Compak K10 burr mount installation w/ Teflon

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DanoM
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#1: Post by DanoM »

I've been taking my new K10 apart more times than I should. Basically keep looking into the burr chamber and trying different methods to sweep that cleaner. (I might never be successful, but I still like the grinder!)

Anyway, those of you that have screwed that burr carrier in and out on these things probably know how difficult it is to turn at times. I was resorting to using Loctite on the threads and not torquing down the bolts for the outer burr all the way. Last inspection of the burr mount showed that I had 2 loose bolts, so that old loctite gets trashed and I'm torquing down the bolts.

Next problem is with the bolts tightened I get a tremendous amount of rubbing between the screwed collar and the burr carrier to the point I can see roughed up aluminum on the burr carrier. I cleaned that up and tried Dow 111 that I had on hand, and it was basically no better than without.

On hand I have some paper thin Teflon/PTFE sheets, and I cut out a collar of this that will go between the aluminum burr carrier and the steel threaded collar (bottom side). Torqued down the burr mount bolts and installed this setup.

It turned in far easier than without the teflon ring. Adjustments are still very solid, and could probably hold just fine without the locking screw on the collar. Looks like this will make pulling out the upper burr much easier now.

So maybe this will help someone else that spends too much time unscrewing their K10 collar.

Also if anyone thinks I might be causing problems or doing something wrong with the original collar setup please let me know! I don't want to destroy this beauty!
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JohnB.
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#2: Post by JohnB. »

Are you removing & replacing the upper burr carrier with the top cover attached? If so it shouldn't require much effort.
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angman
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#3: Post by angman »

Also your K10 is pretty much new. Outside of taking it apart and inspecting it out of curiosity and perhaps regular deep cleaning every few months stop taking it apart. You might end up causing more damage than good. Once you put some beans in, the burr chamber will be full of coffee dust once again anyway.

DanoM (original poster)
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#4: Post by DanoM (original poster) »

Once I get an improved sweeper in the chamber I won't need to open it up for a long time. My test sweeper mod reduced the grinds in the chamber from nearly 4g to 1.5g, but the tape holding it on wasn't going to last. Have some other attachment media to look into I guess.

As far as the effort need to turn the collar. When removing it the first time I tore a pair of old gloves from the effort to unscrew the collar. It wasn't easy to turn, but it did turn.
When I put the collar back in the friction against the steel/aluminum parts was strong enough that the aluminum began to wear. I hadn't yet disassembled the collar at that stage.

I cleaned off the worn aluminum particles, and eventually put the thin teflon sheet in there. Now installing is much easier as there's a slippery layer between the 2 metals.
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JohnB.
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#5: Post by JohnB. »

If you leave the top cover attached to the burr carrier you have the leverage of the adjuster handle working in your favor. Without the cover it's a bitch but with it attached mine just spins in & out. Make sure you have some food safe lube on the threads. As far as the two sections grinding against each other that has never been an issue with my K10. I keep the 4 burr carrier bolts tight so that washer/shim is fully compressed & the upper section still turns with no drama.

The sweeper mod is normally done on the doser sweepers, not in the burr chamber. With the chute modded & an acid brush you can reach in & pull out the stray grounds between pulses. My typical retention is .1g -.2g .
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DanoM (original poster)
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#6: Post by DanoM (original poster) »

Doser sweeper mod has been done. Quick and easy. Filed out the chute bevels and sanded that down to 1000grit - very smooth.

For my burr chamber I have a 1-2mm clearance below the sweeper that leaves a layer of coffee packed on the bottom, and I'm no where close to 0.2g of retention. Pulsing, sweeping won't fully clean it out, unfortunately. When I stuck some acetate sheet on one of the sweepers the retention dropped well below 1g, but the double stick tape was only a temporary test and would fail in time.
(Maybe I should just ignore what I can't reach and go with it... I've been happy with the performance so far.)

Thanks for the pointers!
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JohnB.
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#7: Post by JohnB. »

Are you measuring that 1.5g retention after a thorough cleaning of the burr chamber or is that what is held back from each dose? I took a quick look in through the chute opening & I'd say that my sweep assy. is sitting closer to the bottom of the burr chamber then yours. You might want to check that it's fully seated. There are areas in the chamber that will fill in after a cleaning so I expect to see a 1-1.5g loss from the first dose after I've done a burr carrier out cleaning. From that point on retention is only a couple tenths of a gram.
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DanoM (original poster)
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#8: Post by DanoM (original poster) »

Once I re-install the burrs and run coffee through I loose about 3-4g on the first run. That is post chute sweeping and through to chamber center, pulsing and sweeping.

After that my grind in and out becomes quite stable, as one would expect.

I'll likely install a single plastic sweeper to keep the wall and bottom cleaner and be happy with that.
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Bob_McBob
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#9: Post by Bob_McBob »

Can you post a photo of the modification?
Chris

DanoM (original poster)
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#10: Post by DanoM (original poster) »

I will post a photo of the mod once I have one that can be relied upon, if you are talking about the sweeper anyway. My test sweeper consisted of acetate sheet and double stick cellophane tape cut to size and stuck on. Size was from the bottom of the chamber to the bottom of the center burr and an extended flap on the end to clean the wall.

For the teflon ring it's just a ring cut to size, but next time I have this apart I'll take some photos there.
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