how do you use the tamper thing on the kitchenaid k400? the manual is confusing.

You use it to push ingredients down towards the blade while the blender is off.

DIAGNOSIS: Trying to use it incorrectly can be dangerous or damage the lid.

FIX: Here's the safe way, step by step:

1. Press the stop button and make sure the blender is completely off.
2. Remove only the Lid Center Cap from the main lid.
3. Insert the tamper through the opening to stir or press the contents down.
4. Remove the tamper, replace the Lid Center Cap securely, and then you can resume blending.

IF THAT DIDN'T WORK: If ingredients are still not blending, you might be overfilling the jar. The maximum is 56 oz (or 48 oz for the glass jar). Try blending in smaller batches.

HEADS UP: Never, ever remove the jar from the base while the blade is spinning. That can break the coupler.