I have a newly acquired Mazzer Super Jolly that simply will not adjust. The motor runs, the burrs spin, but the collar won't budge. There was a screw fixing the collar to the machine body (for shipping purposes, I assume); I removed that, but it still will not adjust. I hope I'm missing something really simple - I'd rather look foolish than have to repair/replace something. Any ideas?

Could be that the oil and residue build up have glued the thing shut?

I'd try setting the thing in the sun for a few hours, and then trying again once all the metal is warm to the touch.

And post some pics of the crew that you're speaking of.

If it just won't budge, and you've exhausted all other options, put the collar in a vise. I was in the same spot as you this week. I tried a heat gun, blow torch, huge pipe wrench, strap wrench, mallet, and even penetrating oil (even though that's a no-no). Finally, I took off the doser, turned it upside down, gripped the collar in a vise, and twisted as hard as I could. I put the pipe wrench in the spot where the doser attaches and used it as a lever. It took a good 200 pounds of pressure to break it loose!

Afterwards, I chased the threads with a wire brush attachment on a dremel and a chasing file. The threads on these are surprisingly fragile! Be careful. Contrary to some opinions here, I've had good luck using a razor blade, pin, or similar tool to clean the threads without damaging anything. Look for cross-threading, broken or folded-over threads. That's what did it on this grinder; someone carelessly took it apart, knocked the threads on something, then forced it back into position.

Consider covering your vise jaws with rubber to keep from damaging the collar. At this point, a few scratches might be the least of your worries though!

The burr carrier threads are very fragile and bind up very easy with gunk. When I would take the burrs out, I would brush the threads with an old tooth brush or nylon gun brush to get them clean. It only takes a little coffee dust to bind them up.

Remember, lefthand threads...

Ben Z. wrote:Remember, lefthand threads...

! +1

Get thee to the local Harbor Freight (et.al.) and get a large strap wrench. It will give leverage to turn the carrier without damaging it. Also get some liquid wrench or similar. Lay the grinder on its side and dribble it between the carrier and the body. Let it sit for an hour or two. Turn the grinder over and repeat. Then try to loosen the collar. As stated above, when looking down at the grinder, to remove the carrier turn it CLOCKWISE! A second strap wrench around the grinder's body might help.

As Dan (HB) linked, heat works best, hair dryer or heat gun. This softens the dried/hardened oils. Be patient when heating. A strap wrench or similar helps once heated well. After removal the key is to clean deep in the threads as this is where the binding generally occurs. I use a tooth pick or something non-metallic with a sharp point. Keep dry when done. I don't recommend any lube after cleaning. With time if it starts to get a little stiff again just give it another deep cleaning. It's mostly from sitting for a long time and being really crapped up that this happens.

Heat MAY work if the problem is old, dry oils and such that can be partially "liquified" by the heat. The problem is that the collar is inside the threaded body and heat will expand it making a (theoretically) tighter fit.

data point: My Mazzer came with those threads lubricated. A thin judiciously applied coat of what appeared to be (or similar in appearance to) white lithium. Dry threads subjected to the force that the springs exert is, IMO, not a good thing.

If things seem like they are going to hock in a hen biscuit, low heat for an extended period of time until the threaded body gets good and warm, then cold applied to the inside of the carrier to shrink it a bit may work. Maybe use canned air "Dust Off" held upside down if actual cooling spray is not available. Stuff some sort of insulation down the throat so the heat isn't conducted to the motor as a precaution. A PID controlled heat gun would seem appropriate.

I have this stuck-adjustment-ring problem with a La San Marco Grinder SM-90. There is a knob that one depresses to allow the ring to turn. While I am trying to free up the stuck threads, should I be concerned that the knob may not be working and I could damage it by trying to turn against it?