Cleaning the burrs of a Macap M4 Stepless Grinder

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Dan H.

Postby Dan H. » Sep 03, 2006, 5:42 pm

I'm new to the world of espresso making and managed to gunk up the burrs in my brand new Stepless Macap M4 the first time I used it. (Well, almost the first time. I found out the hard way that what they say about changing grind settings only when the unit is on is true, but that's such an unnatural act....) Can anyone point me to some information that shows how to disassemble this thing so that I can clean the burrs and get back in business? I also have heard that after cleaning the burrs need to be lubricated and would like instruction on that as well. I found one site on the web that had an exploded view of the Macap Stepped version, but it wasn't labeled very well, didn't show any of the attach hardware and looked like it was drawn by a 5 year old with a very dull crayon. I'll post some photos under a new thread of the procedure if I can figure out how to get into this thing without damaging anything else. Someone at HB suggested I look at the information posted in the EG FAQs for cleaning the Mazzer which I intend to do, but if anyone has any Macap specific information or advice, I'd really like to hear it.

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HB
Admin

Postby HB » Sep 04, 2006, 10:25 am

Dan H. wrote:Can anyone point me to some information that shows how to disassemble this thing so that I can clean the burrs and get back in business?


The thread Cleaning a Mazzer Mini offers an outline of the steps. I no longer have a Macap stepless to photograph, but I've copied the Mazzer cleaning instructions below with updates based on my recollection:

Before you begin:
  • Empty the hopper, run the grinder until the chamber is empty. Set the hopper aside.
  • Important: Unplug the grinder. Don't just turn it off at the switch, unplug it.
Disassembly:
  • Remove the safety limiter slotted screw from the side of the burr carrier (it also holds the hopper secure).
  • Stuff a paper towel in the throat of the grinder (in case you drop one of the screws). Remove the three small Phillips screws holding on the black plastic "beauty ring", i.e., the cover with the teeth that engage the worm gear. Lift off the black plastic geared ring. With the removal of the safety limiter screw and the black plastic ring, the upper burr carrier should turn freely.
  • Mark the burr carrier with the grinder's "start here for espresso" setting using a felt tip pen. This will save coffee and time redialing in the grinder after reassembly.
  • Turn the burr carrier clockwise to remove (it's reverse threaded). The threading is very long, keep turning! Mark the carrier at the point the threads disengage with a felt-tip pen for later reference.
  • Clean the burrs with the implements of your choice. I use a small stiff bristle brush, vacuum cleaner, toothpicks, chopsticks, and for the really teenie cracks, a sewing needle. Apply no oils or introduce water into the grinding chamber, and obviously no chemicals of any sort.
Reassembly:
  • Place the upper burr carrier in position. The mark noting the disengagement point should be an inch or so prior to the start of the thread (i.e., the dot on the carrier should be to the right of the engagement point).
  • Rotate the upper burr carrier clockwise (remember, it's reverse threaded, this is in the looser direction). The thread of the carrier should nicely drop into the thread of the lower assembly. Continue turning just a little further, then reverse to engage the first thread.
  • Continue rotating the upper burr carrier until the burrs touch, then back off to your "start here" point marked earlier (it should be backed off approximately 1/8th to 1/4th turn from where the burrs touched).
  • Remember to put back the safety limiter screw.
  • Note: The threads engage easily. If you feel resistance, rotate the upper burr carrier clockwise to remove and try again. Take your time, cross-threading would be a costly mistake!
Please feel free to correct the above. If you would take photographs of these steps, I can tidy up this thread for reference in the FAQ. :-)

Dan H. wrote:I also have heard that after cleaning the burrs need to be lubricated and would like instruction on that as well.


The burrs need no lubrication; what little they do need would come from the coffee's oils. I would not introduce anything into the grinding chamber. If the burr assembly sticks when turning, assure the threads are clean and then apply a teenie bit of food safe lubricant to them (e.g., Petro Gel).
Dan Kehn

Dan H.

Postby Dan H. » Sep 04, 2006, 4:44 pm

Dan, thanks for the information. I looked at the Mazzer information and it is similar to the Macap but, in my opinion, the Macap is much simpler. (I managed to figure out how do to this on my own and with the limited information that 1st-Line sent down to me.) There are no tension springs to deal with in the Macap. When you rotate the worm gear thumbscrews you are moving the upper burr toward and away from the spinning lower burr by means of a very fine thread on the upper burr. The very fine thread allows for very fine adjustments. So here's the drill if anyone else ever needs to do this:

1. Remove the bean hopper.

2. Remove the three tiny phillips head screws that hold the black plastic hopper gear (the one with the useless numbers on it) to the upper burr assembly and lift that plastic gear off. As you face the front of the grinder, you lift the front edge of the gear up and pull it back out of the worm gear teeth. Very easy to do and you can leave the worm drive in place on the grinder.

3. Once that gear is removed, you simply unscrew the upper burr assembly that the gear was attached to. This is very similar to the Mazzer and you turn it clockwise to remove it. It's a very fine thread and silky smooth.

4. Once the threaded upper burr assembly is out you can easily clean it with a toothpick, paper clip or some other sharp pointy object, but take care not to get grounds in the fine threads on the outside of this piece (more on this later).

5. The inner burr is fixed to the motor drive shaft down in the throat of the grinder. I used the same implements to clean that one, again taking care not to get coffee on the inside threads in the throat (a little trickier) and then I vacuumed the throat out.

