A few months ago, I published and Instructable titled:
“Pocket size Espresso Machine with integrated alcohol stove.”

I got a ton of comments on the design; a good number of them focused on my use of copper as the main build material.
Questions of material safety with food were raised and some people even went the extra mile to see if using copper in this way was food safe.

A second point was also raised, that it was not really an espresso maker but a moka pot, due to its inability to exert sufficient water pressure on the coffee grounds.

So, for all of you, I went back to the drawing board and came up with a new design that solved both the copper and the pressure problems!

And incredibly, it's also cheaper and easier to make!

BTW, it is just big enough to hold 2oz of water so you can pull a double shot :D

A short video of the machine in action:

Step 1: Design constraints

The espresso maker works by releasing air at high pressure into the brew chamber (I used a small bike pump to build up the air pressure).

It works just like the commercial Handpresso which is my main inspiration.

To build this, I set the following constraints:

  1. All water handling parts had to be either aluminum or stainless steel.
  2. All parts had to be easily and cheaply obtained.
  3. Only simple tools could be used.
  4. It must be safe (no exploding parts due to high pressure or hands burned by hot water)
  5. Must be easy to give maintenance (sometimes overlooked)
<p>The concept is good but the parts been used might not be health friendly. The glue, the plastics and other things too might harm at high temperatures. I've seen many brewers come under $50 under the Hamilton brand, I've seen them here <a href="http://www.friedcoffee.com/11-best-drip-coffee-makers-for-2016/ " rel="nofollow">http://www.friedcoffee.com/11-best-drip-coffee-makers-for-2016/ </a>and I don't think affording $50 would be a problem for any.</p>
<p>It would be awesome to somehow integrate a hand pump into the design. This would be killer among the camping/survival community. Thanks for another great Instructable.</p>
<p>PVC with hot water can harm your health. But this is a great idea!</p>
<p>That's why the hot water never touches the PCV :D It's only the compressed air thats in contact with the plastic </p>
the materials that are used in the wallmart tire valve maybe made in china. most like it has lead in the brass. and the plastic may also. there maybe other not so friendly chemicals involved also. be careful with any items from china.
The PVC is US made. As to the valves, the contact area es really small ant they are only in contact with hot water for a few seconds. But, to be safe...Is there any way to test the brass for lead content?
use a test stick you can buy. or find a lead inspector who might test it. it might cost you but you would know for sure.
Thanks, I'll do that
<p>I just came across this and I think it is intriguing, although I'm not sure I understand how everything works.</p><p>In regards to the brass, it is probably free machining brass (C36000) which contains 2-4% Lead. If you live in California, they now has some restrictions on lead content (although it may not apply to bicycle valves, since they aren't designed for the food industry!). </p><p>Anyway, I was hoping you could upload a schematic. I was working on something similar, and I am hoping to steal ideas from your design and incorporate a pressure gauge, and if possible have an automatic pressure release (so you can't blow it up).</p>
<p>I just noticed the schematic. I guess I must have scrolled down before the image loaded. Sorry about that!</p>
<p>Hehe, no problems. Did you figure it out? </p>
<p>I think so. It looks like it is essentially 3 chambers. The bottom holds the coffee grounds in the filter, above which is the water pot which has an inlet valve (actuated by the bolt on the outer body) and the top most chamber is an air chamber that pressurizes the air (via the outermost inlet valve). Correct me if I am wrong.</p>
<p>You are right. You could simplify the design by eliminating the &quot;explosive valve&quot; from the outside. The idea was to release all the pressure at the same time, but in hindsight, the variations in pressure by directly coupling the bike pump to the machine will not be significante, especially if your using a &quot;cream enhancing&quot; portafilter. This way, you eliminate the valve that touches the hot water, and any risk of lead in the brass leaching out. Or you could change the valve for a espesso machine emergency and make the shot go off &quot;automatically&quot;</p>
<p>hi,</p><p>what is the external valve ? ( on the right on ur first pics) what is its usefulness?</p>
It's the air inlet valve: It allows you to pump air into the espresso maker
But there are two valves, one to release and another one to pump air into the espresso maker?
<p>That's right. You need the two valves in order to build up pressure. The Air inlet valve allows the pressure inside to build up, and the second one allows that pressure to be instantly released to the hot water.</p>
Awesome work, already started collecting the parts! My filter fit perfectly in the the same size union you used :D A question I had, were both of the tire valves stripped down to the brass or is is the air filler valve stock with rubber? If it is stripped, how does it stay in the cap under pressure when silicon or PVC glue isn't adequate?
Hi! <br>Yes, the valves are the normal stock rubber ones that i striped down. The way I got them to work was that the hole I drilled for them was just a tad small, so i had to pressure fit them in. <br>
I can see how that works but seems a little dangerous for the outside valve. Why not leave the rubber bulb on and install it how it was designed by drilling a 1/2&quot; hole and popping it into place? Is the bulb too big to fit in the air chamber between the two caps? Progress is being made, just wish I had access to a lathe to thin down these pvc parts...
