Have you contacted IMS for bulk pricing?

I like the look of the insulation and think it is great you are going to. I've always been disappointed that traditional espresso machines don't insulate their boilers which sit there full of hot water. Although I'm a little disappointed you not going to include the lego... Another suggestion is to insulate the lines between the mixing block, manifold and group head. Also, have you made these lines as short as possible so that the reaction time from when the group head calls for a temperature change to when it received it is minimised?

I like the idea of coated insulation, but what about maintenance/repair issues. If you went with a cross ship model as the only option for repair, I wouldn't care. But since you do want to appease the DIY crowd it would be nice not having to cutaway the silicone to get at various heater connection points. One plus of the simplicity of velcro insulation that ECM/Profitec use. On my expobar, I don't think they lined the insulation on the inside, and after 7 yrs the raw insulation seems to have stuck/bonded/fused onto the boiler. If I ever want to replace it, it will require a razor blade. I wonder how silicone will hold up over time? Instead of Velcro, you could use a removable silicone sleeve. But this doesn't address air gaps.

i used this to insulate my smoker. Unfortunately I don't know how durable it is because I gave away my smoker when I moved. There are much cheaper alternatives and different sizes.
https://www.amazon.com/dp/B003HIPC3W/re ... 1_ST1_dp_1

How about a molded silicone "cover" cut in half and banded together with zip ties or something similar. It could be a separate part # and also easy enough for the DIY to remove and replace. I know there are connections coming out from the tank but maybe the seam for the two half could pass through many of the connections. Just thinking here. Also, please keep up updated on the Alfred University ceramic engineering connection and what comes from it. Take care!

Jim

bachampion wrote:Have you contacted IMS for bulk pricing?

Not yet, but also because we'd have to switch several parts out if we went the IMS route (because their filter isn't quite the right fit into our shower), and I don't really want to be sourcing parts from Italy that I don't need to (shipping is really expensive for brass parts via airmail). I'm trying to convince our current manufacturer to improve this shower screen model. They have the tech chops to do it, as they make our precision baskets (and other people's too) with a different technology.

At any rate, we're pretty sure that the water distribution problems we're seeing are due to water coming into the group head through a hole that can be accidentally placed right below one of the shower's hole, giving preferential treatment to that hole. In our new iteration (this week) we're moving the hole into the group to a location where that cannot ever happen.

bachampion wrote:Another suggestion is to insulate the lines between the mixing block, manifold and group head. Also, have you made these lines as short as possible so that the reaction time from when the group head calls for a temperature change to when it received it is minimised?

We're not insulating the lines between components, because all our tubes are made from solid teflon, which is a great insulator. You don't lose much heat in a 1mm wall thickness teflon tube.

In our previous models, we were losing a lot of heat in two places: (a) valves and (b) metal water connectors.

Next week, we're getting valves with nylon mounting plates (instead of brass), which incidentally will help us pass Germany's strict no-lead rules (which brass has trouble passing, though we're still using brass in the group head's water path), and we've removed the need for all the water connectors, by moulding them directly into either the manifolds or the group.

As to the length of the lines: yes, we think we've made them really short by having tetrised the hell out of the internals these past 3 months. That, and the fact that much of what is tubing on other machines takes place in our manifold (mixing chambers) where everything meets, is part of why we're getting good temperature accuracy.

I've experienced silicone becoming "gummy" after several years of exposure to high heat. Perhaps it's the formulation (platinum cured tubing for a hot water supply), but it seems possible that silicone as insulation might not be an ideal long-term application, as cool/straightforward as it sounds. Although "gummy" doesn't necessarily mean "adhered" and gumminess can be cleaned.

redkiosk wrote:How about a molded silicone "cover" cut in half and banded together with zip ties or something similar. It could be a separate part # and also easy enough for the DIY to remove and replace.

It's doable, but not ideal, because heaters change little bits all the time because the manufacturer is fiddling. For example, our 220V and 110V heaters each have things in different places.

However, the silicone we're using can actually be cut with a knife, peeled off, and applied to a new heater. It's just like a movie special FX mask.

redkiosk wrote:Also, please keep up updated on the Alfred University ceramic engineering connection and what comes from it. Take care!Jim

He was supposed to get back to me this week with his thoughts, and then he's off work for a week. I prodded him, but didn't hear back, so I suspect it'll be ~10 more days before I get anything. Unfortunately, because of our time schedule and our need to make progress, I don't know if I'll get information from him in time to apply it. He's a great guy, I enjoyed talking with him, but let's face it, I'm not going to be his top priority, dropping in on him like this.

We're plowing ahead with our own engineering solutions to the drip tray & water thank. We might switch to melanine for the drip tray, because it's lighter and can be made thinner and with better tolerances, apparently. And we have two ceramics companies trying to make our water tank to our revised specs. It might be that we need to ship the DE1 with a heavier-than-desireable water tank (say, 6mm walls) for the first 500 units we make, and then have an improved water tank (4mm walls is what we're going for) for the next 500. Thankfully, the water tank is a very separate component, so it lends itself well to being revved separately.

anakinstoys wrote:I like the idea of coated insulation, but what about maintenance/repair issues. If you went with a cross ship model as the only option for repair, I wouldn't care. But since you do want to appease the DIY crowd it would be nice not having to cutaway the silicone to get at various heater connection points. One plus of the simplicity of velcro insulation that ECM/Profitec use. On my expobar, I don't think they lined the insulation on the inside, and after 7 yrs the raw insulation seems to have stuck/bonded/fused onto the boiler. If I ever want to replace it, it will require a razor blade. I wonder how silicone will hold up over time? Instead of Velcro, you could use a removable silicone sleeve. But this doesn't address air gaps.

For the DYI crowd I have several suggestions, if you decide to change the water heater:
- the silicone insulation peels right off, like a face mask, and if the new heater has the same dimensions, you can wrap it around it
- you can insulate your heater using exactly the same method we did. You'll need some lego blocks, and 30-minute drying silicone that you can buy at Home Depot.
- you can insulate your heater using some other way, such as a foam sheet and some tie wraps.

I agree that with years, Silicone might become "gummy" but if its insulating properties hold, and it's inside the machine, I'm not sure anyone will care.

Any material that is tightly wrapped around a 130°C heater will change its characteristics over the years. Since Silicone is used as an insulator in cookware (such as on frying pan handles, and oven mittens) it feels like a pretty good choice.

My silicone oven mittens are still fine after several years of use.

Woohoo, it's Christmastime here at Decent Espresso! Lots of stuff arrived today (it's saturday here: Hong Kong is on a 6 day workweek).

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/ResourcesForYo ... 199525.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.

If you are considering going to plastic for the drip tray, you might consider a heat resistant nylon (polyamide) base plastic, like PA12, PA6, or PA66 (nylon66 or Zytel). PA12 (Nylon 12) should be good for injection molding. It would be friendlier for skin contact than melamine.

both candy and pastries makers use a flexible molds or sheet silicone
good to 250c in conventional ovens
have zip tied to boilers for over 3 years of 24/7 surface temp 115c
however these are a non-stick type