Decent Espresso Machines (DE1) - Any thoughts?

[>decentespresso]

Bluetooth milk thermometer?

I'm ordering a new batch of our digital milk thermometers https://decentespresso.com/milk_thermometer as we're down to 100 Celsius thermometers in stock. This new batch will have a water proof coating on the thermometer PCB, for improved water resistance.

When talking to Mingle (our thermometer manufacturer https://www.mingle-instrument.de/digital/) I also brought up the topic of adding bluetooth to it.

They said that they can't add bluetooth to the existing thermometer, as there's not enough space.

But they propose this two-part bluetooth thermometer (photo attached) to me, which they made in 2015 for another company:
At Google London a few years back, I saw that their La Marzocco Espresso Machine had a probe like this clipped permanently on the steam wand. In their case it was simply going to a digital thermometer readout, but it was useful.

I was wondering: would it be helpful to do the same on a DE1? That would give us true "stop steaming on temperature" as the tablet app could connect to this over bluetooth, and stop steam at the right moment.

There are some serious downsides, though:

• cleaning up after steaming will be more difficult since the probe will be attached
• battery life is about 170h, or one week, if left always on.
• However, I believe it is USB charged, and I'm asking Mingle if it can be left on permanently if attached to a power supply
• it's likely this will fit on a thermometer clip, if you were willing to put it on a milk jug. But that becomes something else to clean.

Damian's DSV2 and DSN3 skins already feature automatic steam stopping, by calculating the desired temperature difference, and dividing by heat transfer/second, which is constant on the DE1. However, with different heaters coming out, and milk sometimes at different starting temperatures (ie, out of the fridge vs on the countertop, warm vs cold milk pitcher) that approach doesn't work so well in a cafe.

Would love to hear your thoughts...!

-john

[>decentespresso]

New Decent Heaters



About 18 months ago, I was contacted by Kawai and told that they are the world's largest thermocoil manufacturer, that they make models for a few big name pro espresso machines, and that they'd like to work with us to design a heater to our needs.

Our Decent Espresso Machines are "heat on demand", or boiler-less. However, our machines aren't "sitting around cool", but instead have 1.2 meters of stainless steel tubing, coiled tightly inside a block of aluminum, sitting at 110ºC (for espresso) and 160º (for steam). That's our stored energy.

We currently have two limits imposed on us, by the fact that our demands are beyond what anyone else is doing. The maximum power heaters we can get are 1350W, with 1.2 meters of coiling. This limits us in two ways:

1. our maximum flow rate for espresso is 8 ml/s. Pro machines are typically around 10 ml/s to as much as 12 ml/s. This matters mainly for espresso making styles that want to hammer the puck quickly with water.
2. our steam is about half as powerful as a pro machine, so you need about 40 seconds to steam milk that would take 20 seconds on a La Marzocco Strada.

For the past 14 months, Decent and Kawai engineers have been working on a new design for heaters. The main changes are:

• 2 meters if stainless steel tubing
• standard wattage of 1500W, with test models now in our hands, going up to 2200W
• 30% taller
• but the overall assembled size stays the same, because we've also designed molded insulation to fit efficiently around the heater
• each heater used to take us 90 minutes to hand build (top photos). We would build a case, add aerogel insulation, temperature probes and triple thermal safeties (two thermal fuses, one thermostat).
• Now each heater comes ready-to-use, with easier mounting as well.

We're now testing the 1500W models, as we plan on using them in production for our upcoming v1.3 models. That represents an 18% power boost over our previous heaters.

Through 2020, we'll be testing and refining our control software, with the goal of releasing higher powered steam and faster flow rates, in our 2021 espresso machine models. It's alas not so simple as just increasing the wattage. Heat transfer is a complicated affair.

What's interesting about this progress is that it was impossible to short-circuit this step, and launch 2 years ago with this. A company this size only co-designs products with a company it believes is worthwhile. We first had to prove ourselves.

-john

[>decentespresso]

Beautiful café coming together in Austin, TX, at Celadon Coffee. Two of our black DE1XL nicely countersunk.

[>decentespresso]

Drip tray cover progress

After several attempts at a "lost-wax process" stainless steel drip tray, even with the cross bars, the result is too wonky to be acceptable.



Here's a photo (top) of the final attempt, compared to the current chrome-plated aluminum drip tray cover. Hopefully, you'll agree that our current cover is a lot nicer looking. It's main problems are (a) it's aluminum, and can tarnish and (b) the company that made them for us tried to hold us hostage.

So... we're giving up on "lost wax process" molding for this piece.

I will mention in passing that the supplier has been honorable throughout this time, and promised to refund our money if they couldn't succeed. That's a big loss of money for them, since the molds have been made, used, and aren't useable. We'll definitely do business with them in the future, for parts where lost wax molding is more suited (ie, parts that can be machines afterward, to remove the casting defects).

We decided to reach out to manufacturers of traditional drip tray covers, but to design something that looked less like a BBQ, and closer to our existing design.

