Decent Espresso Machines (DE1) - Any thoughts?

[>decentespresso]

Packing up the R&D Area



For the past 3 years, we've mostly lived in one 3000 sq ft space, where all our espresso machine R&D has taken place.

Now that we're moving into proper manufacturing, we're taking away two work tables to move them into the newly-rented factory space. The reclaimed space will now house ceramics, touch tablets and give us more warehouse space. It's amazing how much space the "components" that go into an espresso machine take, because of all the protective packaging around each part.

The custom-made cardboard shipping boxes arrived today.

[>decentespresso]

Knockboxes finally shipping



The knockbox that Joao and I designed a year ago, is now finally shipping. Boxes are queued up today from the preorders, and we have another 370 in stock. https://decentespresso.com/knockbox

As I've documented here, there have been a number of manufacturing challenges because of the unusual shape and my choice to make it out of 3mm thick aluminum rather than molded plastic. It holds a fairly large capacity (about 25 pucks) because we make a lot of coffee in the office and nobody likes to empty the knockbox "compost" out.

Because the knockbox is black powder coated over a large surface, about half of our stock is cosmetically perfect. I've decided that if there is 1 imperfection, I'll discount it 30%. 2 or more imperfections means 50% off.

I've attached two photos showing the kind of imperfections we're seeing. Typically it's a scratch or a variation on the black color (a "blotch"). Sometimes there are some scratches on the knockbar because the hole was slightly too tight.



I know that some people advise only selling "absolutely perfect" products for "branding reasons", but (a) I dislike the waste and (b) some folks are happy for the discount and plan to bang the hell out of our products anyway, so they'll soon be imperfect in real use.

If you like buying things on sale, look here:
https://decentespresso.com/sale

[gc]

I've been wondering how the bluetooth scale development is coming along too. I've been hoping it might be ready by the time my certified DE1+ is ready for delivery so I can get them together.

[>decentespresso]

I've been wondering how the bluetooth scale development is coming along too. I've been hoping it might be ready by the time my certified DE1+ is ready for delivery so I can get them together.

The "Skale 2" that we sell will work with the DE1+
https://decentespresso.com/scale

but our Decent Scale is on an indefinite "6 months away", as we won't devote significant focus to it until espresso machines are regularly rolling out of here.

[gc]

The "Skale 2" that we sell will work with the DE1+
https://decentespresso.com/scale

but our Decent Scale is on an indefinite "6 months away", as we won't devote significant focus to it until espresso machines are regularly rolling out of here.

Thanks for that update. Maybe I'll just pass it around to my family as a Christmas present suggestion for 2018.

[>decentespresso]

High Voltage Tests and Tethering Experiments



According to the UL safety standard, every machine assembled needs to be tested to make sure there is virtually no electrical leakage that could cause a shock. Wikipedia has an easy to read explanation https://en.wikipedia.org/wiki/Hipot of this. A piece of specialized test equipment known as a "high pot tester" arrived this week Products - SHENZHEN MEIRUIKE TECHNOLOGY CO.,LTD.


My three electrical engineers reading through UL's excellent essay on the theory and practice of this "dielectric voltage withstand test" https://library.ul.com/wp-content/up...Test_v5_HR.pdf

You can see Parry in the bottom right photo, with an absolutely enormous red plastic probe, gingerly approaching a DE1 to do the first test while Stanley stands safely back.


CATERING KIT & DE1PRO
On the top right photo, you can see Alex testing pumps for the "catering kit" that plugs into the DE1PRO models. I wanted to make sure that the pump was strong enough to lift was 2 meters up into DE1PRO to refill it. We use the Basecamp forum software to record all this, and Alex is making a video and timing the flow. In the end, this pump (that we'll likely use) lifted water 2 meters high, at a flow rate of 1 liter per minute.


WATER MIXING ASSEMBLY
On the bottom left photo, you can see us starting to put together the water mixing assembly. This is the most complicated part of the machine, with 4 valves, 9 temperature probes, and a pressure sensor. You can see a few of our color-coded temperature sensors on the left side of the photo. I'm not entirely happy with how the color-coded sheath is looking after cutting + melting with a heat gun. The ends are a bit messy looking. Yesterday I ordered a "hot wire knife" https://www.aliexpress.com/item/220V...21860906.html? which I believe is the correct tool for cutting the mesh, and hopefully will give us a cleaner result.


