A quick update to let you know things are still moving, slowly but surely. We’ve yet to receive all of the beta units back, but we’ve refurbed the hardware we have and are waiting for firmware updates before machines can be sent out again.
Solved: Wet Pucks
One of the bigger hardware issues we encountered during beta was that pucks were wet after extraction. We knew we’d get some wetness using the VST baskets, which are known for being very dose-sensitive, but beta testers were seeing a large amount of water remaining in the pucks, regardless of portafilter basket used.
Though the jury’s out on whether wet pucks are actually a problem, it does make for messy cleanup. We determined that excessive wetness is due to the group head screen sitting too high over the portafilter basket, leaving space for water to collect once the brew cycle ends.
To resolve this, we’ve modified the thermoblock/group head assembly to lower the screen about 3mm into the puck, and changed the check valve design.
Solved: Group Head Dripping
Another issue was that the group head dripped after a shot, and dripped water when the steam mode was active. We’ve reworked the plumbing to include a shuttle valve that keeps dripping at bay (pictured below). The shuttle valve opens the block’s water path to the drain valve without opening it to the group head - sort of like two opposing check valves.
Drip = conquered!
In Other News, UL
We’re also still waiting on our UL designation. All of the tests are complete, and we’re assured we’ll have our number by the end of this week. Of course, we thought all of the tests had already been completed. What happened?
After our last update we got a call from the certification agency saying that one of the tests that had been performed needed to be redone. The test in question consists of running a continuous brew cycle for 5 minutes without water in the machine. If the machine overheats (as UL had expected), the machine gets a “pass.” If it doesn’t overheat after 5 minutes, the test is performed 4 more times, and if it still doesn’t cut off, the machine is given a “pass.”
Our machine didn’t overheat but the test wasn’t repeated, and the oversight wasn’t noticed until two weeks ago when we were notified. It then took a week to determine exactly what was needed to complete the test, and get it on the schedule for completion.
As far as we know now, all UL tests have been complete (for real this time), and we should expect our number designation by the end of this week. Fingers crossed!
Something else we’ve discovered in testing (with the gracious help of a few of our trusty beta testers) is that the pressure sensors actually have a slightly parabolic curve response, not a linear one as indicated in their data sheet (which we foolishly believed!).
We had been using 2-point calibration to calibrate the pressure sensors. This means that, for each machine, we use an automated rig to test pressure readings at known values of 0 and 10 Bar, then do the calibration math to write unique code for each machine, based on its sensor’s performance.
We’re now using a 3-point calibration, meaning that we’re using three data points to describe the sensor performance. This means that the testing will take a bit longer (about 3 minutes per machine), but performance will be more accurate.
We’ve also finessed the PID algorithms for better performance across brew, idle, and steam modes.
The gating items now are the revisions to firmware and completion of the calibration automation suite.
We hope you’ve recovered from your holiday exploits. We’re still here, working with our beta testers to get through testing. After many arduous weeks and many e-mails and calls back and forth, we’re ending the beta test phase and are moving forward!
We’ve gotten a ton of great feedback (some people have written hundreds of words every day since getting their machines - wow!), and we’ve been working with beta testers and our manufacturer to nail down the causes of problems and find solutions.
Below is a non-exhaustive summary of what we’ve been working through. Some of it will make more/less sense depending on your familiarity with the mechanics of these types of machines, but hopefully this gives everyone a bit better idea of the types of problems we saw.
Nothing is catastrophic, and we’ve already solved most of what’s mentioned below.
A Summary of Issues
- Steam timer does not count minutes
- Suggest we change PID adjustment increment to 1, not 0.1
- Suggest we move status messages from the top of the screen to the bottom to accommodate taller users
Temperature Stability Issues:
- Inconsistent revisions of the code installed on machines, so that some PID values are incorrect, causing temperature irregularities.
