Decent Espresso Machines (DE1) - Any thoughts?

[>decentespresso]

Here's a link to an "Advanced drilling tips" article that I found excellent, with some choice bits quoted below:
Diamond Drill Bit Drilling Techniques

diamond drill bits are specifically designed for use on very hard materials as shown in the materials section. The extremely hard nature of the materials requires that the diamond drill bits be used with proper drilling techniques. Improper use can overheat and damage the drill bit and may also cause heat fractures and material breakage.

When drilling in hard, abrasive materials such as limestone, sandstone, hard ceramic and porcelain tiles, marble or granite, it is critical to have lots of lubrication. With these hard materials, it is common to drill under water or to have a small amount of water constantly running over the drill bit and bore hole. In either case, the "pumping" technique described below is needed to assure water reaches the very tip of the bit.

Pumping Technique: No matter what lubrication method is used, a periodic "pumping" action will significantly improve lubrication at the drill tip. Because of the pressure on the drill tip, water has trouble reaching the very tip of the drill bit. A "pumping" technique allows lubrication to reach the very tip. While drilling, merely raise the drill up and down a fraction of an inch once in a while as you drill (maybe every 15 to 20 seconds or so). This assures that water enters the drill tip area completely and fully lubricates the very tip. Pumping the drill improves lubrication at the tip and will improve drill bit life considerably.

Drill Pressure
When using diamond drills, it is very important to have only light to medium pressure on the drill and to let the bit "drill at its own speed". Increasing pressure will not speed up the cutting noticeably, but it will increase the friction considerably and quickly cause the bit to overheat. This not only burns up the bit, but it also heats up the surrounding surface and can cause heat fractures or breakage to occur.

[>decentespresso]

I would contact Bosch and Sutton (and maybe Irwin) as the drill manufacturers that have undoubtedly run into this problem many years ago and solved it. My current Bosch 10mm masonry drill bit goes through 1/2" thick ceramics like tissue paper (drilling after a 2mm pilot hole) and leaves no "exit wound" that I noticed. I am 90% sure my old Sutton ones did the same. The other issue you may run into - all drill machines are far from equal when drilling ceramics.

The "Diamond Sure" drill bit manufacturer has an extensive section on porcelain, which I found really interesting
Diamond Drill Bit Drilling Techniques

The key point they make is:
When drilling in the newer super-hard tile, using a diamond drill bit is the only reasonable option.

Our drip trays are made from this sort of super-fine, high density porcelain, and not traditional ceramic.

And so far, our drilling is going well (I'm following their suggestion for "lubrication pumping"), with a clean exit being our remaining challenge. We haven't yet shattered a single drip tray, which I'm surprised about.

Ceramic and Porcelain Tile
Ceramic and Porcelain tile, used on walls, counters and floors, has changed considerably over the years. Ceramic tile was first developed with a heat-hardened vitrified glass finish on the top surface. The inside of the Ceramic tile was still relatively soft. Since the tile was easily scratched, manufacturers developed better manufacturing techniques to make the surface finish much harder. The newer Ceramic tile now has an extremely hard surface that wears very well and the inside of the tile is also relatively hard. While this is a distinct advantage from the stand point of wear, the newer Ceramic tile is often difficult to drill without a diamond drill bit.

Porcelain tile was originally developed as an alternative to Ceramic tile, for use in floor applications where usage and wear was more extreme. Porcelain tile is made with various mixtures of materials, normally including feldspar and quartz, which are two of the major components of natural Granite. The use of Porcelain floor tile was generally limited to commercial applications, but by the late 1980's, Porcelain tile use expanded more into residential construction.

In the 1990's, tile manufacturers began to expand their Porcelain tile product lines to include many different styles and many that closely resembled natural stones. Because of the natural stone look, Porcelain tile use on walls and counters became more popular. Finally, in the late 1990's tile manufacturer's developed new manufacturing techniques that made the Porcelain tile significantly harder. As with Ceramic tile, this was a major advancement resulting in reduced wear and very long life. However, many Porcelain tiles are now as hard as Granite and some are as hard as a low grade tool steel. The newer type of high-quality, "super-hard", "Class IV" and "Class V" Porcelain tiles are now almost impossible to drill with the older "spear point" carbide drill bits and generally can only be drilled with a diamond drill bit.

Old fashioned Spear Point carbide bits no longer work on the new type of super-hard floor, counter and wall tiles. Diamond Drill Bits are the Solution.

