Flat burr cost?

Grinders are one of the keys to exceptional espresso. Discuss them here.
walt_in_hawaii

Postby walt_in_hawaii » Feb 12, 2018, 10:37 pm

OK, so the nuovo simonelli 75mm flat burrs are about $200 a set. But there are other sets of flat burrs that look pretty close, also 75mm, doesn't say which machine they are for; but they run something like $33 for a set. ?? why the huge difference in price?
I just purchased a set of burrs (around 64mm) for my old zip, around $44... but its getting long in the tooth and as parts dry up I expect prices to inch higher.

But the 75mm burr set is a relative new thing in the market, yes? why the exhorbitant prices? I'm just being petulant.

aloha,
walt

*sigh*

Postby *sigh* » Feb 12, 2018, 11:22 pm

Not all burrs are created equal. Material, coatings, design etc all can make massive differences in performance and longevity of the burr. So it's really an apples to oranges comparison when you're looking at most different sets of burrs.

walt_in_hawaii

Postby walt_in_hawaii » Feb 13, 2018, 2:31 am

Sorry, I think I will have to (respectfully) disagree with you.
I buy lots of carbide inserts and high speed steel tooling for my mill and lathe, and at first everyone falls in love and spends the extra money for the pretty yellow titanium coated tooling... but after awhile, you start to notice that the coating makes absolutely NO DIFFERENCE in tool life, and you end up buying just the regular bits instead of the expensive coated ones. Now, for coffee beans undoubtedly there will be a huge difference, its a much softer substrate being cut. However, its still tool steel on the cutting side... I would challenge anyone to produce the data which shows it makes much of a difference in longevity.
What DOES make a huge difference in tool life is the aggressiveness of the cutting edges, their cutting geometry. Their shape and how much metal is in the edges vs how much metal is left after accounting for relief angles and how aggressively they 'point'. More pointy cuts better, but wears faster and is more fragile, cannot do heavy cutting. Again, for coffee I think we are talking a hugely different application so my normal expectations are probably skewed enough not to be valid. I certainly don't have much data to go on, as my original set of burrs in my Pavoni zip are still reasonably sharp (and yes, they are uncoated) although I have had it stored for most of that time.
So, about how long have 75mm flat burrs been on the market? Has anyone got any grinders (aside from the monolith) that use them? the grinders obviously exist, otherwise the burr sets wouldn't be available for them... and do all of the cost $200 per set??

User avatar
aecletec

Postby aecletec » Feb 13, 2018, 2:48 am

What do you mean still tool steel on the cutting side?
My impression of these photos is that there's a coating on the edges https://goo.gl/photos/pc4SWVdCJk3zcA2AA

Nick Name

Postby Nick Name » Feb 13, 2018, 4:12 am

My wild guess is that the expensive burr set is titanium and the cheap one isn't.

ira

Postby ira » replying to Nick Name » Feb 13, 2018, 4:17 am

Maybe coated with some alloy of titanium, but burrs are never made of titanium.

Ira

erik82

Postby erik82 » Feb 13, 2018, 6:43 am

Have a look at the Bellabarista review of the Eureka Olympus with stock and Mythos TiN burrs. If the cutting surface is different and tolerances on one burr are smaller then that will have an effect in quality in the cup. I wouldn't want to go with cheaper burrs as burrs are very important for grind quality. There's a lot of topics about Super Jolly burrs aftermarket versus Mazzer and there is indeed a difference and the more expensive Mazzer burrs do give better results.

A harder surface will give a longer burr life and as these burrs take a pretty long time to get broken in I'd hate to do it more than necessary. The coating will also prevent rust on the burrs which would be a positive thing for home use as we don't wear them down in 1 year time. With tools it's much different as there's a lot more force being excerted on the bit which can damage the coating making the coating pretty useless.

*sigh*

Postby *sigh* » Feb 13, 2018, 11:29 am

walt_in_hawaii wrote:Sorry, I think I will have to (respectfully) disagree with you.
I buy lots of carbide inserts and high speed steel tooling for my mill and lathe, and at first everyone falls in love and spends the extra money for the pretty yellow titanium coated tooling... but after awhile, you start to notice that the coating makes absolutely NO DIFFERENCE in tool life, and you end up buying just the regular bits instead of the expensive coated ones. Now, for coffee beans undoubtedly there will be a huge difference, its a much softer substrate being cut. However, its still tool steel on the cutting side... I would challenge anyone to produce the data which shows it makes much of a difference in longevity.
What DOES make a huge difference in tool life is the aggressiveness of the cutting edges, their cutting geometry. Their shape and how much metal is in the edges vs how much metal is left after accounting for relief angles and how aggressively they 'point'.

I feel like you're answering your own question.

As you hypothesize, the coating likely makes a difference with a soft substrate, so there is an advantage is having the tools coated (which adds to cost). Now, this is likely not an advantage for a home user, but it can impact in commercial settings, which you have to remember pretty much all 75mm burrs are meant for commercial settings.

In addition, like you mentioned geometry makes a huge difference. Some geometry's will be more difficult to produce, as some will have significantly tighter tolerances than others, which also drives up cost.

Just like tools, you can have multiple bits for the same general purpose that widely vary in cost, however, they may perform very differently for various tasks as some will be better suited for certain tasks than others.

bettysnephew

Postby bettysnephew » Feb 13, 2018, 12:30 pm

I also agree that the coatings may contribute to longer life while grinding coffee beans which are much softer than metals in general. When I was working in the commercial food industry so much of our equipment was stainless steel that the coated machine tools were somewhat of a waste of time and money. On the other hand true carbide insert cutting tools were superb for that type of work.
Regarding the 75mm flat burrs I seem to recall Denis from Kafatek relating that he was using a burr with a smaller inside diameter that replicated performance of a larger burr (possibly 80mm - 83mm?) due to the increased area that was part of the cutting face.
Suffering from EAS (Espresso Acquisition Syndrome)
LMWDP #586

691175002

Postby 691175002 » Feb 13, 2018, 1:21 pm

walt_in_hawaii wrote:I buy lots of carbide inserts and high speed steel tooling for my mill and lathe, and at first everyone falls in love and spends the extra money for the pretty yellow titanium coated tooling... but after awhile, you start to notice that the coating makes absolutely NO DIFFERENCE in tool life, and you end up buying just the regular bits instead of the expensive coated ones.


These days coatings are more intended to reduce friction at high temperatures. They don't really achieve anything at low removal rates, but modern geometries can cut so fast that evacuating chips before they weld in the flutes and keeping the end-mill cool are your major problems.