[PROMO] LeverCraft Ultra Grinder - Page 33

#321: Post by **Bluecold** » January 28th, 2021, 1:04 am

Plinyyounger wrote:You could ask that question of any manufacturer, I'd suggest if it's within your budget to not worry about things 10 years in the future.

In general, your statement is true. However, in the specific case of servo motors and drives, most industrial manufacturers offer an availability guarantee for 10 years. The part will become 'not current' or 'special order item', and the lead time/price will increase, but the part stays available for at least 10 years. Especially in industry, this is very important, because you don't want to swap out production lines as if they were smart phones.

#322: Post by **PIXIllate** » January 28th, 2021, 1:42 am

Jeff wrote:Any high-end grinder you buy today will be obsolete in ten years. Ten years ago, "high-end" meant a Titan conical. Coffees were very different then as well. There's no reason for me to expect ten years from now will look like today for coffee, extraction techniques, grinders, or burrs.

Ref: Titan Grinder Project

Jeff, I think this is an interesting point and potentially one of the most important factors in deciding where to "lay your money down".

I think things do eventually reach a point where enough is understood about the science of how something works where we are able to stop racing off wildly in all directions. I can see that the science of espresso has advanced greatly in the past decade. In no small part due to the experimentation and discussions run by home espresso enthusiasts such as the people here.

The Decent machine seems to be making it possible to do things in a measured, repeatable way wherby a lot of old and new theories can be tested and layed to rest or built upon.

We may be approaching a more mature phase of espresso making where choosing a pressure or flow profile or grind distribution or puck preperation method comes from a place of greater understanding of WHY these things make the differences they do and less from "its different and I think it better".

It's possible grinders and burr sets at the level of the Ultra and Kafatek are cresting this frontier currently. For his part Hoffman has stated that he feels the next advancement in espresso will not come from grinders or machines but from the beans themselves. Pointing to the work being done to identify species and try them in different terroirs.

Only time will tell and at the end of the day very few people have the passion to want to continue to stay at the forefront of any hobby for a decade or more. Most enthusiasts have a handful of years of deep engagement and then find what they prefer and, to some level, regress into a rinse repeat routine. I think this may describe what had happened to classic Italian espresso before the 2nd and 3rd wave. Which makes the experience of people such as yourself so valuable. You've been engaged at a high level for a long time.

#323: Post by **ira** » January 28th, 2021, 2:32 am

charliemb wrote:Hi Eric

I'm strongly considering preordering for the next round and have a question regarding the motor. Imagine 10 years have passed and you are no longer in business. If the motor or the control box breaks, from where do we buy a replacement?

I understand the question and the worry, But I would point out that the motor in the Grinder will probably take years to get the use it will probably get in it's first week or three of use in a normal industrial application.

Ira

#324: Post by **charliemb** » January 28th, 2021, 11:57 am

Quoting from Kafatek's bullet list for the Monolith MAX (highlighting and underlining added),

Brush-less DC motor made in Japan with 40,000 hours rated run-time and 22-400 RPM speed control and real-time grind speed display geared to deliver 2000W of power.

For durability we have sized our motor so its utilized at 50%-70% of its available torque with 50% utilization most of the time. Components that are not working at their limits last longer.

Stock DC motor and DC driver in standard industry size from large manufacturer with world-wide presence to future proof grinder. We did not use custom components for these parts since design goal is that grinder will work for more than 50 years from now and electric parts that can fail must be standard and available world-wide.

Kafatek's page instills confidence in the component that is most likely to fail. I have no doubt that if I buy a Monolith MAX I can find a motor even after they are no longer in business.

If I buy a Ceado, I don't have to worry about getting it repaired. I wouldn't even need to ask up front. The Weber EG-1 apparently uses a NEMA 34 motor and at least I can look that up. The situation is different here with the Ultra given that 50% of sole proprietors survive the 5 year mark. It's really year six that I'm worried about. And you can bet I expect my next grinder to last at least that long. And I can't be the only one with this question in mind when considering the Ultra.

I'd like to see this addressed for this grinder. Reliability data would be nice, rated hours or MTBF; some statement as to the availability of a replacement motor, etc.