- LCD ribbon cable not secured to PCB, causing it to disconnect on some units during shipment
- Low-pressure drain tube is too soft and has ruptured on several units (requires better temperature-rated tubing)
- OPV discharge tube is too long, causing potential for leaking
- Steam wand fitting is misassembled, causing potential leaking issue and lack of steam pressure
- D-pad button sticks on some units
We’ve resolved about 80% of the issues brought up during beta, and will continue to work closely with the manufacturer to resolve the various issues - either with design modifications, revised code, or revised assembly procedures to ensure that components are placed precisely.
We’re currently recalling the beta units. We will then refurbish them with the changes we've made and send them back out for a round of verification. If all is well, we'll roll into production!
We know that any additional testing or delay is frustrating, but hopefully we can all remember that it means we’re close! We haven’t discovered anything devastating, but there are issues that need to be completely resolved and tested before we can happily call these ‘final’ units.
Here’s to lots of awesome espresso in 2014!
Just got back from another trip to the West Coast to check on the machines. When we booked the trip about two weeks ago, the idea was to be in San Diego just in time to see the final beta units go out (after several delays, of course). By the time we actually arrived, the timeline for the second beta build had been pushed back further, and instead we spent time meeting with project management to once again discuss why the timelines keep slipping.
What’s the cause? A combination of miscommunications/inefficiencies in the process, and problems setting up the calibration rigs as they transition from manual end-of-line calibration/QC to automated rigs.
What does this mean for you? Today we were informed that the build will happen tomorrow, which means the second half of betas can finally go out and we can wrap up this stage. To clarify, we’ve already had machines in the field, and we think we’ve identified most of the problems.
The silver lining of the delay is that it’s given us time to make fixes to the second build that we learned from the first, including an updated drip tray design, steam functionality optimization, and a few other design fixes that minimize the possibility of injury due to sharp corners, folds or temperatures. Hopefully the second round will serve primarily to confirm the issues we’ve already begun to solve.
This is an incredibly frustrating development and even more hair-pulling and demoralizing than usual as we pass the 2-year mark and barrel into the Christmas holiday. We’re with our current manufacturer now specifically for their UL certification and timeline management expertise, and it’s tempting to try to point fingers, but that’s not productive - we’re all on the same side, and we’re all responsible.
So what actions have we taken instead? We’ve had a series of very serious meetings between our and their executive teams, and have identified several actions to take and inefficiencies to correct to ensure that we minimize the risk of any further delays.
We know that no one wants to see testing go on forever, and it’s tempting to just skip the second beta build altogether. But we are trying to make sure that we’re measuring twice and cutting once, so to speak. Now that it’s the home stretch - especially during the holiday season and the two-year mark of the project - every additional day is more painful than ever. We know that. You know that.
We currently expect all of the beta units to have shipped by the end of the week, and we'll obviously be moving swiftly to try to wrap up beta as quickly as possible after that.
We wanted to touch base with you and let you know that things are moving, slowly but surely.
We’re writing today to let you know that beta testing is under way! We received a ton of emails from volunteers, and the final beta list was created from a balanced group of users with some priority given to the original backer queue, and are sincerely grateful to everyone who reached out to show their continued enthusiasm for the project.
About half of the beta machines have already gone out, and we’re shipping the rest as they roll off the line. As always, it’s going slower than we’d all like, but it’s progress!
Three tweaks made, more to come
We’ve already worked through three modifications to the beta design:
- We’ve added a deburring step to ensure that all of the edges of the machine are smooth - as there were some sharp edges that caused snags when inserting and removing the portafilter.
- We modified the portafilters to have a 15˚ angle at the handle, which makes them easier to insert into the group head without knuckle knocking or knocking the portafilter itself, which can break the seal between the puck and the portafilter basket wall.
- We modified the drip tray to make it easier to lift out of the machine.
We’re already hearing some great feedback on user experience, and once testing is complete we’ll update with a summary of everything that’s been identified, as we’ll likely see a combination of hardware tweaks that need to be made before further machines ship out, and software improvements that can be released as updates while machines are shipping.
Okay, but how's the coffee?
All the feedback we're getting from beta folks is that the espresso the machine is making is great and consistent. Hooray! That's what we're all here for, so hopefully that's reassuring to everyone who's supported the project!
Slow and steady progress, but the end is near!
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