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PostPosted: Wed Nov 08, 2006 1:19 pm
by ben_edwards
I think what you are trying to achieve can be done really simply, but I don't know how effective it is, as the water needs to be mixing a great deal as it goes into the boiler. Anyway, simply pull a heating flush for a few seconds, lock in the pf, hit the steam switch for a couple of seconds and then pull the shot. This would leave you with an extra hot boiler for the fresh cold water to hit as it rushes in from the reservoir.

PostPosted: Wed Nov 08, 2006 10:53 pm
by lukas
Ben, but would this not also give you extra hot water to start the shot with?

PostPosted: Wed Nov 08, 2006 11:57 pm
by Aadje
slightly off topic: Lukas, what grinder do you got with your gaggia?

PostPosted: Thu Nov 09, 2006 12:04 am
by lukas
I have a Gaggia MDF, slightly modded - I removed the springs that are responsible for holding the grind setting. So I have to hold the beancontainer while grinding, but now have a steppless grinder: )

PostPosted: Thu Nov 09, 2006 12:20 am
by Aadje
let's see if my grinder will allow me to remove those or alikes. Thanks

PostPosted: Thu Nov 09, 2006 12:52 pm
by ben_edwards
Ben, but would this not also give you extra hot water to start the shot with?

Well I'm thinking that there is some sort of lag between heating the boiler walls and heating the water within the boiler for this burst of heat. So if you make it a short flick of the steam switch then instantly flick the brew switch I think the first water out will be normal boiler temp - loss due to group etc., then the later water will have a little extra heating to get it up to temperature quicker. Its just a guess...

I like the idea of modding my mdf grinder but its under warranty, I was thinking of adding a circle of something flat and thin to get rid of the grooves, or even better make lots of little grooves so its still stepped but say twice an many steps. Having said that I usually get by with what I have and vary the tamping and it sounds like something beyond my capabilities (i.e., beyond a bodge) so I'll probably leave it!

Aadje, I've noticed that the solis grinders (well actually the dualit ones but they are the same aren't they?? so you could just say it was a dualit ;) ) seem to hold their value very well for resale on ebay (they go for £30+) this seems bonkers as I'm sure the burrs are not meant to last too long and are non-replaceable. Its probably a brand name thing. Anyway you might want to offload that grinder and get something chunkier? Having said tha tt he situation may be a little different in the Netherlands.

PostPosted: Wed Nov 22, 2006 2:53 pm
by lukas
Ben, I think I have achieved something similar like you describe. It doesn't work on a Classic, though, because it has a 3-way-valve, my Coffee Gaggia has not.

To overcome during-shot temperature variances, I just have to switch the steam switch a few seconds into the shot for a few seconds every few seconds (to get this to work on the classic, you'd have to somehow bypass the PID and trigger the SSR manually. Steam switch won't work beacause it also cuts the water flow to the grouphead).
Which would be the same as installing a 2nd PID with different parameters for intra-shot temperature control. With a bit of practice, the reading on the PID stays between 106 and 108°C during the shot, with an overshoot up to 114°c after stopping the flow.

Verey noticable differnence in the taste!

PostPosted: Wed Nov 22, 2006 2:59 pm
by bruceb
It seems to me that if this is what it takes to make a good shot it's not surprising that many folks go to inst*nt! :shock: :?

PostPosted: Wed Nov 22, 2006 3:25 pm
by lukas
Or buy commercial machines, like you Bruce!

PostPosted: Wed Nov 22, 2006 3:44 pm
by bruceb
Ohhh, uhhhh, ohhhh well, that's uhhhh different :oops: :oops:

Re: Gaggia Classic, Schematic diagrams, PID-ing

PostPosted: Tue Sep 03, 2019 2:39 pm
by Abie 2
Hey there!

I would like to seek your advice. I would like to drink good coffee every morning so I decided to purchase an espresso machine. I can't decide between Rancilio Silvia and Gaggia Classis though. I found an article with pros and cons but I'm not sure yet. Can you please help me? Thank you!

Re: Gaggia Classic, Schematic diagrams, PID-ing

PostPosted: Sun Sep 29, 2019 10:33 pm
by CakeBoy
Hello Abie2 and welcome to TMC. My apologies for you waiting so long for a reply.

In short both are good machines in their class and you might be best to see what price each is available for in order to get the best value.

Be aware that you will have to ‘temperature surf’ in both as they are single boiler machines. That means you will need to flush in order to reach the desired brew temperature and go between brew and the much higher steam temperatures. Achieving intra-shot temperature stability, that is during the pour, is also something you would need to practice as well.

Have you any experience of either machine or espresso making at all? I would recommend you might also consider a dual boiler or HX machine, maybe second hand, if your budget allows and they are available at a reasonable price where you live.

Whatever you choose, a decent grinder is imperative, it’s far more important than the espresso machine. Have you got a grinder or have you one in mind?