January 28th, 2021, 1:21 pm

charliemb wrote:Quoting from Kafatek's bullet list for the Monolith MAX (highlighting and underlining added),

Kafatek's page instills confidence in the component that is most likely to fail. I have no doubt that if I buy a Monolith MAX I can find a motor even after they are no longer in business.

If I buy a Ceado, I don't have to worry about getting it repaired. I wouldn't even need to ask up front. The Weber EG-1 apparently uses a NEMA 34 motor and at least I can look that up. The situation is different here with the Ultra given that 50% of sole proprietors survive the 5 year mark. It's really year six that I'm worried about. And you can bet I expect my next grinder to last at least that long. And I can't be the only one with this question in mind when considering the Ultra.

I'd like to see this addressed for this grinder. Reliability data would be nice, rated hours or MTBF; some statement as to the availability of a replacement motor, etc.

You absolutely have the right to ask for that, if you do it publicly like her it looks a little bit like you are on the fence already. Maybe consider asking questions like that via email to the seller or manufacturer.
Getting a list of reliability data won't help too much, as the numbers don't mean anything as long as you are not an engineer. I believe the general statement that you quoted is much more helpful for most users. That said I am pretty positive that if you can find someone who can repair a Kafatek apart from Denis, he will be as willing and capable to repair any grinder.

January 28th, 2021, 1:37 pm

Personally if repairability is a real concern, I would stop sugar coating it and forget about all boutiques.
In that price bracket I would buy a Lab Sweet, if I want a hands down all purpose grinder or an EK43, if I feel like fiddling with it a lot and want to try the different extreme burr sets.
For a little less you can get a 80mm Ditting/Mahlkönig grinder which you could get SSP burrs for as well, but the standard burrs don't even need to be swapped out.
Hemro is very unlikely to be put out of business

#327: Post by **Jeff** » January 28th, 2021, 2:07 pm

I understand the concerns, but understanding what part of specsmanship is important and what is marketing fluff is important.

On MBTF or rated life, the first thing to understand is that it is generally calculated from estimates of the MBTF of its components, not tested, except perhaps for a spot check to confirm that an unexpected failure mode doesn't pop up. Further, if you assume 5 minutes of run time a day in home use, you're looking at around 30 hours a year, or 300 hours in 10 years. It is not that it won't fail, but that comparing MBTF or rated life in the tens of thousands of hours isn't going to give meaningful insight into the motor's longevity.

The better question to ask would be if the motor is a standard size and configuration that is available from third-party suppliers. If you can replace it yourself and get the grinder back into alignment is another question that i think you'd be hard pressed to get a realistic answer to.

Reading the marketing fluff quoted, as someone with training as an engineer, increases my concern. Stating that the Monolith MAX is "geared to deliver 2000W of power" seems to be uninformed and misleading, as you can't generate power from nothing. You certainly can gear down a motor to increase its torque, but the power delivered will be lower due to gear-train losses. Claiming that the power is higher seems to be a violation of the basic principles of thermodynamics, unless you're storing energy somewhere when you're not drawing it for grinding.

Edit:

charliemb wrote:If I buy a Ceado, I don't have to worry about getting it repaired. I wouldn't even need to ask up front.

I did try to find the motor for a Ceado E37S, P/N 30120 without much luck.

#328: Post by **Jake_G** » January 28th, 2021, 10:53 pm

A couple of things regarding the servo motor and control box.

But before I do that, I should make a disclosure:

I've been volunteering my time to Eric to develop improvements for the Ultra and other things for the last year or so. We struck up a relationship during his restoration and subsequent upgrades of a Synesso Cyncra last year, and things just built organically from there. I view Eric as a friend and I am happy to donate my time to our collaborative cause of making great coffee more available to the masses. As of today, I have zero financial ties to Eric or LeverCraft, but consider myself close enough to the development of the US release of Ultra that I have been rather quiet about it publicly to avoid any potential conflicts of interest. To be clear, I want Eric to succeed, and we have talked about having a formal business relationship when the time is right. I'll comment below in a technical capacity to provide factual information on the goings on with the servo and drive of Ultra.

There. That's out of the way.