That's a GREAT idea! <br>since it's rubber you want to thin down, you could place the valve with the plastic top on into a drill and use it as a mini lathe.<br>Please tell me how your build goes
That is amazing. I am going to start looking for parts tonight. <br>It would be great if it had a pressure gauge on it so you knew when you pumped up to 16bar.
Hi wakefield!<br><br>Look for a portable bike pump with integrated pressure gauge :D<br><br>If you can, share pics of you build!
I will look for one with a pressure gauge built in. <br>I know the air valve is spring loaded, but is there any added value in making the screw in the air release spring loaded? <br> <br>Do you have any suggestions on places to get syringe plunger heads?
Well, I don't think there's any added value, but I can be wrong.<br><br>As to the plunger heads, any Walgreans or Wallmart will sell syringes.
Somebody is likely to give you grief over the use of aluminum. And all stainless steels are not created equal. PVC is also likely not food grade.<br><br>Me? I don't care. The caffeine may be similarly unhealthy, especially at espresso doses. Perhaps you could call it the Coffee Crackpipe?
theres a pretty good rant on youtube about the merits of caffeine.. i lol'd and went and had a cup o joe. <br> <br>http://www.youtube.com/watch?v=OTVE5iPMKLg
Well, all that grief made me come up with this design, so please, let it begin (mabe a 3 version will be on it's way)
if you could market a design like this, you could be a millionaire in no time =)
My wife would love that :D
i'd bet so<br>i would love to buy one too, maybe even 2 since i would use it so much it would probably wear out haha
Fantastic build.<br /> Any updates after using it for a few months? Any thoughts on improvements?
Hi Senorsecroft, <br> <br>Well, actually I'm working on version 3 of my espresso maker. This will be (hopefully) a lever machine that put out some really high quality espresso. <br> <br>On the other end of the espresso tool chain, I'm halfway done with a new kind of grinder.....let's see how that turns out
Sounds fantastic. Any sketches that you could post as a teaser? Are you thinking of a lever system similar to some of the water filters? I'm looking forward to seeing the result. Thanks.
HI!<br><br>I&acute;m actually trying to make a la pavoni type machine. The hard part is trying to &quot;out design&quot; the need for any type of metal manufacturing, so that anyone could built it. The PID boiler is also a real challenge, but I've come up with a new/old idea that will make it workable.
Quick question, Could I use hot glue instead of pvc cement
You know, I used Hot glue on my first attempt. It leaked air like crazy. It seams that hot glue and PVC don't bond strongly. <br>So, I had to use the PVC Cement.
I can't believe you would go and update your design while I was in the middle of building your pocket model. Now I have another project to add to the heap.
Just take comfort in it being well-designed!
Great stuff! I just bought the pieces, but couldn't find the same diameters as you. Since I have to adapt my design, I have a few questions:<br><br>1) how do you pour water into the espresso maker, and then screw in the coffee cup, without spilling one, into the other?<br>2) what's the glue you are using? Isn't PVC glue toxic?<br>3) what's the pouring hole look like at the bottom?<br>4) can you make another video with more detail, maybe showing how one piece fits into another, and the entire process of making coffee (no skipping the water pouting step ;)<br><br>Again, an amazing instructable, thank you for posting<br>
Hi gcc_mtl!<br><br>I'll answer your questions in the same order.<br>1) Since I tamperd the coffee hard, I turn the basket + Union outer ring upside down without the coffee falling out :D<br><br>2)It is PVC glue, but since it never touches the water or the coffee it's not a problem.<br><br>3) I didn't understand this question, can you rephrase it?<br><br>4) Yes, I just have to wait till my wife gets back form a work trip, since I need an extra pair of hands.<br><br>When you done, tell me how good your espresso is :D
Quite ingenituitive I must say.... good job.
aluminum and copper are mainly used for alkaline based food stuffs, acidic &quot;food&quot; like tomatos, coffee, spinach, and lemon corrode the metals. stainless steel is the one you want to be using..then of course you have the NSF breathing down your back...effing amazing though..you are more than in the right direction...cheers
to buy the parts find made in America . items from Canada might be from china and relabeled to be from Canada. go to a true value,ace, or other professional stores who would know if there is lead mixed in. there are stainless air valves out there for to buy. this idea does merit a look. :)
I like what I see. &amp; am interested enough to try to make one or mod yours.<br>But I was wondering if you had made or could make a Diagram of your Hand held Espresso maker. Your photos are great but it's still hard to see the whole concept.<br><br>Thanks for making cool stuff.
Done :D
Cool Thanks!
I'll try to make one today and post it
Great design.. i would love to see a video of it working... about the whole PVC thing.. i had similar comments about my coffee straw filter... i guess can't make everyone happy.. the time the liquids have contact with the liquids is very short.. so the chemical leeching is very limited.. great design
forgot to mention youtube is blocked for me.. but ill check it when i get home

About This Instructable




Bio: A tinker since the cradle, I love looking at things and trying to figure out how they work and the best way to mod them
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