When drilling in the newer super-hard tile, using a diamond drill bit is the only reasonable option. However, even with a diamond drill bit, the extremely hard material is not very forgiving if inappropriate drilling techniques are used. It is important that good drilling techniques be used. Appropriate drill speeds, low drill pressure and good lubrication are critical. Please review the Lubrication Tip & Techniques and the DiamondSure Drill Speed sections.

I agree with you that the best solution is to have the hole created as part of the mold, and we'll move to that in time. However, there is a minimum order quantity of 2000 parts when making clay parts, and at a $8 per-piece price, that is both a significant investment (plus mold costs), a lot of inventory to store (a container's worth for each design, in expensive-to-rent Hong Kong), and risky as we have thus far only sold 300 machines. I did not want to order 4000 drip trays at launch, and so decided to modify the 2000 drip trays we do have instead.

[TampIt]

The "Diamond Sure" drill bit manufacturer has an extensive section on porcelain, which I found really interesting
Diamond Drill Bit Drilling Techniques

The key point they make is:
When drilling in the newer super-hard tile, using a diamond drill bit is the only reasonable option.

Our drip trays are made from this sort of super-fine, high density porcelain, and not traditional ceramic.

And so far, our drilling is going well (I'm following their suggestion for "lubrication pumping"), with a clean exit being our remaining challenge. We haven't yet shattered a single drip tray, which I'm surprised about.




I agree with you that the best solution is to have the hole created as part of the mold, and we'll move to that in time. However, there is a minimum order quantity of 2000 parts when making clay parts, and at a $8 per-piece price, that is both a significant investment (plus mold costs), a lot of inventory to store (a container's worth for each design, in expensive-to-rent Hong Kong), and risky as we have thus far only sold 300 machines. I did not want to order 4000 drip trays at launch, and so decided to modify the 2000 drip trays we do have instead.

G'day John

My Bosch (and the old Suttons if memory serves) are diamond masonry / multi purpose drills. I have not seen the long obsolete "old spear type" carbides in Oz for 40+ years and have never used them (working since the 70's).

When drilling medical grade stainless steel (more my field), lubrication is also critical. I use a special stainless steel cutting oil* which changes the drilling process from many minutes down to a few seconds. The diamond drill bit remains a lot cooler and also lasts a lot longer. As a partly educated guess, it would probably do the same with the new "hard style" ceramics. Worth a try if your method starts to eat (not so cheap) diamond drill bits!


TampIt
* I cannot remember the brand, however there are quite a few competing ones - PM me if you want the exact details and I will look it up in my shed in daylight.
PS: Drip trays & volume. I would have made the same call. I fully appreciate the problems with starting up a new manufacturing process. I have been involved in quite a few directly and via engineering clients over the years.

[>decentespresso]

Insulating the group head



Final touches were applied today to our "golden master" espresso machine, and it's now done. We've already built two of them, and we have 6 more almost finished.

Our "Decent Advisors" will soon get these machines, looking for any major "whoops!" that we missed. After that, machines will start shipping to our "early adopter" espresso machine buyers. So, my current estimate is early March for machines going to customers. We're not waiting for the beta testers feedback to keep building machine, and my hunch is that most problems they identify can be fixed with a software or firmware upload, over wifi.

Today we added two sets of insulation inside the group head of our "golden master" and made final decisions about the kind of insulation, its shape, and placement. The insulation inside the group head reduces the heat that leaks into the main chassis and also lowers overall power consumption. We've previously found a lot of hot air cascading from the group head into the main body, heating up the mirror-back panel, and thus wasting a lot of electricity. This insulation prevents that.

We're also insulating directly under the group head cover so that you'll never burn yourself by accidentally touching it. On traditional espresso machines, both the steam and group head are burning-temperature hot.

Two nights ago this "golden master" lived on our "shaking machine" overnight and we verified that no connections were loosened.

After the shaking test, we put temperature probes in multiple points inside and ran the machine for 4 hours making "espresso" at 98.5ºC (to create a worst-case scenario). The group head is sitting at 105ºF/41ºC: warm but not painful. With the PC Board fan disabled on purpose (again, worst case scenario) the PC Board area is hovering at 49ºC. As the previous machine sat at 51ºC with the fan on, and our goal was to stay under 60ºC, this is good news. The insulated group head is 41ºC to the touch, also good. Directly inside the group head, we're at 91º, which is good, as we want the heat to stay inside there.

[>decentespresso]

Out the door!



Our first espresso machine to leave Decent (or under my supervision when I've been on tour) went out the door today.

I believe this might be the first time I've photographed the final machine, and you've never seen the machine with the back panel attached, which cleans up the look a lot. Of course, as I'm writing this post, I noticed the silver screws on the back, which really need to be black. There's always one more thing!

