BPlus Apollo Grinder - initial observations - Page 2

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

Postby Spad_VII » Feb 15, 2019, 5:44 pm

devlin2427 wrote:Sending stuff from Europe to Taiwan is quite costly

That's not manufacturer fault. That's part of customer due diligence when decides to buy an item from an overseas manufacturer. It does not apply on Bplus only. In my case I'm well prepared to face it, just because I can duplicate any part at the toolshop, so who cares. I'm used to restore high end vintage turntable arms down to the needle microbearings, I'm not scared by a hand operated coffee grinder :lol:

devlin2427 wrote: the combination of aluminum and steel can be tricky over time and sustained use.

There is not aluminum rubbing against steel here.
Mixed aluminum-steel assemblies is an engineering problem solved one century ago, more or less. And this is not an aircraft engine having parts working with 800 °C differentials just 20 mm away each other.

devlin2427 wrote:I don't think alignment and tight tolerances were a priority if the burrs are touching outside of the locked position.

I think you read only the even lines of my thread.
The burrs stop rubbing each other at an adjustment that is light years away from espresso range, and doing some approximate reverse math the radial runout should fall around 0.08 mm, give or take.

Searching thru the forums I've spotted people complaining abut burrs rubbing in the working range on other hand grinders, that is an order of magnitude worse than the Apollo does. Given the price tag, to me is enough to qualify the Apollo as a fine instrument. I'm not dumb enough to try to compare this performance to a HG1 or a Stance.

Has your M47 0.00002 mm of radial runout? Ok, good for you, I'll sleep well anyway.
LMWDP #620

devlin2427

Postby devlin2427 » Feb 16, 2019, 8:26 am

I'm not talking about aluminium rubbing against steel but rather that the whole grinding assembly is secured by a couple of screws mounted in aluminium. That could become a problem over time.

Spad_VII

Postby Spad_VII » replying to devlin2427 » Feb 16, 2019, 9:39 am

If I had a dime every time I've ripped a screw thread in aluminum, I'd be billionaire by now.

So, since is wise to learn from own errors, but is way wiser to learn from others, and way cheaper too. Here we go with what I've learnt thru the time:

-When you have no clue about the machinery you are using, read the manual and hope for better.
-When a machinery is going out of service, take it apart completely, and learn about everything worn out and why before disposal.
-When you think to be confident enough about assembly and disassembly, start with a complete relube on new stuff before using it.
-If you think that a particular aluminum assembly needs to be periodically taken apart, it might be a good idea to drill out all the threads and install helicoils, do it before threads start failing, I was into vintage motorcycle racing stuff when young, done countless times. You could not imagine how many times you have to take that old junk apart just to make it run.

Here we come with our damn grinder: the threads you mention are too small so is the side wall, the helicoil is no option. do a lube with MoS2 or anti seizure copper grease, and then think about how tiny is the screw every time is being operated.

The bottom flange has no structural part than ensuring the outer burr ring seats correctly: the flat slots transfer the torque, and the brute force of grinding pushes the ring upwards. so a light tighten is all it needs.

One last thing, the upper screw bolting the crank is machined, not rolled. Being stainless steel at a shiny finish against stainless steel at a shiny finish, it is likely to seize the second time you lock it in.
BPlus deliver this thread dry. I consider this a technical mistake. It should be lubed at the origin with either MoS2 or copper paste.
LMWDP #620