Decent Espresso Machines (DE1) - Any thoughts?

[>decentespresso]

Making water heaters : the connectors

Before we can have our water heaters manufactured, we need to get the metal water adaptors made for us by another company. This is a custom connection that we're using in our espresso machine because "the whole industry" is moving to this type of connection, as it works great. However, it needs to be made out of metal, not plastic, in high heat situations.

1000 of these adaptors came in yesterday. While they look really pretty, we found that the inside diameter has been made to 7.1mm, and not the 7.3mm that we specified, and so the water tubes won't fit. We enlarged some by hand. Of course, the 20 samples they made for us previously didn't have this problem. Sigh.

We've talked to the factory, and for $320 we can send them back to China to be fixed, and then sent back to us. Once that's done, we can send them back to China to the heater company. So that's what we're doing.

[>decentespresso]

Making a knockbox : the challenges of bending metal

Our manufacturer is having difficulties making a mould to manufacture our knockbox. The way this sort of object is usually made is by creating a solid metal form, that is pushed into a sheet of metal at high pressure.

The problem they're encountering is that stretch marks, appearing as lines, are forming in the metal as it's being stretched into the form.

They've tried two mould approaches (metal and plastic below) but no luck yet.

It's quite interesting to see the real-world challenges that exist in making these physical objects. It's also interesting to me just how rough and raw the initial bent metal is, before it undergoes cleaning, polishing and coating to hopefully (eventually) become the object in the render below.

[MrJack]

Our manufacturer is having difficulties making a mould to manufacture our knockbox. The way this sort of object is usually made is by creating a solid metal form, that is pushed into a sheet of metal at high pressure.

The problem they're encountering is that stretch marks, appearing as lines, are forming in the metal as it's being stretched into the form.

They've tried two mould approaches (metal and plastic below) but no luck yet.

It's quite interesting to see the real-world challenges that exist in making these physical objects. It's also interesting to me just how rough and raw the initial bent metal is, before it undergoes cleaning, polishing and coating to hopefully (eventually) become the object in the render below.


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John, have you looked into metal spinning? Looks like a design which *might* be "spinnable" (though it may need some machining to complete). Relatively low prototype cost too.

Edit: Actually, looking at the photos more closely I see it isn't rotationally symmetrical (which is required for spinning).

[>decentespresso]

Ceramics parts finally looking good

I reported a few weeks ago that we had to fire, very late in the process, the ceramics company we've been working with.

We then upgraded to a much more expensive company to make our ceramics ($9 and $13 to make these parts, instead of $1.50 and $3) but they're working quickly, and more importantly, their work is super-super-super high quality. They're using a compression mould technique instead of slip casting, and a very dense, fine clay. They recorded this video yesterday for us from their factory, where they're testing fit using the espresso machine legs we made for them.

I'm looking forward to seeing the samples in person.

[>decentespresso]

Testing tablets

1000 tablets have been made for us, but I'm very, very wary of the quality control process with high technology products. Most Android tablets I've evaluated from myriad companies have had issues. The one I decided on was perfect (no hardware problems, clean and functioning Android install)

However: in Bordeaux, France, I ran into someone who used to buy tablets from this same company (when he worked for Argos, a huge UK retailer), and he said that they had a 15% quality-control failure rate but were otherwise a very good choice.

So, I'm not taking delivery of any of these until every single one has been powered up and checked to be perfect.

I was in London a few weeks ago and bought this tablet from Argos' retail store to see what they were selling, and I found an air bubble on the screen of mine. I also found that Argos had "upgraded" to their software include annoying "trialware" of things like Angry Birds. Our tablet uses a clean Android OS installation that has Google's apps, and nothing else.

[>decentespresso]

John, have you looked into metal spinning? Looks like a design which *might* be "spinnable" (though it may need some machining to complete). Relatively low prototype cost too.

Edit: Actually, looking at the photos more closely I see it isn't rotationally symmetrical (which is required for spinning).

