an inductive / magnetic load so a trailing edge dimmer is not appropriate.


    The first dimmer I tried was a newer/cheaper universal one, a DETA 6032 I got from Bunnings (Australia) as part of a dimmer wall plate: https://www.detaelectrical.com.au/detail-2/?de=6130B
    The dimmer itself had a translucent purple housing.


    I initially wired this up, powered up the coffee machine and pulled the handle to start the water flowing. I heard relays all click, but the pump did not start. I tried the dimmer connected both direction, on both pump terminals, but it made no difference. I suspect it's internal smarts failed to detect what kind of load I had running and gave up.


    The dimmer seen above is the second one I got my hands on.


    I'd suggest trying to find a fixed type Leading Edge dimmer. Reading other posts on the topic suggest you want one with a rather low minimum wattage rating. Most vibration pumps are apparently in the order of 40W so you want a minimum well below this.


    Now, on to installing the dimmer into your machine.


    Disassembly


    You'll need only a philips head screwdriver for this part, it's a pretty straightforward machine to get into.


    Take out the water jug and drip tray (might as well clean them while you're at it).


    Most important: Unplug the machine from the power.


    Then start by removing the two screws on the lower back of the machine.
    Try not to get confused by the reflections in the panel - a stainless steel machine is hard to photo!





    Put these aside in a safe place, note they're ever so slightly different to the ones you'll pull off inside shortly.


    Now the 4 blobs on each side of the machine are also screws, covered with separate screw on caps. These caps can be removed without damage by covering them with a rag before gripping gently and turning anti-clockwise with pliers to loosen them. Then you can then unscrew them the rest of the way by hand.



    Under the caps are the screws to remove



    take all these all out and then both sides and back should basically fall off.



    Next remove the 4 screws near the top on both sides



    Take note of the screws as you pull them out, two are slightly shorter than the others. A good trick is to tape them next to / near the hole they came out of with some masking tape.


    Then with some lifting and jiggling the top frame and water jug should lift and fold back on the wires and pipes. I suggest you find a wall or something to lean it on to not stress the connections too much.






    Now looking down inside it you should find the main pump closest to the front of the unit, mine's red;



    The pump has two wires on standard spade connectors.
    We're going to put the dimmer inline with (either) one of these.



    Installing the dimmer


    You'll need a male and female spade connector, to be crimped onto the two dimmer wires.



    It would better to have ones with a shroud, I had these ones on hand so put some heatshink over them for insulation after I'd crimped them onto the dimmer.



    Next you'll need to unplug one of the wires from the pump. It should wiggle and pull back off the terminal, it's not clipped on as such but it is fairly difficult to get off the first time.


    Then plug the dimmer wires onto both the pump and the unplugged wire before tucking the dimmer out of the way to the side where the knob is accessible.



    Test it


    Now fold the top and back into position and put in a couple of screws half in to hold it in position.
    You can put the water tank back in now and power up the machine, as long as you promise yourself to keep your hands well out of the insides while it's plugged in. If you're unsure, keep one hand behind you back (or in a packet) the entire time the machine is running with the sides off, this will help you focus on the one hand you're using.


    Start with the dimmer on max and turn on the machine. Once it's warmed up try to start the water / pull a shot. Hopefully your pump runs and the machine works like normal.


    If you hear a click but no water, unfortunately your dimmer is probably not compatible. Double check it's turned up to max and try again. If there's still no joy, bad luck. Unplug the power to the machine and then and only then unplug the dimmer before plugging the machine's wire back directly into the pump. You could try re-wiring the dimmer the other way around, or try the other pump wire, but this didn't work for me. You may need to just try a different dimmer like I did.


    If it is working however, you can try turning the dimmer down slightly and see if the pump still works, then keep turning it down gradually to see what range you get. It's then up to you to play around pulling shots and and checking out the change in pressure as you use it.


    With my dimmer however, even on max it slows the pump down a lot. It sounds different, probably a bit louder too. The dimmer possibly also has a bit of a soft start in it, when the pump first clicks on I can hear it ramping up slower than normal. Either that or its just a function of the reduced power.


    With the leading edge sort of dimmer I believe it should be safe for the pump, if anything it should extend its life a bit. I'm not certain though and could be quite wrong, hopefully I don't burn out my pump and I definitely don't make any guarantees.


    The pour


    If I pack and tamp the coffee as per normal, I now get the pressure gauge showing 9 - 10 bar instead of 14 - 16.


    The first couple of shots I pulled tasted great, definitely a big improvement for me!


    Also, I can now use my naked portafilter without making a mess :-)
    No more spraying at all, I get a good consistent pour, looking very nice.


    Your milage will definitely vary though, each dimmer will likely behave differently. I tried turning the dimmer down a bit and the pump almost immediately stopped working altogether, so for now I don't have much adjustment, just the reduction mentioned above. I've already ordered a different Leading Edge dimmer to try, see if it behaves differently / better.


    Back in one piece and good to go
    Once you've tweaked the pressure a bit and are happy with the pour rates, re-assembly is just the reverse of disassembly.


    Fully screw the top back with it the 4 self tap screws on each side.


    Be careful putting the screws back in, they have a tendency to cross-thread / self-tap new threads. Best to try twisting them the wrong way by hand a little until you feel a slight click, this is the thread falling into place, then you should be able to tighten up again.


    Then sit the back on in place, the top lip fits into a slot below the top of the machine. While it's sitting there, the sides can go on and be screwed in, these hold the back in place.


    Finally the back bottom two screws. If they don't immediately go into the hole you may need a torch to check if the holes in the metal line up with the holes in the black plastic behind it - you may need to use a tiny screydriver or something to poke in and wiggle the black bit down / across to line up the holes.


    Enjoy the smoother coffee!
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