6. The information I received from 1st-Line said to clean the threads of any coffee grounds on both the upper burr and the threads in the throat with a cue tip dipped in olive oil. You don't need a lot of oil, and I sort of rotated the cue tips while moving them back and forth parallel to the threads. Work a small section at a time and work all the way around. I went through about a dozen cue tips to clean both threaded surfaces. The 1st-Line information was also emphatic about not getting any oil on the burrs just as you mentioned in your response to me.

7. Once all cleaned up, you simply set the upper burr assembly, thread side down, on top of the throat of the grinder and gently, without applying any downward pressure, rotate it in the clockwise direction (the direction to loosen) until you feel the first thread drop into the upper thread in the throat. Make sure it's straight up and down and you can jiggle it a little as you gently rotate it until you feel it engage. Once engaged, and without applying any downward force, slowly start to turn the upper burr counterclockwise (tightening direction) until it freely threads into the unit. Once it starts in you'll get the same silky feel that you had coming out. If it feels like it's binding up, even the slightest bit, back it out and start over. If it doesn't feel silky smooth, back it out and check for grinds on the threaded surfaces again.

8. I threaded the upper burr in until it touched the lower burr, you can tell by feel but if you want to get a more accurate location you can rotate the the shaft that sticks up from the lower burr while gently turning the upper burr until you just feel the burrs touching one another. This is the zero position (burrs touching).

9. Once you have the zero position, you can put the black plastic gear back on. Angle it in from the front of the grinder so that the teeth on the gear engage the worm gear teeth taking care that the three holes in the gear line up with the threaded holes in the upper burr. I had to wiggle the gear around a little to get it to seat on the upper burr surface, but it wasn't hard to do. You shouldn't have to force this on.

10. Since there are three screws holding this gear on you can position the gear in three different positions. I selected one that allowed one of the numbers on the gear to align directly on center of one of the larger screws that are on the top of the grinder housing outside the upper burr gear (I assume these screws hold the motor in the housing). In my case the number 9 aligned with the screw on the lower right corner of the housing. I now know exactly where my zero is and no housing marks were required!

11. From zero I opened up the grind the 2-1/2 numbers that everyone says is the sweet spot for espresso (or roughly 1/8 of a full turn of the black plastic hopper gear, this is a clockwise rotation of the gear) using the thumb screws.

12. Replace the bean hopper and you're ready to go.

That's all it took. It probably took me 30 minutes to do the above, and I had a lot of scraping to do on both burrs. In my case, the 2-1/2 setting from zero was too coarse for my Elektra Micro Casa-a-Leva machine, but a few more fine tunes (this time while the grinder was running) and I was back in business. I may post some photos of this later on, but I think the process was so easy that these written instructions will probably suffice.

Dan H.

mariowar

Postby mariowar » Jan 11, 2010, 3:43 pm

From now on make sure you do not grind finer when the grinder is not working, just try a cup of minute rice. It works like charm !!!

genovese

Postby genovese » Nov 15, 2010, 10:07 pm

I'm a little dubious about putting oil of any kind on grinder adjustment threads, because oil is such a dust magnet, but if both the male and female threads are clean and they still don't turn freely, maybe oiling is the lesser evil. What I would emphatically avoid is vegetable oils, virtually all of which contain some unsaturated fatty acids which will oxidize over weeks and months, darkening and thickening into a hard-to-remove gum. I'd suggest pure mineral oil (also used as a laxative, skin emollient, and lubricant on sharpening stones and kitchen equipment), which is stable indefinitely.

SallyT

Postby SallyT » Nov 20, 2010, 1:53 am

I followed the steps ourtlined by Dan H and repeated it 5 times but I can't get the grind fine enough for the espresso machine. Texture is more for plunger coffee. I have turned the gear 4 numbers to the finer grind but I am still getting the same grind.

In relation to point no.11, I turned the plastic hopper gear from number 7 to 8.1 (roughly about 1/8th of the a full turn).

Once assembled I noticed three threads on the upper past of the upper burr exposed. I cannot remember if it was this high before but the threads look cleaner than the rest at the bottom.

Can someone tell me where I have gone wrong and how get a finer grind?

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JohnB.

Postby JohnB. » Nov 20, 2010, 10:20 am

Did you zero the burrs with the grinder running & hear the ticking sound?

New M4 owners might find this mod I posted on CG several years ago useful. Once done you can easily remove the entire upper burr/adjuster ring/hopper assy as one with no screw removal required.
http://www.coffeegeek.com/forums/espres...ers/349880
LMWDP 267

SallyT

Postby SallyT » Nov 20, 2010, 10:18 pm

No John, I zeroed the burrs with the power off, no sound as a result.

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JohnB.

Postby JohnB. » Nov 20, 2010, 10:44 pm

My guess is that you really didn't hit your zero point the first time. Remove any beans you have added, turn on the grinder & keep adjusting finer until you hear the ticking sound of the burrs touching that indicates you have reached the zero point. Back off slightly until the ticking stops, turn off the grinder, mark the zero point for future reference & adjust to the espresso range.
LMWDP 267

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cannonfodder
Team HB

Postby cannonfodder » Nov 24, 2010, 10:54 am

The carrier threads on all espresso grinders are very fine. Before you put the carrier back into the body, the threads need to be clean of any coffee residue/powder. They need to be clean and shiny, no coffee speckles. The least bit of residue in the threads will bind up the carrier as you screw it in. That is probably what happened to you. It feels like it hit zero but in fact, it is simply stuck from coffee powder in the threads. Use a vegetable brush or even a tooth brush to clean out the threads on the grinder and the carrier before you put it back together. Then it should easily screw down to the zero point. Worst case, you cross threaded the carrier when you put it back together and you now have a door stop.
Dave Stephens