I recently took the top burr out of a Compak K10 Fresh to clean it (I was also hoping to mod the chute to reduce retention). I replaced the top burr as normal, everything felt fine, no resistance, threads seemed aligned, the burr retention plate screwed back in no problem.

When I turned it on, the grind was extremely coarse (I was getting tree bark), so I tightened the burrs down using the adjustment knob. There was a lot of travel - it took a lot of turns until it wouldn't turn anymore. I then backed it off a few turns. Turned it on, and the motor runs fine - the lower mechanism works.

However, I can't adjust the top burr at all. It is completely locked. It won't loosen or tighten with the adjustment knob. It is completely locked / seized. I asked a coffee tech guy I know to look at it. He has tried to separate the burrs, but despite taking lumps out of the machine and the burr retention plate, is unable to get the mechanism to budge.

At this stage, the grinder is completely useless, and is fit for the bin. I can't get the top burr in or out. This is a disaster. For such an expensive grinder, it seems remarkably fragile. I wonder if a hard bean knocked the grind off when I ran it very coarse?

Has anyone seen something like this before?

If you're going to toss it, then maybe start hacking away at it.

The grinding chamber has a part #. An option is to cut through the grinding chamber below the upper burr carrier, unbolt the lower burr carrier, unbolt the grinding chamber from the motor, and replace the grinding chamber and upper burr carrier.

I just bought $5K worth of Compak grinders and haven't had the opportunity to take them apart yet. But I've worked on other grinders and if I had to guess I'd say either the upper burr housing threads took a nick or got some coffee grounds stuck in between and when you tightened it down it seized up. Try a little heat from a blow dryer and/or a little olive oil. Then carefully work it back and forth until it comes loose.

Thanks for your suggestions.

I think it's too far gone for the olive oil and hairdryer treatment... at this stage I'm looking at an angle grinder to split the top burr and chamber.

I've written to Compak to see if they have any suggestions. Hopefully they'll offer to take it back for repair...

I'm sure you can send it in for repair, but not after you take an angle grinder to it.

I experienced the same problem on the only one I ever took apart to replace the burrs, I had the threads meticulously clean with a light amount of dow 111 for lube. Like yours it threaded easily all the way in until it suddenly just seized up. I am surprised with Compak's lack of knowledge with this problem. Here is another one I believe the OP never found a resolution to.

Cannot Remove Top Burr Carrier - Compak K10 Fresh

Hmmm. Danetrainer's no slouch at this kind of thing. He's an advanced Subaru mechanic. I like his post on the other thread, suggesting how to deal with threads of dissimilar metals where the thread galls.

danetrainer wrote:I experienced the same problem on the only one I ever took apart to replace the burrs, I had the threads meticulously clean with a light amount of dow 111 for lube. Like yours it threaded easily all the way in until it suddenly just seized up. I am surprised with Compak's lack of knowledge with this problem. Here is another one I believe the OP never found a resolution to.

Cannot Remove Top Burr Carrier - Compak K10 Fresh

If it threaded easily, then suddenly seized, it's hard to believe the threads were "meticulously clean". The fact that something got jammed in there is evidence that they likely were not.

It's obvious the tolerances on the upper burr carrier are extremely tight. That's a good thing for grind performance, but it also presents a servicing issue. It seems great care is required to clean the threads completely and also make sure they don't get bumped and damaged while out.

Absolutely they were meticulously clean, my complete surprise with it happening. For what it's worth I've always heard of it happening with the Fresh model. Metallurgy is a very delicate balance for manufacturers with details related to casting, machining, finish, hardness and most of all cost.