kempy

Coming to the shed tour? can easily show you what's (not) happening on this machine

Here's my attempt at MS Paint. *cough* The water you drink that's used to make an espresso isnt actually from the boiler, it comes from a cold feed that in supplied via the injector tube. It's mixed in a heat exchanger tube which is inside the boiler, the water from the heat exchanger sits at about 90-96 DegC normally, the boiler is around~120DegC ( differs to machine and setup) but its hot enough to produce 1 bar pressure and supplies the steam for foaming milk etc, so all the heavy elements tend to get left behind in the tank. The water inside the heat exchanger tube forms a natural convection current and flows through the group head (Solid shiny bit bit on the front of the machine that the coffee handle goes into to extract espresso) and as it cools it recirculates back through the underneath pipework and into the bottom of the heat exchanger, and repeat... My pet hate is when Barista's have only boiler water for Tea/Long Blacks etc, ( some machines have a separate supply just for this) as it can be pretty average water at times and is so hot it burns coffee/tea making it bitter. One of the real tricks is getting this thermal siphon speed right and keeping the group head temperature spot on. Something that's fairly uncommon and utilized on this machine is that it has Temperature bias/flow adjustments on each group head circuit, you can see both of them at the top of the boiler-> on the larger curved pipes (orange section) going into the back of the group head.

You have about a week left I reckon.

Don't worry, pretty sure its not contagious

Stripped down for cleaning Just stole the spray and wipe from the kitchen and will let it soak in for a day.

Back to the machine with the boiler out, light bit of corrosion, seen far worse in these machines. The pump isn't happy at all and it's broken free of it's rubber mounts, between the leaks and pump noise this thing must have sounded like a tractor.

Nice BMW spotting Pete! I think this was a 'Vegas machine, that area is pretty hard on them. It really depends where you live in Auckland and how well/often you change filters, but this would be many years in Auckland, 2-4 in' Vegas. The results can differ a lot in the same area of the city though, it almost seems like some of the low lying areas of the water supply are worse than others, as if the deposits as heavy and travel down hill and settle in the machines when compared to machines further up the hill as odd as that sounds. Wee bit more progress as I delve into the bowels of this machine. Enjoy!! View inside the boiler, you can see the water level mark on the L/H side This sludgy bit is the bottom, some of it was around 2-3cm thick Flushed out 60-70 % of the loose stuff

I haven't really pursued them because I have original Osram and GEC ones. I have a couple of Chinese ones here just for the purpose of bench testing.

I bet the owner was wondeing why it was so slow to heat up Might be in luck, most of the lime scale is in a muddy state, it hasn't set rock hard and most of it just washes off with a hose. Comparing the water from the boiler to last night's picture it shows that most of the lime scale is being carried in the water.

Lol, they're not usually this bad.

I was told the proviso was that you had to be a weirdo and that's how I got invited??

Might be easier to get some reissue KT66's as typically they're designed around a 6K6 OPT, KT88's around a 2K5 OPT.

Time to drain the boiler so I can pull it out and inspect, normally you'd do this in place but indications are that I'll need to strip a pile of crap out from inside. Here's better view of the water, I'll keep it for the shed tour and the one to drink it gets some beers.

Just general 450v electrolytic's and 630v foil caps for coupling/bypass. 2200uf is a Huge psu reservoir cap if you use a valve rectifier you'll fry it. most amp's are using 20-100uf caps with chokes or resistors in between. KT88's are even harder to get originals unless you go for new issue ones. Do you still have the original output tubes still and know what condition they're in? I have an AVO valve tester here you can test them on if you do.

The Boiler. First off, to decide whether this is going to be a salvageable machine we need to see what condition the machine is like internally, if it's heavily corroded inside the boiler and pipes then it's probably write off which I really hope it isn't, I'd really like to keep it, normally there is a degree of lime scale build up. Here's a look at the water heater leak wit the cover off, as said before it's had this leak for quite some time to get a scale build up this thick. Another issue is that one of the connectors has been loose 2 of the terminal have got abnormally hot it's started to break down the plastic cover on the red and black feeds.

Here's a close up of the group head, despite looking quite pitted, I think they'll come up ok with a polish and cleaned out internally. There's a few dents in the chrome but it's not worth the hassle getting it fixed. A peek inside the rear cover shows that the leak was spraying into the cover, it must have been hissing a fair bit! Now we start to get a bit of a clue what the machine is like internally, this water level should be white, the water inside looks like a bunch of pox.

Here's a pic or the rear, already with a quick glance problems present themselves. From here you can see a lot of lime scale facing the bottom panel indicating a long term water leak, there is black powdered rubber on the pump motor which indicates the pump has been shaking a fair bit for some reason, and the blue end of the boiler indicates that there is a major issue at the other end. Moving around the boiler it becomes pretty obvious that there has been a long term leak around the heating element with the amount of lime scale build up. Moving back around the front, the tray shows some signs of rust and corrosion on some of the pipes, the group heads also have a degree of pitting. Hopefully they'll clean up ok and the boilers is in reasonable condition.

Shed's all tidy and I'm still waiting for stuff to turn up for other projects so I can make some progress, so I might as well do something. This is a rebuild on one of 2 Faema E61 Legend's that are sitting in the shed slowly decomposing. I'm going to post lots of pics for a couple of reasons such as a bit of info for someone else wanting to fix their own machine or that whenever people take their coffee machine to the repairers, they feel like they've been ripped off, in some cases that may be true, generally these machines need a ton of work when they haven't had regular maintenance. I've chosen a machine that's typical of a couple of years of no servicing and bad practices when being used.(will explain later) edit: ok this one is fairly grotty now I've opened it up So here we have it, a reasonably common and well loved machine by Barista's all over the world, it's circa 2001 (not the original 1960's one that cost moonbeams to buy now), but still a well respected machine.

El37's are a really nice tube, I think they sound nicer than el34 or KT88 in a lot of applications. Why not stick to them? Also I can hook you up with HV caps nice and cheap if you need.

If you're going to use that chassis and transformers you'll need to consider what the original output tube was to match the OPT. Also you'll need a fairly grunty power transformer to run a pair of KT88's in stereo. kind of looks like it was a 6L6 or EL34 chassis. That's a very nice surround replacement!

Same here, I raided the neighbors inorganic and scored some carpet. Every shed should have cream carpet...wtf. It was a moment of weakness, but at least I can console myself for not taking the underlay as well. Makes an enormous difference at night though, doesn't feel like I'm inside a fridge quite so much.

I guess our world record attempt at the most ever people in a Ford Escort on a day trip around Auckland is in limbo then?

well done, gently gently My Mrs has been telling her friends, I normally hear during the conversation "old school?, but Dave's not that old?" Yep..

5000lm is that per tube?, could be a good replacement for the old 450w mercury vapor lamp in the shed. Although it is nice to work under on a cold night. Chris I think I have a spare PDL 56 series 32a Socket and matching plug if you need one, your welder would love it.

Sounds logical, Just being nosey, are you (or whoever) doing the tests onsite or do you send them off to a lab for testing? We used to use SGS, cant remember who it was before them, I think it was our own labs back in Australia.