I need help from HB members who own Compak K-10PB's as to what is its normal grinding speed. I need this because I suspect I have a lemon and the vendor, CCS, gives the purchaser only 14 days, not 30 days, to return an item bought under Buyers Remorse, and 7 days have passed already. The first day the shipment arrived near my bed time, so that day was lost. Day 2 I spent dialing in a dark roast without anything special happening. Day 3 I hit paydirt. I dialed in a Nicaraguan 3 days from roast where the crema flowed and flowed. In the porcelain 6 oz cup it seemed like 100% crema, reddish brown with tiger stripes. I had only seen this at the local Intelligentsia and in videos. I had never seen this at home over 4 years with a Macap M-4 grinder and a PID Silvia, or more recently in 1 month with the Macap and a Vetrano HX. I was so excited that instead of savoring it as it was I followed routine and added microfoam for a cap, The next shot was identical, and this time i drank it straight. Heaven on earth. Day 4 more of the same.

But doubts had surfaced on day 3. I had timed only one grind for my usual 14-15 grams and the grind took 20 seconds. Didn't Wilco Bos report filling his LM single basket (9 grams) in 3 seconds with his K-10WBC. And John Weiss said, if memory serves, that he ground 18 grams in 5 seconds with his conical Robur. I called CCS repair and spoke with Roger. He called Josh at Compak, who said 20 seconds was too much, and wondered if CCS had cleaned out the demo. Roger did not know. I remembered a post on HB about an 89 cent acid brush in the plumbing dept of Home Depot. Got the brush. It was slim enough that it got all the way in the chute until it hit metal. 5 grams of grinds came out. Maybe the long grind was due to stopped up grinds in the chute. The CCS provided brush had only touched the opening of the chute. Using the new brush to clear the chute and pulsing 2-4 times after grind I used a dark Colombian roast that was fresh, but I didn't like, so I wouldn't mind wasting it on test grinds. and did 9 grinds of 14-15 grams, weighing on a scale before and after the grind. Now the grinds were 10 seconds for 6 grinds, and one grind each for 9, 11 and 13 seconds. Much better, but still too slow.Days 5-7 have continued to mean about 10 seconds for 14-15 grams. I weigh before and after the grind, and if I'm in a hurry to pull a shot, and there's a discrepancy in weight before and after, the missing gram or so is always recovered by additional pulses and clearing of the chute.

Day 4 I called Roger to discuss progress, but he was busy so left a message. Days 5-6 were the weekend. Today called CCS. Roger was busy but I spoke with Tim. He had disassembled and repaired many grinders, but had never timed any grind for any grinder, but felt the results in the cup were what mattered. I told him I would post here and ask for members experiences with grind time on the K-10PB.

Why did I buy the K-10. After reading the threads "Titan Grinder Project" and "Can It Beat The Robur" I decided to buy a large conical grinder due to the promise of more crema and new flavors. On the Compak K-!0 some of the early problem areas seemed to have been addressed by Compak, the fact that HB Team member "another Jim" had bought one in 2007 and still was posting favorably about it, most users seemed enthusiastic about it, and cost was lower than the Robur, all inclined me to choose the K-10.

When the K-10PB appeared recently under "Buyers Remorse" at Chris Coffee for $1250.00, for a savings of $250.00 from list price, I called CCS and spoke with Mary. She explained that the item was not a return from a dissatisfied customer, but actually was a demo used by CCS staff for a show, and it had ground about 5 lbs,, so it seemed to me that it was partly seasoned in,and had been operated by professional staff.

Now I'm not sure I should keep this K-10. Despite the wonderful crema, will the grinder last. The 10 second grind time for 14-15 grams seems to suggest I have a lemon. I'm tempted to pack it up and return it to CCS and fork over another $1400.00 or so for a new Robur.

What would you do. Any comments would be appreciated.

Mine grinds 18g in about 5-6 seconds and I am single dosing, with a hopper full of beans I estimate it will be even faster.

10 seconds seems a lot to me.

Pay the extra 250 and take a new one...

Kfir.

Thanks Kfir for you very valuable information. I suspected the K-10 could be faster, You confirm my view that all is not well. I appreciate your suggestion to just go for a new K-10. Will sleep on it and think it over.

Your time and the whole trouble figuring out whats wrong is worth a lot more than that.

Get a new one and enjoy the experience of a brand new product...

Good luck.

Kfir.