Our CEO Bugs Harpley spent the past 3 weeks learning crochet to hand-make our lucky "year of the dog" mascot, using a pattern from the amazing web site Ravelry https://www.ravelry.com/patterns/lib...e-new-year-dog

Our Christmas tree stays up all year long, with each year's hand-made mascot, as well as Chinese symbols of good fortune. We figure we can use all the luck we can get.

[>decentespresso]

A Short Break and a tearful goodbye

The Chinese New Year holiday starts today in Hong Kong, and so we're enjoying a 4-day mandatory pause from work. Our landlord is painting the common-area floors, so even Bugs and I have to not work.

We had a self-imposed deadline to get a final machine shipped before Chinese New Year, and the UPS man just took our little baby away.

Fabrice made "crêpes bretonne au Grand Marnier" for everyone before we close our doors for a few days' rest.

[HBDecentRefugee]

A substantial Milestone! "Now come to heel, Intertek!"

[HBexile2]

You might not see it, but I'm surrounded by coffee professionals. I have a half dozen cafe owners as direct advisors on private forums. We've also studied other drip tray plumbing solutions, and what we're using is used in the almost identical scenario of "tea tray draining".

If you Google search forums about the La Marzocco GS3 drip tray, its plumbing and refilling, and you'll find that this is what people disliked most about that espresso machine. They're an impressive company with decades of R&D behind them, and even they didn't nail it. For example, they used a "nice simple plug" on their drip tray outlet, and it leaked.

How to design the humble drip tray is not a "solved problem".

We can all see you are surrounded by advisors as you mention it all the time, but perhaps you need a different type. IMO you need a specialised machine person on the payroll and that way these small, yet vital details, would not be overlooked. The GS3 drain is certainly cheap and plasticky but mine never leaked when I had it and it was fine and it is the first time I have seen anyone mention the drain plug issue. Also I think you will find that those tea tray fittings require an o-ring or a teflon washer to seal properly on the underside. You can probably get away with wrapping the teflon tape and hope that it seals but it is not the proper way to do it.

The one thing the GS3 drain is not ideal for is in a commercial setting. The way the drain pipe is fixed to the tray is a mistake, as it is important that you can get the tray out for cleaning and be able to clean under the machine. It is much better to have a small fixed drain cup and the drip tray drains into that.

[>decentespresso]

Safely in Seattle



Our first-espresso-machine-out-the-door arrived safely in Seattle. We got a "post-mortem" on our boxing and packaging today.

While the espresso machine arrived unharmed, the same cannot be said of the cardboard.

The biggest problem is that we hadn't planned for the outer cardboard box to get rained on, thereby greatly weakening the cardboard's strength. Two hand-holds tore because of there, whereas here in Hong Kong, we hadn't had any worries about that.

We can also tell that the espresso machine was pushed on a floor, on at least 3 sides, on its journey to us, because those sides are really dirty.

There is a small amount of scratching damage to the inside cardboard box, which we didn't think was possible, but which appears to have occurred through the torn hand-hold.

To prevent this problem in future shipments, we've ordered plastic cling-film to wrap the entire outer box with. This should help minimize rain damage to the cardboard. It will also likely make it stick to the floor, making sliding difficult or impossible so that the box will need to be lifted rather than shoved.

As far as the espresso machine being shipped sideways or upside-down, that's of no consequence, as the machine design doesn't mind that.

[>decentespresso]

We can all see you are surrounded by advisors as you mention it all the time, but perhaps you need a different type. IMO you need a specialised machine person on the payroll and that way these small, yet vital details, would not be overlooked.

FYI my hardware specialist advisor is Mat North, a cafe owner in Bristol, UK who also does custom installations, for instance with Modbar. And of course I get tons of advice from Facebook and the 3 other forums I'm on. But that's not to say that each decision I make is going to please everyone, no matter how many advisors I have. And of course sometimes we overlook things, but hopefully by doing this process so visibly, we stumble less often than we would otherwise.

Also, I think there might be a slight misunderstanding on your part about how I work. When I post things here (and elsewhere) I do so while there is still plenty of time to change any potential screwup (or just improve them).

I post what I'm doing here not as a "fait accompli" but as a "current state of things" and I absolutely intend to fairly-frequently get things wrong.

That's one of the major benefits to me of participating in forums: my screwups are repaired early, before impacting customers.

So: I feel that you are totally correct to write that the drip tray drain method I posted above wasn't very good. It wasn't. It's better now, for the battering it's received. It could still be improved, and will be, with yet more community involvement.

