Today I decided to add the electrical tape sweeping mod to my K10 WBC. After checking out Teme's blog post, I unscrewed the dose adjuster and removed all the parts in the upper section. At this point, I noticed the ratcheting mechanism was no longer working, but assumed the upper parts had to be assembled for it to operate.

One thing was particularly interested in doing was removing the part indicated in this photo, which Teme says he removed:



I reassembled the doser with this part removed, and discovered the ratcheting mechanism was still not working. At this point I assumed I'd broken something and decided to disassemble the lower portion of the doser to check. I removed the plastic cover and spring, and had a good look, but the ratcheting mechanism is not visible properly without further disassembly, so I am unclear about what it catches on.

I reassembled the bottom mechanism, slotting the return spring into the plastic cover and doser arm hole:





I then completely reassembled the upper mechanism as it was originally, with the part I removed replaced, and the return spring ratchet works fine now. With the cover part removed it doesn't work. I assume there is some friction required that is no longer present without this part, but I still have no idea how the ratchet actually operates. How was Teme able to remove the cover and have the doser work properly?

I have removed that part on my K10 as well. I don't recall having any issues with the ratcheting when I did it. It's working fine like this for me. I can help investigate once I get home.

I'm having a hard time figuring out how the ratchet mechanism works and where the pawl is located. I don't have a screwdriver short enough to remove the bottom screw without opening the grinder and removing the portafilter fork.

As far as I can tell, the only thing stopping the dosing vanes from returning with the doser arm is the friction from the cover piece. With it installed, I can see it moving from side to side slightly as I dose, and with it gone the ratchet gear moves around with the vanes. The only way it works is with the cover in place, or if I put pressure on the dosing mechanism from above to stop it from swinging back round with the arm.

Any ideas?

On my grinder, the top of the cover piece is not swept cleanly and is difficult to brush. Also, I dislike being unable to see how much coffee is about to be dispensed when I am topping up a dose.

I took the top nut off my grinder tonight, but not the c-clip(lazy). Sometimes the vanes will follow the lever back a cm or two, but for the most part the ratcheting works fine on mine with the plate removed. I have to push the vanes back to thwart the mechanism. Maybe some lubrication on the drag area would keep the pin from spinning backwards with the lever. Note I have not lubricated mine. Removing the plate is not really a big deal, but it's convenient for sweeping out the chute area.

This one puzzles me. I did the tape mod and removed the top plate, and I've never had any problem with the vanes going in reverse (i.e., following the handle back after I release it.)

I should point out, though, that I have the adjustment nut screwed down to the next-to-tightest position. Maybe that provides the requisite friction. I single-dose, so I don't care about the amount dispensed with each stroke. I figured having the adjustment nut as tight as possible would aid in sweeping the doser clean.

The only problem I had was when I refreshed the tape several months later. After reassembly, the handle would frequently fail to catch the ratchet on the forward stroke. But that was solved by taking the doser apart again and retightening everything.

The comment about the short screwdriver leads me to make a small suggestion: remove the doser from the grinder instead of trying to disassemble it in place. It's easy to do and makes it much easier to disassemble/reassemble all the parts.

To remove the doser, unscrew the two torx screws in the black plastic chute, and remove the chute (I'm assuming you've already removed the finger guard.) You can then lift the clear plastic cylinder off the doser base. Next, remove the two large torx screws beneath the doser. Then simply lift the doser base up to remove it from the body of the grinder.

With the doser base in your hand, it's a lot easier to see how all the parts fit together.