This instructable will detail another method to modify your Cuisinart SupremeGrind for espresso. This is an alternative method to the one provided by 'sehrgut' entitled 'Hacking the Cuisineart SupremeGrind for Espresso'. I highly recommend reading that instructable as this one will be only supplementary.
Firstly, I'd like to say that while this method will allow the machine to create a finer grind, in the process, we will remove the safety systems that protect the grinder from damaging itself. Modifying the grinder in this way can damage your grinder and will likely void the warranty (if there is one). After completing this modification, be well aware of the distance between the burrs before you start grinding.
My current opinion is that the even after completing this procedure, this grinder is not capable of producing a good espresso grind. However, it will produce a grind much finer than what it is natively capable of.
This method uses two step approach. In the first step we remove the physical barrier preventing the hopper to turn past the finest grind level. In the second step, we disable the electronic control that stops the grinder from turning on when the bean hopper is turned past the finest grind level.
Step 1: Cut the Plastic Tabs
First, we need to remove the plastic tabs that stop the hopper from turning past the finest grind setting. Empty the beans from the hopper, unscrew the hopper, and separate it from the rest of the machine. You'll see two protruding plastic tabs on the top of the machine that are separated by the circumferential groove. Removing these tabs will allow the hopper to turn past the furthest grind level. I used a pair of wire cutters which worked well. These pictures show these tabs already removed, but hopefully you can see where they used to be.
Step 2: Open Up the Machine - Pt. 1
The Cuisinart Supreme Grind uses two electronic safety switches to disable the grinder. The first is activated by inserting grind chamber (the clear plastic container that holds the ground coffee). By pulling out the grind chamber, you disable the switch and disable the grinder (ie. it won't turn on). Reinsert the grind chamber, and the machine will start right up. The second electronic safety switch disables the grinder when the hopper is turned past the finest grind setting. We have to disable this switch to get a finer grind.
To open the machine, the first step is to flip the grinder over and unscrew the four screws on the bottom of the machine. These are hidden by the four rubber feet in each corner. Remove each rubber foot, then use a phillips head screwdriver to unscrew each screw. Remove the bottom, being careful of the power cord. The third image is the machine flipped upside down with the bottom cover removed. You'll see some electronics on the bottom of the picture, and the grinder motor is in the center of the machine. We don't have to deal with either of these.
Step 3: Open Up the Machine - Pt. 2
Next, we need to remove the top cover of the machine. Do this by unscrewing the four screws in the corners of the bottom of the now overturned machine. You'll need a long phillips head screwdriver to remove these. There is also one screw above the grind chamber (see second picture). When you remove the top cover, be careful of the electronics as they restrict the movement of the top cover.
Step 4: Open Up the Machine - Pt. 3
These pictures show the top cover removed. You can see the circuit board (green) for the timer switch on the right. The next step is to remove the circular part under the top cover held down by four screws.
The second picture shows the circular cover removed. You'll see several springs; one of them (see image) is part of the second electronic safety switch.
Step 5: Disable the Electronic Safety Switch
The first picture shows a close up of the switch and the switch activator. This is also what the switch should look like when finished with this step. In the second picture, you'll see the switch activator and the spring mentioned in the previous page. I'll be using the term switch housing to refer to the area which the switch activator can be pushed into.
When the hopper is in one of the defined grind settings, a large semicircular plastic tab on the hopper which fits into the the circumferential groove pushes the switch activator into the switch housing allowing the grinder to turn on. When the hopper is turned past the finest grind setting, the tab no longer pushes the switch activator into the switch housing, allowing the spring to force the switch activator out of the switch housing and disabling the grinder.
Since the machine can be turned on only when the switch activator is inside the switch housing, the solution is to always have the switch activator in the switch housing.
Removing the spring and glue the switch activator into the switch housing (see the first picture).
Step 6: Put the Machine Back Together and Enjoy!
After glue dries, put the machine back together.
Your machine should now be able to grind much finer than originally! Again I stress that care is required to make sure that the burrs do not touch. All of the built in safety mechanisms that normally stop the burrs from grinding against each other have been removed. The instructable "Hacking the Cuisinart SupremeGrind for Espresso" gives good instruction on how to check the distance between the burrs.
To to make the grind finer, turn the hopper past the finest grind setting and turn the machine on.