We paid for 5 suppliers to send us samples. I've previously posted the *horrible* first sample we received. The rest of the 4 samples have taken more time to arrive, but the workmanship is much improved. All of them are a bit too large, and 2 of have a slight wobble to them. The one on the bottom right is my favorite.



However, there are two manufacturers who are really close to acceptable, that we're going to follow up on.

I've included one photo below of the new design, on the DE1XL countersink. Except for it being a tad too large for the ceramic underneath it, I think it looks ok.

The price for these is much lower (around $5) and being made of stainless steel, they're very tough. They're heavier, so will cost more to mail to people. But overall, I'm pretty happy with how this is turning out, even if we've been sweating daily since August (!!!) about this part.

Thankfully, so many customers sent in their ugly-but-still-functional spare old drip tray covers in, that we've been able to continue shipping espresso machines, with the promise of a free gift and a much better drip tray soon to arrive.

I'm optimistic for a happy ending to this story.

-john

[>decentespresso]

The story behind our digital milk thermometer

We're almost out of stock of our first run of 3000 digital milk thermometers.

I designed these 3 years ago, with my Portuguese designer Joao Tomaz, based on a meat thermometer https://www.mingle-instrument.de/et578a/ design that German thermometer maker "Mingle", already manufactured. Here's what their meat thermometer looks like:



To morph their thermometer into ours, we:
- changed the probe length
- changed the firmware to appropriate temperatures for steaming milk
- added a silicone sleeve for water-ingress-prevention
- changed the printing

But otherwise left the rest alone, since it was a well made product already.

I picked Mingle because they made my favorite oven thermometer (for roasting meats), and it was the only one that had survived my use.

However, steam ingress has been a persistent problem for us. Very heavy milk steaming (or washing up in a sink) gets water inside. The thermometer shorts out and doesn't work.

Luckily, the thermometer is not permanently broken when this happens. You have to twist to open it up, and let it dry overnight with the batteries removed, and it comes back to life. Still, that's inconvenient.

Home users rarely have this problem (not enough heavy use) but it's been a problem for us, when our thermometer is used in cafes.

Before re-ordering, I challenged Mingle to try to address this issue.

They suggested that the PCBs be "nano-coated" with a water resistant coating.

Yesterday they delivered 3 samples to us, and I asked my engineer Alex to run them through ever-more-punishing tests.

I didn't expect them to survive the total-immersion test, but they did. I'm pleased. Only $0.80 extra cost to us oer thermometer, and so much more useful.

We'll have these new models in stock, by the end of December.

The milk thermometer page is here:
https://decentespresso.com/milk_thermometer
if you want us to hold your order until the new ones come in, please say so in the "Notes" of your order.

-john

[>decentespresso]

Lost-Wax Stainless Casting: good, but not good enough

We just received the polished, "as good as it gets" attempt from the lost-wax folks trying to make a stainless version of our drip tray. They don't think they can do better.

It's almost-but-not-quite good enough. The occasionally distortions are very noticeable due to our repeated parallels lines design.

The cross-bars certainly helped, but not enough.

So, for now, we're proceeding with the welded-wire design you can see in my recent other posting.

-john

[>decentespresso]

Decent Coffee Cart Progress

I've previously written about my experiments converting a $99 IKEA BROR tablet into a coffee cart. We've now moving to the next stage in our experiments.

We're having a new tabletop made for us, with computer-controlled-CNC, so that all our coffee components fit into the table, with no sawing needed.

My idea is that we'll sell this at our-cost-plus-shipping, and you'll put it into a IKEA BROR table that you buy locally.

By using CNC, we'll be able to offer a few different configurations. Possibilities such as a left-hand-oriented, or right-hand-oriented layout. Or a larger BIGGER BROR version with two countersunk Decent Espresso Machines. Or with a combination countersunk steam unit/pitcher rinser instead of our simpler pitcher rinser.

With the tabletop we chose, we greatly thickened the top, from IKEA's 8mm to 15mm for ours. We also went with pre-varnished wood, so it's ready for you to use and fairly water resistant.

The CNC cuts are much more precise than I was able to do with a jigsaw.

One effect of that precision is that we were able to put a wider "margin" on the right hand side, where I was intending on putting customer drinks.

Next steps are: power stripe, cable management, receiving a Niche Coffee grinder for this project, and wiring it all up.

-john

[Sullo]

I love this thread, I was asked the other week if money was no object what machine would you get, I said GS3 or Johns DE1
Until that day I can pull the trigger Im off to IKEA tomorrow to buy a bror cart(149AUD) to fit my new jug rinser and flowjet system to it inspired by this thread
The cart will just have to suffice with the new sette and grimac mia in the mean time until I can get my grubby paws on one

love reading about the development of this machine and thank you for sharing and being so open about it all!

[>decentespresso]

Think small

Decent Espresso is currently at the big annual Korea Coffee Show, with 5 staffers and we’re maxed all day. Shin made two Ikea BROR coffee carts, with a 1 countersink machine on a small cart, and a larger cart with two machines (2nd photo). Martin from Niche is presenting tomorrow at 3pm, at our stand.

