In a large mixing bowl, combine the sugar, milk, cream, vanilla extract and lemon juice. Whisk until mixed through.
Pour the mixture into the canister, insert the dasher, and secure the lid tightly.
Place the canister into the center of the bucket. Assemble the motor over the canister with the dasher shaft inserted into the hole in the bottom of the motor.
Turn the motor counter clockwise to lock the motor onto the bucket. Place the bucket into the sink.
Plug in the power cord. Allow the mixture to churn for a couple minutes before adding ice to the bucket.
Unplug the motor. Add about 2 inches of ice to the bottom of the bucket and sprinkle on about a ½ cup of the rock salt. Repeat the layers until the bucket is completely full.
Plug the motor back in and allow the ice cream to churn for 20-40 minutes, or until the machine slows or stops on it's own. Keep an eye on it and add more ice as needed.
Remove the canister. If you wish to mix in items such as fresh berries, chocolate, nuts, etc, do so now with a long-handled rubber spatula.
Replace the lid, insert the storage plug, and put the canister into the freezer for 1-2 hours before serving.