ANTI-THEFT CABLE
I received the "anti-theft cable" yesterday (middle right photo), and today wired it up in various ways. Just a reminder about this: it's both for cafes who don't want to have their tablet stolen, and as a backup solution if Intertek requires us to prevent removal of the Bluetooth tablet for safety compliance reasons.

This cable has a bit that fits into the headphone jack. It's tightened and removed with an included screwdriver with a square "inverse Allen wrench" end to it. I like that it's nondestructive, but I didn't like that it doesn't fit tightly. If you overtighten, the screen starts to push away from the chassis.

I like that the other end can be secured with a 3M glue pad or with bolts. The advantage of the bolts is that this could be secured non-destructively to the back panel (middle top photo). If you didn't want the cable, you'd take the chassis cover off and remove the bolt, with no lasting damage. However, there is a dangling cable with this approach.

If the 3M glue pad is used, a very short lock cable could be specified, and the lock becomes almost invisible (top left and middle bottom photos).

Since the tablet has a stand glued to the back of it, I'm thinking that this would be a more invisible place to tether a locking cable, instead of on the headphone jack, which is both visible and not tight fitting or all that secure.

That brings us back to the original tethering proposal I made a few days ago, but with the cable going straight back and into the chassis at the back left (where it is on the top row, middle photo). The advantage of this approach is that the cable is not mostly invisible from the user's stance in front of the machine. Also, the security cable can be completely removed with a pair of wire cutters (off the tablet stand) and from the inside of the chassis (with a Torx screwdriver to remove the cover).

[>decentespresso]

chained to the idea

I've just now ordered 5 different styles of black chains to see which style we prefer. To comply with Intertek's request for a tether for safety compliance reasons, we could simply run the chain from the tablet stand to a torx screw on the back panel. It's my belief that a locking cable tie on the tablet stand would likely comply, as it's only removable with wire cutters.

Here's a photo of the concept, put together now.



We have a slight concern that taps on the tablet could cause metal-moving noise, but that didn't happen on the mockup we just did. But we'll watch for that.

https://www.aliexpress.com/store/product/Free-shipping-bracelet-necklace-material-DIY-accessories-Jewelry-parts-iron-chain-3-5-5MM-SMM1066/1016256_32463314658.html

https://www.aliexpress.com/store/product/Free-shipping-bracelet-necklace-material-DIY-steel-chain-accessories-Jewelry-parts-brass-chain-round-3-3/1016256_32455287982.html

https://www.aliexpress.com/store/product/Free-shipping-bracelet-necklace-material-DIY-steel-chain-accessories-Jewelry-parts-brass-chain-5-5-7/1016256_32458185495.html

https://www.aliexpress.com/store/product/Free-shipping-bracelet-necklace-material-DIY-accessories-Jewelry-parts-steel-chain-4-4-5mm-silver-smb1087/1016256_32447546503.html

https://www.aliexpress.com/store/product/Free-shipping-bracelet-necklace-material-DIY-steel-chain-accessories-Jewelry-parts-brass-chain-4-10mm-anti/1016256_32403846359.html

[fredrodrigues]

Decent team,

Would simultaneous steam/brew feature be as simple as a future BIOS, software upgrade for DE1PRO+ (220v / v1.0) or would it be a parts/component limitation to it?

I've been fascinated with your machine and have been watching /reading pretty much e-v-e-r-y-t-h-i-n-g about it for the past several weeks. I only struggle with the fact that it doesn't steam and brew simultaneously (and I understand the reasons why). But I remember reading somewhere that the DE1PRO+ 220v could have enough power to feature steaming and brewing simultaneously, hence the question...

