I would also like to see a user’s manual and a diagram of how it’s plumbed. Where does the hot water come from? Does the user supply their own kettle? Where does excess water go when pressure is released? How does the preheating cycle work?
Yep, you bring the hot water, the machine does everything else! There is a pressure seal directly in the group head that holds the water in at the end of a shot. You can preheat just by pumping water into a cup for a couple seconds, which is around the same as a purge cycle on a traditional espresso machine. The fluid path is kept as small and as insulated as possible to avoid thermal losses or unnecessary water being held in the machine.
I added a pre-release version of the manual to the warranty page! Please excuse any minor errors.
Hang on...you are running a plastic tube to a kettle on your stovetop?? There is zero chance that the water getting to the device is anywhere near the right temperature after going through a length of plastic tubing. As you know, temperature, pressure and grind are the three ingredients that make good espresso. This throws temperature control out the window and would make the temperature wildly swing depending upon the speed and volume of the extraction. Warm up time is crazy too, as you have to boil a pot of water. Most machines take around 30-40 seconds, but Breville has really perfected this and their new machines come up to temp in a miraculous 3 seconds.
Besides that, anyone who has used an espresso machine knows that there's quite a bit of resistance when locking in a portafilter so that it seals properly. This thing looks like it would move off your countertop before the portafilter would lock in. Do you have to hold the legs with one hand while you lock the portafilter or something?
This is the main issue with those hand pull machines that don't have a boiler. It's so so fussy getting the temperature right, you have to warm everything up first then it's a race against time and even then you never really controlled the temps.
Sorry I can't look at your product page from work, but am I getting the correct impression that this machine doesn't have a boiler? If so, my (meant in good fun) suggestion is that you have in fact designed half an espresso machine :)
With all due respect, you have to figure this out since not many people are going to pay $700 for half of what a $100 device can do. Honest advice not a critique. It must be hard not to read the negativity from some comments but this is already a great job that you had done! You just need to continue building on it IMHO.
Yeah but having the water hit the grounds at the right temperature is what separates a great machine from an average machine. Yours doesn't do that. Congratz on everything you've done so far but I am your target customer and won't consider a machine that doesn't also manage the water temperature.
Externally supplied hot water through a plastic tube makes this a non-starter for me. You use almost no plastic (wonderful!), but the little there is has a lot of surface area touching hot water.
Have you thought about making a water heater accessory? I'd be open to collaborating - contact[at]otekengineer.com
That grinder is a thing of beauty. I was going to impulsively splurge until I saw the price (not complaining, you're doing the right thing by launching at a high price point).
> There is a pressure seal directly in the group head that holds the water in at the end of a shot.
Like a check valve? Does that mean that some (clean) water is trapped between the pump's output and the seal at the end of the shot? If so, this doesn't seem so terrible.
One thing I've often found odd about espresso machines is that they all seem to have some mechanism to depressurize the basket when a shot ends, and that this mechanism lets water that may have been in contact with the grounds go through some portion of the machine. What's the point? The pressure will naturally dissipate quite quickly through the grounds unless like kind of pressure-retaining basket is in use.
Basically it removes excess water from the filter, creating less soggy pucks. Easier to clean. I imagine the rapid depressurisation "upwards" may cause the puck to move a bit upwards, again, making it easier to remove.
