Stiff grind adjustment - grease the threads?

[hbuchtel]

Over here Dan (HB) wrote that when adjusting the grind- "It takes a firm two-handed grip, but otherwise it's easy to switch back and forth."

I just got a new grinder with the same basic design as the Super Jolly, and the grind adjustment is really stiff- I need to use two hands and get that "jump-jump-jump" feeling of metal on metal. Do y'all think it would be ok to put some (high-temp, food-safe, silicone) grease on the threads on the adjustment collar?

I'm a bit worried that putting on the grease would make it too slick and it would move during grinding. I'm also wondering if it will loosen up by itself after a couple weeks/months of usage...

These two threads (Mazzer Mini and Macap) seem to indicate that some grinders come greased from the factory, using some sort of white (lithium?) lubricant... thoughts?

Thanks, Henry

[HB]

I just got a [Laranzato HC-600] with the same basic design as the Super Jolly, and the grind adjustment is really stiff- I need to use two hands and get that "jump-jump-jump" feeling of metal on metal. Do y'all think it would be ok to put some (high-temp, food-safe, silicone) grease on the threads on the adjustment collar?

Is it in fact the same "floating" upper burr design? Below is a picture of the Mazzer Mini; three springs provide constant pressure against the collar to eliminate thread slop:


From Mazzer Mini Component Photos

I haven't seen this design on other grinders and assumed Mazzer had a patent. Macap, Cimbali, and Rancilio are examples of grinders with much longer threaded chambers than the Mazzers and no spring tensioners. I assume your Laranzato is similar. Would you post a photo of the grind chamber to confirm?

Back to your question, there's certainly no harm in applying a tiny amount of lubricant to the threads. If an adjustment is stiff, I wipe some lubricant into the threads with a paper towel. The Mazzers come from the factory with white grease where the adjustment collar meets the free floating upper burr assembly. I have not closely inspected a brand new grinder to check for lubricant on the threads themselves. If there is any, it's a very light coating.

[hbuchtel]

Yep! Very similar if not the same.


with two days worth of grinds

Strange, huh? The only apparent difference is that Mazzer did a better job of painting the thing. And that Al Ruscelli is a better photographer then I am

You know, it is possible that the manufacturer licensed the design from Mazzer... or something like that. It does say on their website "Built on foreign knowledge, manufactured in China." Anybody good at looking up patents?

I found there is a bit of grease in the same place that you mentioned, where the adjustment collar meets the floating upper burr carrier. I put a tiny bit more grease on the lower threads of the collar and put it back together, and ... didn't notice any difference . If it doesn't loosen up with time I'll put some more on next time I have it apart.

Henry

[ira]

It looks like there is paint in the threads which might be the problem. A bit of very fine abrasive on the threads and a few turns in and out with the springs removed might help a lot. Toothpaste or an auto paint swirl mark remover might do the trick.

Ira

[keepitsimple]

The Mazzer mini certainly has a fair amount of grease in the threads. In fact, it can be a bit of a problem when you unscrew the burrs to clean them out. Stray grounds tend to stick in the threads, and you need to get them out. The mazzer thread tolerances do seem to be fairly tight, and stray grounds can stop the adjustment collar moving as smoothly as it otherwise does.

Provided the thread cutting tolerances and finishing on this mazzer copy are as good as the mazzers, I'd have thought grease would be a good idea. You can always remove it if it causes a problem.

Lubricant should make things move more smoothly. They shouldn't - given this design - make them loose. A jerky metal on metal type of movement isn't what you want.

[orwa]

It wasn't until now that I saw this (given that I wanted in the other thread to see the insides)... It's indeed similar, I mean, it cannot be more similar, as in the quote that "life cannot get any better", though not necessarily with the same implications, since some tiny differences may be a source of concern, namely the sort of wear I sort of see on the upper part of the thread (the inner thread on the body of the machine)... Did you notice some powder, or filings on your hands after finishing the cleaning party?

[orwa]

It looks like there is paint in the threads which might be the problem. A bit of very fine abrasive on the threads and a few turns in and out with the springs removed might help a lot. Toothpaste or an auto paint swirl mark remover might do the trick.

Ira

Yeah, this might be it. If the problem was really due to the thickness of the paint layer making the thread tolerances tighter than needed, which would result in a stiff adjustment, and some solid paint powder coming off when you screw/and unscrew the thing, then the best solution may be to apply an appropriate thinner on the inner thread to remove the paint layer (chemicals do a cleaner job in this case than abrasives, no?).

EDIT: The painting of the inner thread may have been done on purpose by the manufacturer as a mean of lubrication. However it doesn't seem to be working well.

[Randy G.]

1- Clean the threads with acetone or lacquer thinner to remove all traces of paint on burr carrier as well as grinder's body (DO NOT drip on outer surface paint!) (lacquer thinner will remove powder coating).

2- Wipe clean and dry with lint-free cloth.

3- Before reinstalling, put a small amount of lube on the burr carrier's threads. If you have some food-grade grease that would be best. Otherwise, a SMALL amount of white grease should be fine. Apply to bottom 1/4" of threads. Keep lube off bottom of carrier. As the carrier threads in it will distribute the grease to most of the threads. Applying it in this way will keep it from getting onto the bottom of the carrier and thus will keep it out of the coffee.

4- From the looks of things, this is not a precision grinder as indicate by the uneven wear of the paint. If you find that there is play in the upper burr after this you will need to use about two turns of teflon tape on the upper burr carrier. This probably will not be necessary as the springs should take up any play.

There was a small amount of grease on the threads of my Kony when it arrived. For metal-to-metal contact, particularly under stress as is being applied by the springs, some form of lubrication is required, otherwise the threads will surely wear and gall over time.

[orwa]

I'll just ignore the fact that this was my idea,, I mean it could be the English man's idea, or my idea, but certainly not your idea. That is to say, it isn't like he was going to lubricate the burrs without you telling him that it's the thread that needs lubrication,, or was he?

[hbuchtel]

Thanks for all the input guys! I'll take it apart again later today and decide what to do. I like the idea of removing all the paint from the inside threads.

4- From the looks of things, this is not a precision grinder as indicate by the uneven wear of the paint.

From looking closer at the pics I took last night, it seems that the 'uneven wear' is in fact 'uneven painting,' a lesser sin

It'll be a sunny day today so I'll take some better pics of the internals.

Henry