[HBDecentRefugee]

Chain Free

The fourth of the five chain samples is not too bad. Chain is by its nature, abrasive. I would suggest instead coated wire rope ("aircraft cable".) It is available in very small diameters (like a tiny .35mm) with clear, black or colored plastic coating so as not to be abrasive. Here are a couple of examples:

https://www.aliexpress.com/item/50me...58403965.html?

https://www.aliexpress.com/item/Whol...46371185.html?

Pick the diameter for your preferred aesthetic since strength is mostly irrelevant for this application.

[>decentespresso]

Would simultaneous steam/brew feature be as simple as a future BIOS, software upgrade for DE1PRO+ (220v / v1.0) or would it be a parts/component limitation to it?

The water path can't support it, because we have two pumps (hot and cold) to make espresso, and those are therefore busy whilst making coffee, and not available for steam. A 3rd pump would need to be added.

I've been fascinated with your machine and have been watching /reading pretty much e-v-e-r-y-t-h-i-n-g about it for the past several weeks. I only struggle with the fact that it doesn't steam and brew simultaneously (and I understand the reasons why). But I remember reading somewhere that the DE1PRO+ 220v could have enough power to feature steaming and brewing simultaneously, hence the question...

At 220V we can either give you great steam w/o espresso at the same time, or OK steam during.

The reason I've been avoiding steam-during brew is that steam that had inconsistent power (depending on whether you're making coffee or not) would very annoying.

We'd assume (incorrectly) that we'd be allowed to have two 220V plugs in to overcome this, but for safety reasons we've learned this is not allowed. Thus, steam during brew will only be possible with a separate, dedicated (small) steaming unit.

-john

[>decentespresso]

Chain Free
The fourth of the five chain samples is not too bad. Chain is by its nature, abrasive. I would suggest instead coated wire rope ("aircraft cable".) It is available in very small diameters (like a tiny .35mm) with clear, black or colored plastic coating so as not to be abrasive. Here are a couple of examples:
https://www.aliexpress.com/item/50me...58403965.html?
https://www.aliexpress.com/item/Whol...46371185.html?
Pick the diameter for your preferred aesthetic since strength is mostly irrelevant for this application.

Thanks for the recommendations. I'm hoping that the paint on the chain (I ordered matte black) will make it non abrasive.

I previously avoided the black-wire route because the cable doesn't "flop" pleasantly onto the case, instead keeping its odd bend. Also, how to fix the rope to the tablet and back wasn't obvious. A grounding tab would work, but didn't look great.

We're using m3 torx screws, so I specifically looked for chains that had an internal diameter where the torx screw could simply hold the chain down. That way, one screw that currently holds the plastic back panel on, would get a chain link segment and we'd be good to go. And easily removed.

-john

[>decentespresso]

Just about to power up our first two machines, with everything built right. Both machines are "splayed open" so that we can poke around with oscilloscopes and multimeters to ensure everything is working as expected.

Next week, Ray can hopefully start work on final firmware calibrations now that all components are final-final.

[fredrodrigues]

Thus, steam during brew will only be possible with a separate, dedicated (small) steaming unit.

Plans for Decent dedicated steaming unit?

[>decentespresso]

Plans for Decent dedicated steaming unit?

Very much so, and currently being worked on by Ben and Ray as a high priority. Ideally, we'll have it in beta around the same time that we have the DE1CAFE start shipping (April). It's essentially an espresso machine with a water heater and group head removed.

It will still talk bluetooth, as we want to have "steam profiling" as a feature, so that you can choose your mix of pressure/flow/temperature for steam. This has a surprising effect on the taste of the milk.

-john

[>decentespresso]

Cabling Love



Enough custom-made electrical cables for 350 espresso machines arrived today (yes, they're VERY late in their delivery). We've been making these cables by hand for machines so far, which is time-consuming and error-prone, so we're really happy to receive these.

Each power cable in our espresso machine has a different connector on it so that it's literally impossible to wire it up incorrectly. However, that means each cable is different and custom-made, too.

Clockwise from top-right:
- two pumps: hot and cold water
- one group head heater
- two heaters: espresso and steam
- centralized (8 pin) cable to turn all the valves on/off (water routing)
- small cable to engage the relay to give full AC power the machine, as controlled by the logic board