The GS3 drain is certainly cheap and plasticky but mine never leaked when I had it and it was fine and it is the first time I have seen anyone mention the drain plug issue.

With your GS/3 did you ever plumb it, then unplumb it? That was the problem discussed in forums, namely that once the factory-provided plug was removed, putting it back always led to leaking.

Also I think you will find that those tea tray fittings require an o-ring or a teflon washer to seal properly on the underside. You can probably get away with wrapping the teflon tape and hope that it seals but it is not the proper way to do it.

You are absolutely correct, and having received tons of advice now via the forums, we're now using a silicone o-ring on the underside, exactly as you suggest (backed up by a brass washer). We've drip-tested 2 trays so-outfitted, without leaks.

We're currently looking for a rubber plug we can include so that people who plumb their drip tray, can nonetheless "plug up" the drain for when they want to take their espresso machine traveling, and thus unplumb it for a while.

The one thing the GS3 drain is not ideal for is in a commercial setting. The way the drain pipe is fixed to the tray is a mistake, as it is important that you can get the tray out for cleaning and be able to clean under the machine. It is much better to have a small fixed drain cup and the drip tray drains into that.

I agree with you, and my inability to clean out the inside of the GS/3's water tank had a big impact on me, and was one of the reasons I went with a fully removable, porcelain water tank: so that it can be completely cleaned and even sterilized.

-john

[>decentespresso]

Decent at MICE

I'll be at MICE in about a month, supporting Scott Rao with his presentation, and leaving at least one machine with Matt Perger. Not sure who will get the 2nd machine yet, but I'd like it to be someplace open to having visitors try the machine out.

I corresponded with someone a few months ago about sharing their double-sized booth at MICE, but now I can't remember who it is. :-(

If anyone here is exhibiting at MICE and has some booth space to spare (we'll pay for our share), do drop me a note.

-john

[bigdaddy]

So what method have you decided on when drilling the holes into the drip trays to retro fit your drain fittings?

Cheers.

[saintk]

299 to go.

when can we order th next batch?
thx

[>decentespresso]

Dry before shipping



Another small "whoops" was realized by us today, after shipping our first DE1+ to Seattle.

We need to eliminate all water from inside the water tubes before shipping.

Why? Because it's theoretically possible for water to come out of the tube, roll down the bottom, have the machine flipped over again, and for that water to make its way onto the PC boards and cause a short.

It's very unlikely, but it's possible.

Last week, we ran the pumps for 20 seconds, with the water source disconnected, and that purged some of the water. However, some still remains visible between the flow meter and the water pumps.

We thought about this a while, and what we want is a precise temperature version of a hair-drier, hooked up to a tube, pushing hot air through the water intake tube.

I wasn't able to find exactly that, but we do have "hot air guns" here to shrink plastic tubing.

After a bit of surfing, I was able to find a heat gun that claims to be adjustable down to 30ºC. That's important, because the tubing from the water tank to the pumps is silicone, and doesn't want to go over 100ºC.

The plan is to fit this "hot air gun" with one of the accessory size adaptors so that a rubber tube can lead the not-too-hot air directly into the DE1's water intake.

The DE1 is wired such that when power is removed, all valves open. This is a safety measure, so that the unplugged, the system is not under pressure. This should also make it easier to dry the inside tubes out.

If you have a suggestion of other ways we might accomplish this drying task, please speak up.

[>decentespresso]

299 to go.when can we order th next batch? thx

Just as soon as the first independent reviews start appearing on the internet. I don't feel right asking you to "trust us" and to take your money for a new order (it's a lot of money, we're a new company w/o a reputation, and we're very delayed).

I know it sounds odd, but I prefer to make you wait until you get to hear what the people who already bought have to say about it. Then, I'll be happy to take your money.

So what method have you decided on when drilling the holes into the drip trays to retro fit your drain fittings?

Diamond bit, 10mm hole, silicone gasket, 2mm lip protruding, brass washer behind the gasket.

We haven't been able to locate a right-angle drain fitting that is small enough to fit into the space available, so our longer term plan is to design and brass cast our own low-profile fitting. Ideally, there will be a 1mm depression in the newer designed drip tray so that it all can be flush on the bottom. This will take 6 to 12 months to happen, though, as the ceramic needs to be modified and ordered, and then the brass parts need to be designed, cast and tested. As this is all external, I don't see any problem with people who much prefer the newer drip tray drain setup to switch to it when it becomes available.

I do also like the alternate proposal (from here?) of a permanent hole in the drip tray, that goes into a statically-mounted "drip pan". That idea needs to get tested before we settle on a design.

For now, what we've got for a draining drip tray isn't too awful.

-john