Decent Espresso Machines (DE1) - Any thoughts?

[matth3wh]

Looks like some great feedback and design updates/tweaks there! Ceramic heating looks like a good win. Hope that's works out well. Improved energy efficiency and warm up time are excellent improvements.

Nice touches on the tablet USB charger/mounting too!

DE team kicking goals.

[TampIt]

- design thinking into what a stamped metal group head cover should look like. (industrial design, Joao)

From a designer's standpoint, I've never been happy about having a big blob of simulated-metallic-finish plastic on the group head, right where everyone can see it, especially since we spent so much time and money using metal and wood everywhere else, to produce a high end machine.

G'day John

All looking good - well done so far.

FWIW, I reckon you should retain something close to the current shape as no other coffee machine looks similar. Always a good thing to look different as long as it is still esthetic (and that basic cylindrical shape is).

TampIt

[gc]

G'day John

All looking good - well done so far.

FWIW, I reckon you should retain something close to the current shape as no other coffee machine looks similar. Always a good thing to look different as long as it is still aesthetic (and that basic cylindrical shape is).

TampIt

+1 to the above comment.

[>decentespresso]

G'day John All looking good - well done so far. FWIW, I reckon you should retain something close to the current shape as no other coffee machine looks similar. Always a good thing to look different as long as it is still esthetic (and that basic cylindrical shape is).TampIt

Agreed on the cylindrical shape, but a quick googling for "espresso group head cover" finds a few companies doing aesthetically nice things with this part, so I think there's room for improvement with ours.

[>decentespresso]

Designing a group head cover

For the past two years, we've had a moulded plastic cover on our group head. It's been made in plastic to keep you from burning yourself if you touched it. We've recently figured out how to keep the heat in, so we can use metal to make the cover, which will be classier looking and more durable. We're thinking about using stainless steel, though we haven't decided between brushed (resists fingerprints) or shiny (very classic).

So, we're taking the opportunity to rethink this design, and below you'll find some initial concept sketches for ideas we have.

Which one do you like?

[>decentespresso]

Weight shots -- just came up with a much better idea

File this under the WHY JOHN SPENDS SO MUCH TIME ON INTERNET FORUMS category, I had a "holy cow" moment this morning where I put a 3D mockup of our upcoming Decent Scale under the drip tray, rather than on top of it. This was a suggestion made last week on HB (apologies, I forget who came up with it), and I realized that this is so much more logical than putting the scale on top of the drip tray cover.

With the scale on top, you lose a lot of espresso cup height, and you also have to worry about water getting into the scale, and it's another thing to clean up. A usb micro charger cable isn't really possible in this configuration.

Under the drip tray, it's out of the way, you don't lose any cup height, and there is no cleanup to worry about. Plus, you can plug the usb power into the scale in a way that isn't even visible.

And, totally by accident, my design of putting the LEDs and buttons vertically, makes this idea possible. This wouldn't work with most other scales, since they all face upwards.

To see if this would work, I put the maximum amount of water into the drip tray, I picked the heaviest mug (IKEA) I have and i put 100ml of water (a lungo espresso shot). Good news: we're still 200g short of the 2000g capacity of our scale, so this should work.

I'll need to make sure that our scale has enough clearance that it doesn't touch the espresso machine when it's on the scale, but otherwise this idea should be straightforward. Since we haven't finalized the ceramic drip tray mould, now is the time to nail this idea down.

On the DE1+ I can make the tablet software tare the scale automatically when you tell it to start making an espresso, and then "gravimetric" automatic shot-off becomes really easy to code.

[Melbroaster]

Thats awesome

[>decentespresso]

Thats awesome

Thanks! We're making good progress on the timeline for finishing our upcoming Decent Scale https://decentespresso.com/scale

The firmware is done, and we're testing different types of translucent plastics to let the weight LEDs shine through but have it all look like a solid black black front when it's powered off.

The top LED gives the weight, while the bottom LED stays off by default, and becomes a timer if you tap the [] button to start it.

[level3ninja]

I like design #2

[Melbroaster]

Question: With the weight of the driptray water, drip tray and mug on the scale (ie 1.5kg- would you expect that the accuracy of the scale to reflect each extra gram added to the scale to be as consistent as each gram added to the scale starting from a zero load?

[thebookfreak58]

Why not embed the scale in drip try a la https://home.lamarzoccousa.com/wp-co...o__AWA0015.png

[>decentespresso]

New: lighter drip tray, flush diffuser, new mixing chambers

Lots of interesting espresso-parts stuff arrived today (saturday), and so I thought I'd share...

Yes, the pace of postings is picking up from me, because we're wrapping up so many different things up and can proceed to making these machines. It's mostly mechanical stuff at this point: the tablet software and firmware is looking good, another month or so of work to do.
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DRIP TRAY

We're looking at alternatives to ceramic for the drip tray because:
- it weighs 770g (1.7lbs) -- that's really heavy to air ship these to you.
- it can break if you drop it
- it is not easy to add plumbing to a ceramic dish
- if we want to add "gravimetric" dosing by putting the scale under the drip tray, saving 500g will really help us get way under our 2000g scale limit.

We're considering melamine for the drip tray (NOT for the water tank, have no fear), and today we received samples of a metaline container that is very similar in dimensions to our ceramic drip tray, but it comes in at 1/3rd the weight, and won't break (easily) if you drop it. Plus, you can mould a plumbing drain in it fairly easily (for the DE1PRO).




