A proposed alternative to the marker test for burr alignment

Grinders are one of the keys to exceptional espresso. Discuss them here.
coffeeOnTheBrain
Posts: 632
Joined: 5 years ago

#1: Post by coffeeOnTheBrain »

I would like to propose an alternative to the marker test. It is not as popular but I would say more reliable.
Try to find the distance between first touch and complete burr lock. This is measured with the difference in dial position.
If someone is interested I happy to describe the details.

User avatar
ei8htohms
Posts: 142
Joined: 5 months ago

#2: Post by ei8htohms »

Not understanding what the test you're proposing (measuring from lock to chirp) would demonstrate or how it would be diagnostic. Please do share more info.
LMWDP #751

User avatar
another_jim
Team HB
Posts: 13917
Joined: 19 years ago

#3: Post by another_jim »

Lock to chirp is fast, and tells you if there's a problem. But unlike the marker test; it doesn't indicate where the problem lies. Also, the largest acceptable difference may differ from grinder to grinder depending on thread pitch and burr diameter.
Jim Schulman

malling
Posts: 2917
Joined: 13 years ago

#4: Post by malling »

While you can get a rough estimate of a grinder being poorly or good aligned between those points, I don't know how your going about figuring out where the misalignment on the carrier is found without measuring or do the rather unreliable marker test

PPapa
Posts: 188
Joined: 6 years ago

#5: Post by PPapa »

I wonder how difficult would it be to come up with a deflection gauge assembly that fits any grinder? Something that hugs the outside of the burr perhaps?

A bit like radial Mahlkonig tool, that then mounts a spindle for the gauge.


I'm a bit surprised that everyone bashed old chamber of EK43 that had alignment issues and Titus came up with a tool for it, yet we take all the other high end manufacturers (Weber, Kafatek, Lagom) word of right tolerances without being able to check it at home. Some of them only mention tight tolerances of manufacturing but no guarantee for alignment.

coffeeOnTheBrain (original poster)
Posts: 632
Joined: 5 years ago

#6: Post by coffeeOnTheBrain (original poster) »

ei8htohms wrote:Not understanding what the test you're proposing (measuring from lock to chirp) would demonstrate or how it would be diagnostic. Please do share more info.
Assuming both burrs are perfectly aligned and that there are no tolerance at all burr lock and first chirp would be a micrometer.
Knowing that there are tolerances the distance is bigger.
Assuming one of the two burrs is not perfectly aligned the distance is even bigger.
Hence, one can measure the quality of the alignment with this approach. The closer chirp and burr lock are, the better the alignment.
The EK43 is the only grinder I am aware of for which numbers are know, but if a couple of people would measure this for the Sculptor we would have a values to compare to.

Ben Z.
Posts: 431
Joined: 17 years ago

#7: Post by Ben Z. »

How does this tell you where to shim?

Knowing that you're not co-planar, and even by how much, is pretty much useless.

PPapa
Posts: 188
Joined: 6 years ago

#8: Post by PPapa »

Ben Z. wrote:How does this tell you where to shim?
Heard of Monte Carlo simulation? :lol:

coffeeOnTheBrain (original poster)
Posts: 632
Joined: 5 years ago

#9: Post by coffeeOnTheBrain (original poster) »

malling wrote:While you can get a rough estimate of a grinder being poorly or good aligned between those points, I don't know how your going about figuring out where the misalignment on the carrier is found without measuring or do the rather unreliable marker test
There is no magic trick I am aware of. I see the benefit in having a definitive value rather than "clean wipe" not knowing with how much force the burrs were pressed against each other.
It is possible to consistently identify first chirp. The issue is that burr lock can't be found that consistently, due to the spring in vertical mounted burrs. When burr lock is reached the spring is already compressed so it is hard to tell when the burrs actually touch. One could however check visually when removing the hopper.

coffeeOnTheBrain (original poster)
Posts: 632
Joined: 5 years ago

#10: Post by coffeeOnTheBrain (original poster) »

Ben Z. wrote:How does this tell you where to shim?

Knowing that you're not co-planar, and even by how much, is pretty much useless.
Doing this 6 times to decide which position both burrs should be mounted is quicker and more reliable than doing the marker test 6 times.
After shimming a fair share of grinders I don't prefer to not do it anymore, therefore I prefer this method.