HG-1; cranking effort is why 2 different sets. TiN made it a non-starter since the 83TiN cranks like the 71 regular burr.

As to why Mazzer makes 2 different sizes? Who knows, unless they have spent lots of dollars analyzing the grounds out of the 2 sets at the 2 different voltages and the 2 different frequencies. They might have...

I just ground some Maragogype (elephant bean) beans with the Hg one. With the 83mm burr set it took 25 turns to grind 14 grams. This is very close to the same number of turns with several other kinds of other beans. Hg one seems to grind at about the same speed from peaberry to Maragogype, at least with 83mm TiN coated burrs.

By the way, it was a good thing that I was the one that got the Hg one with the improperly tapped bore for attaching the handle, since I have a full set of equipment for small size machining. It took me only a few seconds to correct the problem.

The extraordinary workmanship on the Hg one is still amazing. These are not mass produced things! It is a beautiful thing because of its workmanship. It is pretty well devoid of plastic. Even the handles are metal.

Remembering:
1. The 71mm had a lot more static issues than the 83mm
2. The 83mm had to be TIN coated (to make them easier to turn) as the second batch of burrs they received from Mazzer was a little different from the first one: they were made more "aggressive" , meaning these burrs would grind quicker however demanded additional effort (that was imperceptible in the motorized Robur but significant in the HG-One).
3. After some use you get the best of both worlds with these burrs: they stay easy to turn and much quicker to grind.

I believe that these (Mazzer last batch with TIN coating) burrs are more efficient as they're able to "bite" better the beans, once the TIN coating gets a little use and becomes less "slickly".

I totally agree!

The HG-One guys put a lot of effort into getting it right and make a wonderful grinder.

The 83 mm burrs are only available in a Mazzer grinder in their 3 phase, very high volume, Robur

My hg one 83after tin , hard bean below 25 rotation 18g for esp grind setting, dark roast bean below30

I think it is crazy fast, both hard or soft bean within 20sec!

And the taste is excellent

bmb wrote:Remembering:
1. The 71mm had a lot more static issues than the 83mm

I doubt this statement, and it's likely only an unproven opinion. If you were eager to streamline your production to just one version of something, you'll look for subtle "faults" to call out on the one you don't want. But having both examples set up and ready to go at the exact same time showed that both suffered from static, and which RDT solved entirely, so it was irrelevant.

The 71mm were able to get the task done much faster than the 83mm. You folks that are stuck with the newer 83mm will never know how good it is to use the same design with a 71mm burr set.

But hey, bigger is better right? How American

bmb wrote:1. The 71mm had a lot more static issues than the 83mm

This came from the HG one guys themselves:
http://hg-one.com/static-and-what-to-expect/

Nevertheless, I was too late for the 71mm and certainly would have liked to have given them a go.

I'm not so sure that it is "stuck with 83mm" I suspect it is the individual burrs that make the difference. Mine grinds when not full seasoned such that I get 16 grams with about 26 turns, it is also with the TiN aftermarket burrs. It is also easy to turn. Bigger burrs should grind faster, so why do many of them not do so? It might be that the smaller burrs are often sharper. This would make a big difference.

I suspect one would see a visual difference on microscopic examination of the ground coffee from burrs that grind fast, and those that grind slow. (I suspect less dust sized particles with sharp burrs from more cutting and less smashing!)

I suspect there is a clue here: The 83mm burrs originally were used on huge grinders with 3kg/minute or so output, if I be not mistaken. They draw something like 10 amperes with 3 phase 240v. That would be a reason for them to be less sharp in the first place because they probably were thus not designed so much for espresso.

Could it be a case of diminishing returns for espresso grinding, regarding burr size, as you creep over a certain threshold? ie. Beyond 71mm there's little or no payoff for espresso in the cup. And it could actually take longer to grind, to boot.

For example, Compak's entire commercial line uses 68mm burr sets. They don't seem to think bigger is better. And we know how well regarded this line of grinders is around these parts.