Melamine FAQ:
https://www.fda.gov/Food/ResourcesFo.../ucm199525.htm

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We're still working on a "flush diffuser" (what slows down a flush so you don't get splashed) and we've decided that the best solution is to have a big enough container to hold the "waste water" and then let it splash around and drain out. We prototyped the idea below yesterday and it worked well. In order to weigh the drip tray, we need to have a few millimeters of "play" around it, so that the drip tray doesn't touch anything, so we think that moving the diffuser into the machine body itself, and not close to the drip tray, is a good idea.



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Our new iterations of the manifolds (mixing chambers) came in today, made from high-tech Ultem. The big improvement here is that the water connectors are now all moulded directly into the Ultem, and everything is using "clips" to be held into place. This removes a lot of material needed (lower cost), removes lots of potential water leak sources (every water seal is a liability) and greatly simplifies assembly *and* repair.

We also received a new iteration of temperature probes (with the threads, in the photo below) but we're hoping to move off of those, and have a "clip connector" design for our temperature probe, because threaded components that have a water seal on them are notorious to get right in production: if you screw them in too tightly you stress the seal out, and too loose and obviously you leak. The clip connectors don't have that problem. The parts for the new "clip connector" temperature probe design is in that upper plastic bag.

We're also trialing a new kind of gold-tipped temperature sensor in the small manifold -- keen eyes will spot 3 little drill holes on the amber-colored component on the right. We'll decide in the next two weeks on which of these 3 temperature sensor options we want to go with.

[>decentespresso]

Why not embed the scale in drip try a la https://home.lamarzoccousa.com/wp-co...o__AWA0015.png

Because:
a) that design is a mess to clean up. Lots of crevasses for espresso to drip into and dry
b) you can't get a usb cable in there to keep the scale charged
c) you can only weigh a single cup. Double-spout portafilters won't work.

[>decentespresso]

Question: With the weight of the driptray water, drip tray and mug on the scale (ie 1.5kg- would you expect that the accuracy of the scale to reflect each extra gram added to the scale to be as consistent as each gram added to the scale starting from a zero load?

You are absolutely right to point this out.

Generally, with a load sensor, the more weight you put on it, the less accurate it is.

With 1 kilo of ceramic and a full drip tray of water on it, our shot weighing would be accurate to 1g. That's still pretty good, considering that when you stop a shot, there are still a few grams that continue to come out, so that accuracy in weighing espresso shots isn't usually needed to be more than gram accurate. And what I'm describing is the worst case scenario (full drip tray of water, ceramic material)

That's one reason why we're working on lowering the weight of the drip tray from 770g to 250g, by moving away from ceramic and having a melamine drip tray.

Assuming your drip tray is mostly empty of water, a melamine drip tray should give us espresso-shot-weighing accuracy in the 0.3g to 0.5g range, probably more than is needed for this application.

[>decentespresso]

When will the decent espresso machine ship?

I get asked "when are you planning on shipping this machine" as well as "I thought this machine was done? why are you still fiddling?".

Those are very reasonable questions , and here's what I've got to say on this topic.

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THE SALES TOUR:

Back in November, we had a working Beta machine. Not yet feature complete, but close, and making good espresso. I went on a two month sales tour, and received a lot more interest than I had expected, especially for the DE1+'s high end features. People wanted to place orders right now, give us money, to get in line to get one of the first machines. I thought we were just a few months from being able to make what I was demoing to the public.

During the tour, my 3 Beta machines broke down several times due to shipping damage. Upon my return to Decent HQ in January, I decided to fire my mechanical engineer due to these problems, and a lack of progress while I had been gone. I hired a new one to redesign how everything was mounted inside the machine. As we went through all the internals, component by component, we found lots of areas that were "ok", but really could be improved, and rather than wait for a future version, I decided to do the improvements now.

These improvements meant:

- easier to repair (with more space inside, comes apart easily)
- longer machine life (with better cooling, many fewer water seals, longer parts longevity)
- lower energy consumption, faster startup
- better espresso (better temperature stability, better pumps)

Since it's Bugs and I funding this company and the R&D, I felt it was our decision to make: to spend more time and money making the DE1 machines better for even the earliest customers.

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SOME POTENTIAL FUTURE PROBLEMS FOUND

In February I hired Jeremey and Matt from Blossom Coffee - two founders of a company who did something similar to us five years ago, but it didn't go that well. They're serious engineers and businessmen with direct experience in our field, and:

a) their extensive review of our hardware uncovered new problems with our existing designs, especially in terms of longevity

b) they had many performance improving suggestions that I thought were worth doing, and that I'd feel bad if our 1st customers didn't have.

The big component I was avoiding touching was the heated group head, because it worked, but Jeremy's arguments for longevity and better & faster temperature control won me over, so I decided two weeks ago to bite the bullet and implement his suggestions.

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DESIGN FREEZE END OF APRIL, MANUFACTURING START IN JUNE

We're making great espresso, just as we did back in November, and we're whittling down the list of mechanical decisions.

Our deadline for hardware changes is the end of April, at which point the CAD model moves away from my "creative" mechanical engineer, over to my two "production" engineers, who will refine the drawings for each manufacturing partner, so that each gets made, and we'll start ordering final parts in May. Manufacturing of these "early access" machines then starts in June, and that's when we'll also be applying for final UL certification.

And of course, the day-to-day discussion progress will continue to take place on this forum and on HomeBarista http://www.home-barista.com/marketpl...43925-730.html

- John Buckman, co-founder.