Shin didn’t tell me what he was designing for the stand, he just got on with it. This is my first look at the backdrop.

I don’t know if Shin intentionally is making a reference to the super-famous Volkswagen mini ad that changed the advertising world, 50 years ago.

-john

[>decentespresso]

App update: favorite profiles, user-created lever profiles

• [*=left]your "top 3" most used espresso profiles are now automatically labelled with a heart symbol.
  [*=left]The reason I added this, is that I find it very hard to find my favorite profiles among the long list. I hope the heart symbol helps.
  [*=left]My goal with the way I've implemented this, is for it to not cause you to have to think, nor be distracting or in your way. Subtle, but helpful. Hopefully.
  [*=left]if you have never used 3 different profiles, then (in this order) these 3 profiles are marked with a heart, to recommend them (especially for new users): "default", "gentle and sweet", "blooming espresso". The goal is to guide new users to the most popular profiles. But once you've used 3 profiles of your choice, the heart icon follows your choice.
  [*=left]the "top 3 profiles" is only calculated when the app starts, and is not dynamically based on your espressos in the current session. I may change that in the future and make it dynamic.

Also:

• [*=left]I've added the "advanced lever profile" created by John Weiss and Damian Brakel's extremely popular Londinium R profile.
  [*=left]I've added Spence's popular "Dark Theme" to the built-in themes in the app, so you no longer need to manually download it. You can see it often in instagram photos of people's Decent espresso machines.

[>decentespresso]

DE1XL: countertop or countersunk

People often ask me if we have a version of this espresso machine that can sit on a countertop, as they don't want to cut a hole in their table. Yes, we do, it's the same model.

So... we made this very short video to show the two ways the DE1XL can be placed at your place. :-D

-john

[>decentespresso]

I received photos this morning, of a big banquet for Heritage Radio that Ace Coffee Co ran in New York. Very nice to see a big production setting with our little espresso machines. Nice one, Charles!

https://heritageradionetwork.org/ https://www.acecoffee.co/

-john

If you don’t know HRN, their radio program on foods are really something:

“HRN is the world’s pioneer food radio station. The studio broadcasts live from two recycled shipping containers inside Roberta’s Pizza, an innovative restaurant at the epicenter of Brooklyn’s culinary renaissance”

[>decentespresso]

Tinkering with colors and controls

We're finalizing how your interaction with the new group head controller will work. Here you can see me telling the machine to heat up, after which a closewise red LED fills the controller as it heats up to 100%. Next to do: an equivalent "cool down" animation. Every typical action you'd need to do with the tablet, you'll now also be able to do with with the controller on the group head.

-john

[>decentespresso]

Put a lid on it

Our 2 liter ceramic water sits a few millimeters under the legs of the espresso machine. Not much can get in there, but an enterprising little insect could, depending on your climate.

Ben has designed a lid that can be 3D printed, that fits on the water tank. We're going to open source the design, so that others can tinker, as we'd like this lid to be as uncombersome as possible. Maybe, an hinged opening is possible, like the sous vide lid in the photo.

Besides people 3D printing it themselves, we're thinking of making these out of food-safe silicone.

Another idea: most water tanks that sit at room temperature eventually grow some algae. Someone suggested a fish tank UV light. I'm wondering if anyone has tried plunging one of these in your espresso water tank, to prevent anything from growing?

-john

[>decentespresso]

Comparing drip tray covers

Today I received samples of all the drip tray covers we're considering.

I was very surprised by what I found.

At first blush, the "lost wax" (cast stainless steel) cover looks "more imperfect" than the "welded wires" one.



However, in actual use, the viewing angle and background has a huge impact. The "welded wires" looks more imperfect in use.

I made a movie comparing the two.

The "lost wax" cover I received was less nice than this, when I received it. However, 6 little adjustments with a dull screwdriver (about 30 seconds work) and it looked much better.

What I think we're going to do next is ask the "lost wax" people if they'd be willing to make manual adjustments like this, using a jig (of our making) that mates with a cover, and repeatedly adjusting the cover until it fits properly into the jig. I don't think it'll take much time, and the result should look pretty good.

I was hoping for "perfection" but at the HOST Milano trade show I looked at other welded wire covers from other espresso machines, and all of them look "so so", aka imperfect, a bit shabby.

The polished finished on the "lost wax" is *beautiful* and catches the light in an amazing way. I hope you will be able to see that in the video above.

Ben placed the two vertical wires so they they center a cup under the group head, which I find quite pleasing now.

Now... the bad news. "lost wax" casting is a slow process. It'll likely take us 3 to 4 more months to get a batch of acceptable covers using this technique. So, I'm going to have to order 500 pieces of the best of the "welded wire" covers, to ship with the upcoming v1.3 machines, or else we won't be able to send espresso machines to customers.

My intention is to continue to work on this part until we're happy with it, and then replace the trays for everyone since August 2019, as well as everyone who sent their (ugly) trays in to help us out.

What do you think?

-john