As you noticed, we can't spin it, but I have asked the engineer to try using 304 stainless steel instead of aluminium, to see if that metal doesn't have the same stretching problem. A different metal thickness might help as well.

[>decentespresso]

VIDEO: Introduction to flow profiling

I've made a video explaining how flow profiling works, how you configure it, and you can see a shot being made with this new approach.

[gc]

I've made a video explaining how flow profiling works, how you configure it, and you can see a shot being made with this new approach.

I am so looking forward to doing this in my own kitchen with a DE1+ ordered. First time I've actually seen it working in full, including the software in action. I had been a bit worried about complexity of profiling, but it looks easier than I thought.

[simonsk8r]

Wow, haven't read through the whole thread, but have looked up the site and watched the flow profiling video.. utterly utterly fascinating.. Not sure if I'll go down that route but awesome work being done hey, very cool!

[level3ninja]

I'm really excited about what you're doing John. I love that you're trying to make the best espresso, regardless of how that occurs. Your machine isn't very traditional, but I have a feeling that in 10 years or so people will point back to your machine as one of the major stepping stones in the progression of espresso technology and understanding. I was pretty sceptical at first, as I expect most people were, but the more I see the more I think my next machine will be one of yours. I wish you every success.

[Crema_Lad]

Wow the flow profiling, as does your machine looks amazing! Been following along and love the integration of technology and combined coffee guru knowledge that's gone into it. Certainly might be on my upgrade radar in the future! Be quite an upgrade too from my wee Breville 920

[>decentespresso]

Thanks everyone, you're all very kind!

[>decentespresso]

Easy to replace PC Boards

I've mentioned before that we make our own PC Boards -- from scratch. I know this sounds insane, but it allows us to make revisions to our boards and improve them every few weeks, rather than doing larges batches. Outsourced PC Board companies don't like making just a few boards, because there is so much parts set up time involved. On the DE1 we have a "high voltage" board to control pumps and heaters, and a "low voltage" board that is essentially a computer, talking to the sensors and to the high voltage board.

In building our recent "release prototype" we found that if a PC board were to fail, that you would need to take apart most of the inside guts of the DE1 to replace it. Whoops.

The reason for that difficulty is that we were screwing the board down from the inside at the beginning of DE1 assembly, and later, when all the pumps, heaters and such are in place, you can't get at those screws any more with a screwdriver. All the stuff inside is now in the way.

Today's revision fixes that problem.

Small "bolts" are now soldered to the PC Board directly, so that the screws now slide from the back panel of the DE1 (from the outside), and tightened using a screwdriver with the whole machine staying assembled. It also means you won't have an "oh shit" moment when a screw falls inside the machine and you can't find it afterwards.

[>decentespresso]

Making connections stick

Back in November, when I first toured with the DE1+, my prototype machine broke down often because wired connections would come loose from the espresso machine being thrown around so much during traveling.

We've improved that quite a bit since then, but even now, on this tour, I had one wire, on one valve, that has kept coming off. Each time I traveled someplace new, before a demo I would pop off the top of my espresso machine, check the wire, and (usually) put it back into place with a pair of tweezers. Not cool.

To fix this problem, we're doing two things:
1) wherever possible we've replaced wired connections with small PC boards that fit over the connectors, and the whole thing is soldered in place
2) locking connectors everywhere else.

For our mixing chamber, which is a very parts-dense area of the machine, we designed an L shaped PC Board that fits over all the valve connectors, and which also brings 5 temperature and pressure sensors into once place, with a locking connector sending the data back to the low voltage PC Board.

This board just got manufactured (by us) today and we'll be putting it in place on monday.

For a humorous comparison to where we've come from, I've included a photo of the last "R&D prototype" we made, before redesigning everything for proper manufacturing.

[Lav]

For a humorous comparison to where we've come from, I've included a photo of the last "R&D prototype" we made, before redesigning everything for proper manufacturing.

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Ha ha, this is how all my machines looks - after me tweaking...
I wander when I will void your guarantee after receiving the DE1+ this fall [emoji4]
But until now you pretty much implemented all those features I could think and dream of