For those of you interested in another tare down of a Baratza Sette here it is.

Similar post on HB about one year ago with a failure the same as mine, but wanted to repost so folks could make up their own minds with the info from these two HB posts.
(Postmortem of a pre-mortem Baratza Sette's motor assembly.).

Purchased my Baratza Sette new in May 2017 and have used it daily without fault or hiccup until last week. Engine would run but burrs would not engage so figured my gearbox failed (it had). Baratza sells a replacement gearbox for $30 plus $10 shipping so I ordered one. Arrived here in AK exactly 3 days later, which was impressive and reasonably priced.

Before I show you the pics... It's important to know what the machine has gone thru and how heavily it's been used so here are those details.
New: May 5th, 2017
Failed: Nov 17, 2020
Days of ownership: 1,292 days.

We drink medium grind (setting 17 on the coarse burr) drip coffee exclusively. Every morning we grind exactly 10.5 seconds of beans to fill our 10 cup machine.

10.5 seconds x 1,292 days = 226.1 minutes to total usage.


Motor and gearbox freshly removed from machine. Very simple procedure.



Side by side comparison of old and new gears.



Inside of the gearbox before tear apart and cleaning.



Used gearbox after disassembly and cleaning



Close up view of the gears



Close up of the bevel gear



Close up of the spur gear



Final conclusions:
To have noteworthy wear on a bevel gear and complete failure of the spur gear after just 226 minutes of normal use is disappointing. I would have hoped for a longer life span. Some folks have really disparaged the plastic parts. Engineered plastics have gotten really good so I frankly didn't mind seeing it, but then again it did fail so in and ideal world I wouldn't have even seen it. It's hard to see in the pics but it almost looks like the spur gear is a bit small as the wear marks on the bevel gear were only on the top 50% of the tooth. I didn't notice any other abnormal wear on the other parts of the gearbox so I think the failure is really limited to these two gear parts.

On the positive note, Baratza had the parts in stock, were reasonably priced, shipped them crazy fast. The repair was very easy and Baratza has excellent instructions and even a video tutorial online. Am I happy, no. Am I really upset, no. Would I recommend the Sette, maybe. If your a bit handy, then this is a good machine with one weakness. If your not handy or inclined to repair things, then this is not for you as it will likely end up in the trash heap within just a few years, which is really a shame because it could be easily fixed.

Baratza.... if your reading this... Nice little machine with some marginal quality gears. Please beef these up a bit.

Cheers and happy brewing to you.
Sofiandme

Kody, I had a similar failure but after shorter period - likely because I was grinding for espresso. My gears looked the same as yours.

I think the problem is that they are not really a bevel gear but a sort of circular rack and pinion. A bevel gear set would have resulted in a more even wear and longer life, but would have put additional radial stress on the burr carrier which would likely have affected the concentricity and affected grind consistency. It could have been solved by some non-plastic additions, but it looks like an engineering trade-off of cost/consistency/longevity.

My guess is that Baratza is well aware of the issue and that's why they are providing outstanding support level to "outstanding" for this product. If you still have it apart, you may want to add a touch of hot melt glue or silicon to the hanging inductors. The grinder's vibration work hardens the copper windings where they pass through the board. They become brittle and snap. Mine did just that, but I fixed it temporarily by unwinding a single loop, re-soldering and adding some glue until the replacement board from Baratza arrived.

Hey Kody,
i just registered to HB so i can reply to your teardown

The settes seem to die because the lower bearing is constantly being pressed down into the lower case when grinding.
I reverse engineered a broken gearbox and noticed the 0.5mm gap which indicates how far the gear came down.
Unfortunately this already is enough to have the small driving gear slipping.
also this massive wear will cause the grind to get visibly coarser within months of usage.
so never keep you sette's grind setting forever, you'll need to set it finer and finer as the steel balls are digging into the plastic...



My plan is to put proper bearings into the gearbox but i need to find some space for an off the shelf ball bearing in the top



As you might have noticed the burr is surrounded by injection moulded plastic and this might be just in the wrong place when trying to turn down the diameter in order to fit the bearing.

Do you have any chance to perform a section cut in real so i can understand where the plastic ends and the metal starts?

So basically you would have to saw this one into two pieces:



i can't do this to mine as i will need it as a prototype for the turning job


will keep you updated if there's any interest in understanding the sette's issues

This is just unforgivable design. Even in 3 years I'd be insisting on a motor & gear drive unit free. And how could one ever recommend a grinder that fails after less than 300 minutes of grinding. Mine failed in less than 2 years. But Baratza sent me the full assembly free. Baratza should have had a new design for this grinder a year ago. It's a shame because it really hurts their rep. I certainly didn't consider Baratza for my current grinder.

Here you go. Send me a PM if you need higher res or some measurements. Not much meat to machine out and insert bearings. The travelling bearing race has relatively even wear but note the wear adjacent to the pinion drive gear on one race and on the opposite side of the other stationary race.

wow, that went fast....


unfortunately that's what i expected

the red marked area would be a standard ball bearing and the green section is a spacer to fill the gap and provide a proper load path into the upper housing.
the needed modification on the blue plastic will split this into two pieces with the upper one being able to spin more or less freely.
probably not too bad at all if i can find a properly sealed bearing.
the white stuff on top is just a felt ring sealing the housing.







this is how the gear tilts inside the case and loses contact to the pinion drive

Here you go w/ some dimensions.

I think that if this were to be successful, you would also need a harder pinion gear. The mis-alignment of the angled teeth on the rack as they mesh in and out with the pinion causes excessive wear. The pinion takes the brunt of it because there are fewer teeth to spread the wear. If you make it too hard, it will wear the rack first. A proper bevel gear, worm drive or a belt may have been more suitable but would have demanded a more robust bearing solution. Cheers and good luck,

Paul

thanks!!


ah speaking of the gears, this is not a wear pattern on the driven gear.
the gear isn't a standard bevel gear. it's crown wheel gear.
these have two different cut angles on the driven gear which appear as some excessive wear due to a misaligned pinion gear drive.
a big advantage of these is that they aren't depending on perfect height settings like a bevel gear.

if there would've been bevel gears inside the sette they might die even earlier.


the pinion gear drive is worn out because the whole driven gear digs into the lower housing and the teeth don't make enough contact when the forces get to high.

cottec, wrt the gears that's exactly my point. Most crown gears are beveled and often have spiral teeth. The Sette's gears are co-planar - this accelerates the tooth wear on the drive gear because the driven crown gear is circular. It more resembles a rack and pinion where the rack is circular instead of linear. I was suggesting that the gear system is designed for longevity - a different drive configuration whatever the chosen drive would need to be designed for whatever axial or radial loads being applied.

I look forward to seeing what you end up doing with yours - I hope you share pics of your process. Perhaps machining out the races and epoxying in metal inserts would slow the wear. You may not even notice the increased noise.

im pretty sure the first steps will be testing an axial bearing underneath the gear and a ball bearing in the top.

i dont think the usual wear on the teeth will be half as bad when the gears stop hopping around (you can actually see this while grinding)

what Etzinger (who, i'm pretty sure, designed the gearbox unit) did was using a simple belt drive for their 2000$ machines.
probably an interesting option for the settes as well if you drill a big hole in the top and use the 4 motor mounts to fit a new base including a tensioning mechanism. then it's all about adding some proper bearing to the naked metal burr and the machine will only require some retensioning or a belt service from time to time

gear ratio seems to be 1:3 this should be easy to do when swithcing to a belt drive