40 seconds is a lot.I hear all kind of grind times on different forums.But 40 seconds for 18 gram...

^ "Ain't no body got time fo dat!"

That's right.I'd rather be getting myself a cold pop.

TomC wrote: What I still cant wrap my head around is this notion that a relatively soft structured carbohydrate via partially cooked dried rice, is going to have any effect whatsoever on any surface as hard as TiN. I don't see how it can be hard or abrasive enough to alter that edge geometry, unless someone is inferring that it's slightly denser mass is transferring friction and pressure to the edges faster than coffee would, and effectively pushing the edges teeth into a more level alignment (akin to the stropping analogy), but I'm still skeptic.

Times like this, its worth a thought experiment to help clarify things. It seems this is a huge source of confusion for many people.

The coating itself is very hard and pretty slippery. But instead of a set of TiN coated steel burrs, imagine that these are TiN coated, fully soft\annealed, aluminum burrs. The term "egg shell" has been used, and while that's reasonably accurate, it does give the TiN coating more strength and stability than I think is really due here in our applications. In essence, the coating is really only as stable and hard as what its sitting on top of.

Now, lets take that last statement one step further.

The coating on the crushing faces of the burrs is extremely stable and will last essentially forever. The force applied per unit area, ie stress or pressure, is relatively low. The large area of the face easily reacts the forces applied to it by crushing the bean. The stress is low, so the deflections are low, which keeps the very hard and brittle TiN coating intact and uncompromised.

Move on down the burr to the cutting edges. The stress, or force per unit area, is now substantially increased because our area has dwindled from a large flat face to a tiny edge. Even hardened steel isnt immune to these repeated forces. The fact that its now TiN coated just reduces the friction a tad, which proportionately lowers the cutting forces. This increases the time it will take for the underlying substrate material, the burr, the begin to bend and deform. Just like what happens with any cutting tool. In essence, industry uses TiN coatings as a means to increase the tool life. While tool cost is an issue, not having to change tool setup is an even bigger deal.

Dont believe a word I'm saying?
The same exact thing happens on a TiN coated drill bit, end mill, or carbide insert.
The coating on the cutting edge will wear off eventually, yet the flute faces will usually stay pristine.
These items work in reverse of a burr, in that they cut first and then the flutes or chip breakers are used to evacuate the chips from the cut. I tried searching for a pic of a worn end mill or something, but had lots of trouble. I have some at home that show this wear pattern, and here we're talking a really hard carbide tool cutting relatively soft aluminum.

There's some very interesting ideas being stated and I think this thread should be broken off for further discussion. I would have missed the whole burr discussion if I hadn't opened the thread.

pechelman wrote:Times like this, its worth a thought experiment to help clarify things. It seems this is a huge source of confusion for many people.

The coating itself is very hard and pretty slippery. But instead of a set of TiN coated steel burrs, imagine that these are TiN coated, fully soft\annealed, aluminum burrs. The term "egg shell" has been used, and while that's reasonably accurate, it does give the TiN coating more strength and stability than I think is really due here in our applications. In essence, the coating is really only as stable and hard as what its sitting on top of.

Now, lets take that last statement one step further.

The coating on the crushing faces of the burrs is extremely stable and will last essentially forever. The force applied per unit area, ie stress or pressure, is relatively low. The large area of the face easily reacts the forces applied to it by crushing the bean. The stress is low, so the deflections are low, which keeps the very hard and brittle TiN coating intact and uncompromised.

Move on down the burr to the cutting edges. The stress, or force per unit area, is now substantially increased because our area has dwindled from a large flat face to a tiny edge. Even hardened steel isnt immune to these repeated forces. The fact that its now TiN coated just reduces the friction a tad, which proportionately lowers the cutting forces. This increases the time it will take for the underlying substrate material, the burr, the begin to bend and deform. Just like what happens with any cutting tool. In essence, industry uses TiN coatings as a means to increase the tool life. While tool cost is an issue, not having to change tool setup is an even bigger deal.

Dont believe a word I'm saying?
The same exact thing happens on a TiN coated drill bit, end mill, or carbide insert.
The coating on the cutting edge will wear off eventually, yet the flute faces will usually stay pristine.
These items work in reverse of a burr, in that they cut first and then the flutes or chip breakers are used to evacuate the chips from the cut. I tried searching for a pic of a worn end mill or something, but had lots of trouble. I have some at home that show this wear pattern, and here we're talking a really hard carbide tool cutting relatively soft aluminum.

Phil, I totally agree with your points, but the sheering forces that the HG-One's burrs, by nature, being a low RPM hand grinder are on several orders of magnitude lower than an industrial tool, drill bit, etc that benefits from higher wear prevention.

I'll go out on a ledge and say, the only thing that interests me about the potential of the TiN coated burrs would be corrosion resistance, since we have to RDT, and long term conclusions can't be made yet as to whether that will eventually lead to rust. I'm hoping the coating of coffee oil will help prevent that, but it's no guarantee. I have no problems with cranking effort now, so I don't need it to be any easier, especially if it comes at the cost of having to crank on it forever.

