Pharos alignment, inner bolts - Page 7

Grinders are one of the keys to exceptional espresso. Discuss them here.
OldNuc
Posts: 2973
Joined: 10 years ago

#61: Post by OldNuc »

Part of the stability issue is to remove the outer plastic bolt covers and re-insert the outer bolt and lightly tighten, finger tight. Now align and lock the inner burr bolts, nut driver tight. Now measure the inner distance between the plates with the outer bolts loose at the 3 outer bolts. Machine the outer bolt covers to ~0.001" to 0.002" greater than your measurement.

You can buy 5/8 OD X 3/8 ID brass tube from Online Metals and 3/8 od X 5/16 id bushings from McMaster-Carr. This saves drilling 5/8 rod straight and the bushings will hold the brass covers centered on the outer bolts.

Outer bolts with metal covers 15ft-lb torque or so.

That should make it stable.

Nate42
Posts: 1211
Joined: 11 years ago

#62: Post by Nate42 »

beer&mathematics wrote:Not true. I can move the burr around by pushing it with the inner bolts locked down as much as I can. After grinding the TW coffee, the settings have changed drastically by about 1/4 turn. I'll need to re-align it and possibly keep the Pharos away from the TW coffee.
If you can move the outer burr by pushing it, its not locked down. Are you sure your bolts aren't stripped or something? I used to have the kinds of issues you're describing before I modded mine, but nothing since, and I've done some seriously hard beans. I'm not familiar with TW coffee, what is it?

I will say that mine is slightly different from yours because I am only partially voodoo'd. My inner burr axle still goes clear through to the bottom plate, and I still use the funnel. I don't bother with the plastic ring that goes over the funnel though, I have the funnel exposed, which is nice because I can tap it directly to encourage grinds to come out.

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Nate42
Posts: 1211
Joined: 11 years ago

#63: Post by Nate42 »

Oh yeah, and one more thing that I've seen. If you grind REALLY hard beans, I've had my handle turn on me, because I actually applied more torque grinding than I used to tighten the jam nut on the handle. This can make your zero appear to move (because your handle is your only absolute reference point) but doesn't actually impact burr alignment. The remedy is simple - put the handle on tighter.

A quick check I like to do to verify burr alignment is to hold the grinder up by the handle, letting gravity pull the burrs together to zero. Then I slowly rotate the body (holding the handle still) 360 degrees. While doing this, keep an eye on the gap between the adjustment nut and the bearing. If you have an alignment issue large enough to worry about, there will be an obvious up and down motion in the gap as you rotate. Note that if you have coffee particles trapped in the burrs you may need to give it a few spins to clear them out before it stays flat.

Anyway, if you find your zero has moved, but my check shows the alignment is still good, chances are the only thing that actually happened is the handle turned.

ciaodown
Posts: 22
Joined: 10 years ago

#64: Post by ciaodown »

Great pics, thanks!

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beer&mathematics
Posts: 1366
Joined: 11 years ago

#65: Post by beer&mathematics »

Nate42 wrote:If you can move the outer burr by pushing it, its not locked down. Are you sure your bolts aren't stripped or something?
I haven't thought of this, but it's certainly a possibility. I've been too busy to take a serious look at the grinder so it will have to wait a few weeks until I can look into this more.
Nate42 wrote:Oh yeah, and one more thing that I've seen. If you grind REALLY hard beans, I've had my handle turn on me...
I haven't thought of this either, but this makes a lot of sense and is probably what happened. Sorta shocking really since I've tried to loosen the handle before and wasn't able to after months of self-tightening.

Ps TW = Tim Wendlebow (Norwegian coffee roaster and ex-barista champ iirc).
LMWDP #431

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