Elektra Nino Grinder - Burr Carrier Sticking

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
cdrake39

Postby cdrake39 » May 02, 2019, 4:54 pm

Hi everyone,

I recently purchased an Elektra Nino grinder. It seems to be fairly lightly used and is in great condition. However, I noticed that the upper burr carrier has been very difficult to adjust. There is some definite resistance when turning it and it looks as though the previous owner may have overdid it and wore down the worm gear used for adjustment (I'll be replacing this part). But back to the upper burr carrier, when I removed it by hand I noticed metal filings at the base of the threads. Even after cleaning it with a toothbrush, more metal filings buildup again when it is re-threaded into the collar. I couldn't see any signs of cross threading or damaged threads. Any recommendations would be greatly appreciated, thanks in advance.
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zubinpatrick

Postby zubinpatrick » May 02, 2019, 9:17 pm

Clean both threads very well, I find rubbing alcohol does a great job. Coffee oils can really jam up the threads, and you can't necessarily see them, so clean and then clean some more, you may be surprised. Those large diameter fine threads have natural resistance anyhow, so any microscopic detritus will jam them up.

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civ

Postby civ » May 02, 2019, 9:46 pm

Hello:
zubinpatrick wrote:Clean both threads ...
... rubbing alcohol does a great job.

+1
Do use the toothbrush.

zubinpatrick wrote:... large diameter fine threads ...

Yes.

There's also a thing that happens, a physical phenomenon (cannot recall what it is called) that makes same metal threads seize (very firmly) under certain conditions.

I experienced such a thing with the modified upper carrier I had made for my Cimbali Junior Max.
It scared me crapless to think that all that work (ie: $$$) had gone down the drain, with the threads irreparably crossed.

I called the lathe guy at the shop and all was patiently explained to me along with instructions on how to loosen the parts.
From then on, the upper carrier threads always carry a turn or two of the thinnest teflon tape I can find.
It is replaced every time I take it off for cleaning.

Cheers,

CIV

cdrake39

Postby cdrake39 » May 03, 2019, 10:39 am

Thanks for the pointers! I'll give it a good cleaning today and see how that goes. Would you recommend adding some food safe lubricant to the threads once they're clean? Or would that just act as a magnet for more debris to get trapped in there?

For what it's worth, I removed the 4 springs under the carrier last night and there was significantly less resistance when threading the carrier on.

Freddy Camacho

Postby Freddy Camacho » May 03, 2019, 10:36 pm

Very timely post. I had the exact same problem with my mazzer mini. I had it powder coated and had a few rose gold plated.

When it came back, the upper burr carrier would not screw back. It can only make a maximum of 2 full turn.

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In my case, maybe the process of replating and powder coating causes the threads to seize up.

However, for educational purposes. Can the threads seize up if stored seperately for a period of time?

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civ

Postby civ » May 04, 2019, 10:05 pm

Hello:
cdrake39 wrote:Thanks ...

You're welcome.

cdrake39 wrote:... recommend adding some food safe lubricant ...

In my opinion, a lubricant will help whatever stick in there, be it coffee dust or metal.
Using fine teflon tape does not have that drawback.

cdrake39 wrote:... removed the 4 springs under the carrier last night and there was significantly less resistance when threading ...

The springs act on a set of plungers that are needed to keep the carrier on axis.
They are separated 90° from each other and push the carrier up evenly.
The resistance you mention is a logical consequence of the plunger's action, that's exactly what they are there for.

Teflon tape will reduce the resistance in the threads significantly and also avoid the metal to metal contact that is generating the residue you found.
This has probably happened because threre have been very few full threading/unthreading operations and very little cleaning up since it was purchased.

Eventually, with enough threading/unthreading operations ie: when all the inner/outer thread surfaces mate, there will be no more metal residue.

Bear in mind that in standard use, there are no full threading/unthreading operations to speak of (save for cleaning the grind chamber) as all adjutments you would be making for espresso (once dialled in) will be +/- 10 or 15 degrees max. ie: 1/24th of a full turn.

Don't try to force this process by repeatedly threading/unthreading the upper carrier: it's unneeded and you run the risk of seizure.

Cheers,

CIV

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civ

Postby civ » May 04, 2019, 10:12 pm

Hello:
Freddy Camacho wrote:... upper burr carrier would not screw back. It can only make a maximum of 2 full turn.

I take it that the threads of the upper burr carrier were not powder coated.
Or were they? 8-0!

If not, were they plated?
If so, that's what may be causing the problem.

Freddy Camacho wrote:Can the threads seize up if stored seperately for a period of time?

Sorry but I don't understand your question.

Cheers,

CIV

Freddy Camacho

Postby Freddy Camacho » May 04, 2019, 11:10 pm

Hi CIV.

No, the underside of the upper carrier and rhe threads were un touched. No work done.

I meant, will the thread seize up if i were to dissassemble the grinder for say few months (in store room) before i assemble them back again?

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civ

Postby civ » May 05, 2019, 1:05 am

Hello:
Freddy Camacho wrote:... No, the underside ...
No work done.

Now, that's a relief ... =-)

Freddy Camacho wrote:... will the thread seize up if ...

No.
Why would they?
There's no need to store them separately either.

Thoroughly clean both sets of threads with alcohol and a fine toothbrush, as many times as necessary.
Then reassemble carefully: slowly and without forcing anything, using a turn or two of good quality (thin) teflon tape on the upper carrier threads.

Cheers,

CIV

Freddy Camacho

Postby Freddy Camacho » May 05, 2019, 1:58 am

Reason i asked is...because i have a dissambeled grinder stored about 3 hours drive from home.

With you answer, i do not have to rush there and that grinder assembled.

Thanks for your insights CIV.