I'm a hobbyist. But I walked this thing through its steps. In the last 5 years I have changed 2 more coffee grinders. I do a lot of different things, so I often change circles. Grey-left stone for rough grinding. The one on the right is white and fine and is used to sharpen drill bits, knives, mower blades and other tools with sharp edges. No speed controller with dimmer is used. It has a circuit board under the center of the device. Apparently I would say that this is its own regulator. When I'm sharpening and polishing, the slower speed allows for more control over part of the project. I installed a new DeWalt 8" spoked wheel on the left side and it stayed balanced. No chatting or jumping around. Mine is attached to an HF stand to which I added casters. I didn't lock the wheels and it didn't move. I'm glad I switched to a different coffee grinder. First, it is much heavier than the others. I always make an offer when it fits. In this case. PRIOR TO INSTALLATION, TAPE the underside of the circuit board with tape to prevent metal shavings or particles from getting onto the circuit board. There is also a slot for a fire bowl on the front. Hold or cover the compartment. I have 3M aluminum tape. This is the preferred sealing method, but 2-inch tape will also work.