DF64 Alignment advice (pictures and video)

Grinders are one of the keys to exceptional espresso. Discuss them here.
soer9459

#1: Post by soer9459 »

Hi there

I've attempted to align my DF64, but have a question about the sound and feel, versus the visual results.

After the alignment I've done, the videos show that there is still a choppy "sound" as well as "feel" when rotating the burrs. But as the pictures show, the marker has been wiped evenly on both the top and bottom burr, indicating a well aligned grinder.

Are the burrs not actually aligned, or is it common for the burrs to continue to feel and sound as if they are out of alignment? If so, why? (Doesn't make any sense in my head)

I've attached two examples from separate tests (alignment not changed between tests).

Test #1
Video: http://www.youtube.com/watch?v=TyCbVK0duqw



Test #2 - Tried to be extra careful for the burrs to just barely touch
Video: http://www.youtube.com/watch?v=CW6MmglwKU0


GDM528

#2: Post by GDM528 »

soer9459 wrote:Are the burrs not actually aligned, or is it common for the burrs to continue to feel and sound as if they are out of alignment? If so, why? (Doesn't make any sense in my head)
I wish my alignment looked that good ;)

The lower burr may not be perfectly centered on the motor's drive spindle (mine isn't) which can still create a cyclic sound as it rotates. Also, the difference between touching and not touching is approximately equal to the radius of the atoms, around 150 picometers.

User avatar
Jeff
Team HB

#3: Post by Jeff »

How thick did you put on the marker?

I've read that if you get it on too thick, it can sort of ball up and wipe itself away.

soer9459 (original poster)

#4: Post by soer9459 (original poster) »

Well, that was unexpected!!

Seems that it worked, since i can now grind finer than ever before!
I just tried grinding for espresso on my old setting, and it ground so fine that the burrs got completely coated in fine powder, to the point where no coffee could get out of the grinder at all! What a massive difference.


I don't think that the marker was put on in a particularly thick layer. I just tried again applying as thin a layer as possible, and got the same result.
Still very confused about the sound though, as it continues to be periodic rather than constant. The same goes for rotating the burr by hand. It still only seems to have resistance about 1/4 of the way round

Giampiero

#5: Post by Giampiero »

Correct...edit, my reply was to the post of Jeff

Nunas
Supporter ♡

#6: Post by Nunas »

That sound is not normal in perfectly aligned burrs, even though they may be aligned better than they were. What alignment method did you use, aluminum foil shims or sanding (perhaps give us the URL if you followed a video). Also, did you do both the top and bottom burrs? However, it's a question of how perfect you want this grinder to be. If you're happy with the results, then you might leave it be. My ZF64W is out by about the same as your DF64, at least according to the sound. I Can't be bothered to shim it any more, as it is working fine. One small comment, perhaps off base, I don't know. I think I see a bit of coffee powder here and there in your photos. When doing an alignment, you should start with a perfectly clean machine, as even a small speck of coffee between the burr and the carrier can throw things way off.

soer9459 (original poster)

#7: Post by soer9459 (original poster) »

I shimmed with aluminum foil.
Bottom burr was perfectly aligned, so I didn't do any adjustment.
The top burr was far out of alignment, and only about 10% of the marker was removed before I started aligning

I made sure that coffee was cleaned from the relevant areas, so it shouldn't make a difference.
I've tested it after these pictures were taken with the chamber and burrs completely cleaned, and got similar results

I've tested it now multiple times again, and the results come back the same. I'm not really sure what to believe, but the grind has improved significantly, so I think I'll just keep it as is for now, and possibly seek further improvement some time when I can be bothered :)

mikelipino

#8: Post by mikelipino »

That sound combined with the nice marker test results seem well-aligned to me. I do the same, test for wipe by carefully adjusting grind setting to only barely hearing a dragging sound. And it will sound "choppy", because at least one point will higher on one or both burrs. This is because of either further micro misalignment (down to the sub-micron) or because the burrs are not manufactured perfectly planar. Neither are cause for concern (and unavoidable with actual, physical systems) so I'd take the near perfect wipe test and excellent espresso as a win!