I've summarized the opening post below:

Carpediem wrote:[Bought a lightly used Compak K10 Pro Barista...] Heaven on earth. Day 4 more of the same... However, the 10 second grind time for 14-15 grams seems to suggest I have a lemon. I'm tempted to pack it up and return it to CCS and fork over another $1400.00 or so for a new Robur.

If a few seconds faster is important, then get the Robur, since it's faster than the K10. For home use, I personally prefer the K10 because the Robur is too fast for my usage (I owned the doser model for a few years). I just timed the K10 using the "1 1000, 2 1000, 3 1000" method. It took 5-6 seconds to grind a 15 gram double.

That's faster than your model, but I don't agree this proves your grinder is a lemon. One possible explanation is that the burrs are not broken in. Or the beans you use are harder than most. Or the grind setting is very very fine. But the new burrs are the most likely explanation; Chris Coffee Service may have used it at a show, but they probably didn't break in the burrs enough.

I've tested a lot of grinders and the grinder settings on some are really squirrely out of the box (the thread Do grinder settings change while breaking in? elaborates on this point; IIRC, the K10 was one such grinder). I run 5+ pounds of stale coffee through a grinder like the K10 before testing (30 seconds on, 1 minute off and repeat).

The results, in your words, are "Heaven on earth". Personally, I think you're worrying needlessly. On the other hand, the Mazzer Robur is a better grinder in terms of build quality, if that's your overriding concern.

Carpediem wrote:... mean [grind time] about 10 seconds for 14-15 grams. I weigh before and after the grind..

20 seconds is clearly too long, but 10 seconds is not too bad. When single dosing, it's hard to get an exact grind time because the beans popcorn around. Try grinding with a bean load in the hopper; you might shave a couple of seconds off the time.

I'm with John. If you're single dosing -- with or without the hopper in place -- and not using something to prevent popcorning, it's going to take more time to grind a dose.

So, if you're not using a hopper, go get a jar of any Spice Island peppercorns, dump out the peppercorns, and put the empty bottle on top of the beans you load into the throat of the grinder.

If you're using a hopper, put an inch or more of beans in it.

In either case, particularly with beans in the hopper, you may find the grind setting is too fine (i.e., the shot runs too slow) and you'll need to coarsen the grind.

Now, if you've already taken these steps, then a couple of causes come to mind. As Dan suggested, the burrs probably aren't fully broken in. Mary probably doesn't know exactly how much coffee got ground when the grinder was a demo, and even if it was 5 lbs that's not very much, especially if the beans were dark roasted, as CC's roasts tend to be.

And dark roast could be part of the problem. If really oily beans were ground in the grinder, either by CC or you, residual oils might be responsible for a slightly slower grind time. You could flush the grinder with light-roasted beans or get yourself some Grindz and clean it out thoroughly (and then use lighter roasted beans to clean out the Grindz.)

I should note that your grind time isn't very far from the norm that most of us see with the K10 PB/WBC. Seems to me that the fact it has reduced from 20 seconds to 10 seconds is a good sign that either the burrs are getting seasoned or coffee oils are getting purged, or both.

Another point:bear in mind that many people believe "slower is better" because it heats the beans less (or so the theory goes.)

Finally, assuming the outlet is delivering 110V to the grinder, I'm hard-pressed to think of any mechanical or electronic reason why your grinder would run slower than any other K10 that's been broken in and used properly.

Peppersass wrote: Finally, assuming the outlet is delivering 110V to the grinder, I'm hard-pressed to think of any mechanical or electronic reason why your grinder would run slower than any other K10 that's been broken in and used properly.

I agree that the time doesn't sound all that bad but 110v at the outlet? If that's all you are getting call the electric company as 120v at the outlet & 240v at the box is the norm in the U.S.

Kfir wrote:Mine grinds 18g in about 5-6 seconds and I am single dosing, with a hopper full of beans I estimate it will be even faster.

10 seconds seems a lot to me.

Pay the extra 250 and take a new one...

Kfir.

This sounds about like my experience. Admittedly I don't pay attention as I single dose and am half awake during

I don't really get this obsession with grind speed. If the shots taste great who cares?

NIL,

My K-10PB does 18 grams in 7-8 seconds. I single dose with an OE short hopper using a tamper for the lid.

Anecdotally, by sound, it seems like the bulk of the dose is done in 5 seconds or less, with a few bouncing beans taking the remainder of the time.