Ever found yourself miles from anywhere, with no source of electricity, no possibility of making a fire, no means of rapid transport, and very much in need of a small, weapons-grade espresso? Well, no, probably not. But if you did...

MaxCo. is whelmingly proud to present its Machine for Coffee.

Unlike other so-called "coffee machines" - which involve electricity, fire, or pre-boiled water - the MaxCo. Machine for Coffee requires none of these things.

In its closed-and-holstered configuration, the Machine for Coffee vaguely resembles a pair of bolt-cutters, with a pair of long heavily-chromed handles lying side-by-side, attached to what can only be called the business-end of the machine.

The business end contains a water reservoir, a perforated metal container for ground coffee, and some other clever bits.

To operate, simply open out the two handles to their widest angle (about 60 degrees). You will notice considerable resistance, because the handles are cunningly geared to two sets of intermeshing closely-spaced discs in the water reservoir. Now close the handles again, as forcefully as possible. Open, close, open, close...constantly spinning the discs to and fro.

Where is all that effort going? Well, obviously it is going into the water which, degree by degree, gets heated up to and beyond 100°C.

Eventually, the small red button on the side of the head will pop up. This is the pressure indicator, telling you that the water has reached the perfect point of superheatedness. At this point, it is quite important that you stop pumping.

Now turn the heavy Bakelite knob on the other side of the head, releasing the superheated water into the coffee holder, whilst holding the nozzle over your cup. Gadulka! A perfectly perfect cup of espresso.
-- MaxwellBuchanan, Feb 05 2015

Tangentially related link https://what-if.xkcd.com/71/
Can you boil a cup of tea by stirring it? [hippo, Feb 05 2015]

Could it make.... calorie-neutral coffee?? Calorie-neutral_20Confection
Also relevant: Joule's kettle [mitxela, Feb 05 2015]

I particularly like the bit that says://Eventually, the small red button on the side of your head will pop up.// I have often wondered why I have that small red button on the side of my head and what makes it operate. Most enlightening.
-- xenzag, Feb 05 2015


Well, now you know.
-- MaxwellBuchanan, Feb 05 2015


An alternative design of coffee machine to this, also designed around the notion of converting kinetic energy to heat energy, could be imagined for those who prefer their coffee shaken, not stirred.
-- hippo, Feb 05 2015


33,500 J to get 100ml of water from 20-100C, say you want to do it in 2 mins, with about 20% losses. 335 Watts. Now, humans can do that. Not with your arms though. So you'd need an exercise bike type set up.

There's a wonderful line in Red Dwarf: "it's just not possible to fry an egg using a bicycle powered hairdryer". Sort of prior art...
-- bs0u0155, Feb 05 2015


In you plan ahead and spend 2 hours doing it, you only need 6 Watts (neglecting losses*).

* 2 days if you want to account for losses
-- the porpoise, Feb 05 2015


[-] for lack of ill-considered and highly inadvisable use of pyrotechnics and/or exothermic chemical reactions. i.e far too safe and therefore boring.
-- 8th of 7, Feb 05 2015


One wonders if the Borg ever get tired of exploding memes. Or even exploding mimes. Or memes about mimes on mines...
-- RayfordSteele, Feb 05 2015


//say you want to do it in 2 mins, with about 20% losses. 335 Watts. Now, humans can do that. Not with your arms though.//

Two points.

(a) 100ml of weapons-grade espresso is probably more than you'd want to handle, at least without training. We used to brew coffee in the lab, and the apparatus only made enough for about 30ml each. We made it strong enough to be dangerous in those quantities. With some clever fluidics, I think we can get the dead volume down to 10ml, meaning 40ml in total.

(b) My domestic espresso maker takes about 8 minutes to make a cup (although she is getting older and slower). I could compromise and go for 5min.

So, 40% of the volume in 2.5x the time, meaning that you only need a power output of 54 Watts.

Now, can we manage this, arm-wise? Well, let's assume that the travel of the arms (of the machine) is 60cm (ie, each arm moves back and forth by 30cm), and that each push and each pull takes 1 second (ie, total travel 0.6m/s). Energy=force x distance, and hence power = force x speed. Hence force = power/speed = 54/0.6 = 90N. Thencefore, you'll be pushing and pulling against a resistance of about 9kg, or 20lb if you live in the US. I think I could manage that.

//pyrotechnics// Perhaps we could interest the Borg in our MarkII machine? It is identical to the MarkI, but the delivery man pops a grenade through your letterbox when he delivers it.
-- MaxwellBuchanan, Feb 05 2015



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