First, the motor and its longevity and life cycle:
As others have said, the Ultra uses an Permanent Magnet AC (PMAC) Synchronous servo motor. The motor is a relatively standard 130mm frame servo used in tens of thousands of light industrial applications. It is often marketed as a CNC servo, due to the high accuracy of speed and position control made possible by the motor and encoder combo. If this motor failed, you could replace it with any other 130mm servo with similar torque and speed characteristics with no issue aside from a few parameter adjustments on the drive. It is not proprietary. To illustrate this, the original 2500 rpm 220V motor did not work satisfactorily on 110V. We were able to find a suitable motor locally and plug it into the big box and get the grinder going without any issue. That said, the 110V servo is less common than the 220V servo and it is preferable to match the motor to your supply voltage to get the best performance.

Second, why the big box?
Servo motors do not work without a drive. The drive takes single phase AC mains power from your home and transforms it into three phase variable frequency (and voltage) output that makes a PMAC motor work. The drive reads the feedback from the optical encoder to determine motor speed and adjusts the driving frequency and voltage to maintain the set rpm. The drive lives in the box. It is big because it has to handle a lot of current to do its job. The servo itself is 1.6kW, which is roughly 2HP. At 110V, this is around 14 Amps the drive can pull, but at low rpm the voltage applied to the motor is lower, meaning the drive can push upwards of 30 Amps out to the motor when drawing less than half that from the wall. As Jeff mentions above power is power and there is no faking that. A 200W motor through a 10:1 reduction gearbox may have lots of torque, but it is not 2,000W. Likewise, it takes some large heatsinks and beefy electronic circuits to pull in 14 Amps, condition it and pump out up to 30A to power a 1.6kW motor. Big power takes big power supplies and they take a big box.

The motor itself is not oversized in a direct-drive configuration, as it simply takes a great deal of torque to grind coffee very finely with large burrs. The decision to go with direct drive was made long before I knew Ultra was a thing. It is the reason the grinder is nearly silent. It is also the reason the grinder is bloody heavy and has a big box. Choices have consequences, good and bad.

The speed controller simply sends a signal to the drive. Telling it what the target speed is and whether or not to run. My Ultra has the speed controller integral to the big box. The newer design has the speed controller separate from the big box. I'm not sure I'd have a preference either way, but the idea of hiding the big box seems as plausible as does plumbing one's machine, and if the big box is hidden, then having a small speed controller seems preferable. While having a nice integrated package would be ideal, the drive is quite large and any attempt to shrink it would then make it proprietary and more difficult to replace should anything go awry. The speed controller could easily be as small as a phone, since it's only sending information, but the big box is doing real work, and that requires real power handling capabilities that demand size...

That's all I've got for now. Cheers!

- Jake

January 29th, 2021, 2:50 am

Jake_G wrote: ...
Second, why the big box?
Servo motors do not work without a drive. The drive takes single phase AC mains power from your home and transforms it into three phase variable frequency (and voltage) output that makes a PMAC motor work.
...
- Jake

I never really thought about why the box is needed. Now that I know I am wondering if it would be possible to get some kind of a different box. Where I live 3 phase is available in every kitchen to power ovens. Would there be a chance to get a different box to plug directly into the 3 phase socket? On the other hand I am unsure if more space in the box is needed for the transformation or for creating the variable frequency. In the 2nd case my request makes no sense

#330: Post by **Jake_G** » January 29th, 2021, 7:24 am

coffeeOnTheBrain wrote:Would there be a chance to get a different box to plug directly into the 3 phase socket? On the other hand I am unsure if more space in the box is needed for the transformation or for creating the variable frequency.

The box is capable of taking 3 phase power as an input. But it would not change anything, as 3 phase power is still "stuck" at 50 or 60Hz. In the case of a PMAC motor, they won't even work plugged into a 3 phase supply like a standard asynchronous induction motor would. Because the rotor has permanent magnets in it, the rotating magnetic field in the stator must be in perfect sync with the rotor. The drive uses the encoder and special algorithms based on the current draw and back emf of the motor (all motors are also generators, so as you apply voltage to make them spin, they apply voltage right back) to determine its phase position, instantaneous torque and velocity. Using this info, the drive is able to precisely match the power output to control the motor.

Because the output is so closely tied to the state of the motor and its encoder, this box wouldn't be useful to other 3 phase devices in the home. Likewise, other 3 phase sources would not be suited to driving the PMAC motor.

Cheers!

- Jake