Mitch, I sorta agree with your point about a new thread, but at this point, most of the topic of conversation revolves around the HG-One's application of this technology and how it affects their grinder.

TomC wrote:Phil, I totally agree with your points, but the sheering forces that the HG-One's burrs, by nature, being a low RPM hand grinder are on several orders of magnitude lower than an industrial tool, drill bit, etc that benefits from higher wear prevention.

I'll go out on a ledge and say, the only thing that interests me about the potential of the TiN coated burrs would be corrosion resistance, since we have to RDT, and long term conclusions can't be made yet as to whether that will eventually lead to rust. I'm hoping the coating of coffee oil will help prevent that, but it's no guarantee. I have no problems with cranking effort now, so I don't need it to be any easier, especially if it comes at the cost of having to crank on it forever.

Mitch, I sorta agree with your point about a new thread, but at this point, most of the topic of conversation revolves around the HG-One's application of this technology and how it affects their grinder.

no argument at all on the forces being magnitudes less, but the wear mechanisms are the same, it will just take longer. No one would argue, at least I dont think, that hardened steel gears will wear faster if you throw in a handful of sand once in a while. Here we have a set of "gears" that are designed to work with "sand" in them. Even things which are soft or have an inherently high lubricity can and are used as lapping compounds, so I dont think to consider coffee an abrasive, is unreasonable. (i dont think at all you're saying that, just wanted to spell that out)

The TiN coating and corrosion resistance I think is a nice added benefit.

Does anyone know what these burrs are made of? I feel like I've seen someone mention 16cn4, but searching the web and matweb turns up nothing for me.

Two things I have been wondering about;

It has been mentioned that these are a different un-broken-in batch of burrs compared to the first batch.
One then wonders, what else is different in these batches. Same material or heat treat? Perhaps a dull cutting tool was used to make these. Maybe they changed coolant which can affect surface finish? Did Mazzer need to retool to fill this large order of burrs from making a different type of burr and something was different in setup? These, and more that I didnt mention, are things we'll likely never know, yet could be contributors to grind time.

The second, and if I'm remembering correctly, I thought someone indicated that after break-in on these new coated burrs, that one will need to adjust them coarser. To me, that makes no sense and I just cant understand that. If this is indeed an accurate statement, I think it could be key to understanding whats actually going on here.


IN The Meantime;
I'm the new happy owner of John B's #003/81mm HG1.
So these grinding time \ burr coating discussions are truly academic to me.

I own #199 with the TiN burrs. Things have improved significantly since when I first unboxed the grinder. I'm getting some lovely extractions but was requiring between 80 and 90 revolutions to grind a 20 gram double. This evening I decided to grind par boiled rice through. I ground 1 kg of rice... what a workout!

Now a 20 gram double takes between 60 and 70 revolutions to grind. I'll have another go with an additional kg of rice in a few days (expect I might be a bit sore tomorrow... age is taking its toll!).

To be frank I'd prefer not to be grinding rice through... but now that I'm certain that I'll get speed to the same level as the original set of HG ones I'm actually very glad that I have the TiN coated burrs. I believe that the new coating will provide improved corrosion resistance... and I will soon have the same grinding experience as all of the owners of the original batch. With a bit of extra hard work at the start I feel like I will be in a good place with this grinder.

It's all been stated before, but the low retention makes this grinder a pleasure to use as a single doser. The physical sensation of grinding is great (I didn't think this would be a positive prior to purchase) and the aromas whilst grinding are amazing.

I'm very happy that I purchased this grinder (although I might have given you a slightly different answer a week ago).

Terence

For reference, I have one of the original sets of 83mm burrs, and I just ground 16g with approximately 22 revolutions.

Enjoyable thread. After reading though every post a few questions come to mind, which hopefully some new HG one owners or Paul/Craig can offer thoughts on:

1. As a few others and I wondered earlier, it seems odd that the recommendation is to move to a coarser grind after seasoning. Is this really the case and if so, any thoughts as to why? It would seem that a finer grind would be needed to get the same flow as a before, not a coarser.

2. If seasoning the burrs levels out the jaggedness of the cutting surface, smoothing out the wwwwwwww pattern as it were, sort of like stropping a blade, why would this decrease lubricity? Why would this evening or smoothing out of the cutter increase grabbiness and therefore require fewer cranks to grind a shot (as has been clearly noted)? I would think that the unseasoned, more jagged surface would grab better, but that is obviously wrong.

3. Part of the TiN process is sandblasting the burrs before applying the TiN deposit. Is this sandblasting enough to smooth out the cutters, a kind of seasoning beforehand, sort of like Mazzer does with their pre seasoned version of their burrs? If so, why is further seasoning required? Are the burrs not already smooth or does sandblasting not address the microscopic jaggedness in a way that only rice or coffee can? Or does the TiN deposit itself introduce a new microscopic jaggedness that requires further seasoning?

4. How does the TiN coating affect static issues that some were having earlier? From what has been posted so far, it seems that the increased lubricity of the burrs reduces static and heat created during grinding. If so, is RDT still necessary?