After performing teardowns on multiple consumer electronics products, I set my sights on a common household appliance - the Nutri-Bullet. The Nutri-bullet is a blending appliance with a simple on/off functionality that is activated when the user pushes down on the blending vessel. Three tabs that are equally spaced around the lid of the blender vessel interface to three spring loaded plastic parts which activate the blender during a push.

I gain access to the internals of the blender by removing the bottom cover of the appliance, which comes off with 4 screws. The bottom cover is actually two parts that are screwed together: a black exterior component made of ABS plastic and an inner grey part that is polypropylene.

The grey polypropylene funnel shaped part is used to direct air flow through the appliance. It allows cool air to flow in through vents in the blender base, then guides the air up along the outside of the blender body before it flows over the motor, cooling it, and is then pushed out through vents in the centre of the blender base. Plastic separating ribs on the bottom help keep the cool/warm airflow separate. The grey part also helps shields some of the electrical components from the moving fan blades, ensuring they don’t come in contact if the blender is jostled.

An interesting feature of the black blender bottom part is the textured finish which is molded onto the sides of the plastic ABS blender bottom. The finish looks like a decorative faux leather pattern, however this area of the part is actually inside the appliance and is not visible when assembled.

The black base is designed with a single small tab (shown top of image right) that aligns to a slot in the blender body just above the power cable (shown image left). This addition aligns the two components together and ensures it can only be assembled in one orientation.

Next I remove the small white plastic tab (shown image left), which secures the wiring in place.

With the white plastic cable tab removed, I unscrew three additional screws and separate the blender body into an additional two parts: a black ABS base (the internal side is shown in grey 2nd from the left, image below) and a black metal sheath that covers the blender body.

The metal sheath is a decorative component that has been deep drawn from a non-magnetic steel, probably a 300 series stainless steel.

The ABS base show below in grey, is actually the black part of the base with the “Magic Bullet” logo on it. This part fits over the black metal sheath, holding it in place on the blender assembly.

Continuing on, I became a bit stuck trying to remove the grey plastic motor casing that covers the motor assembly and other internals. I eventually found an additional 3 screws hiding under rubber bushings within the blender cavity.

With these three screws removed, the polypropylene motor casing slides off revealing a motor assembly that is covered in….pancake batter?

I was expecting some traces of food inside the appliance, but this is waaay more than I anticipated. On further investigation, I found that there is a small drainage hole inside the blender vessel cavity wear the blender vessel sits (two images up in the bottom left corner) that is meant to allow spilled liquids to flow through a pathway in the blender and out the bottom, avoiding all electronic components. However, this design is clearly not functioning as intended.

Circled in the image below is the exit to the drainage hole in the blender cavity. This should align to another channel that guides the liquid out of the blender, however we can see there is a significant amount of food around the part.

The liquid SHOULD flow from the drainage hole into a channel that is molded into the grey motor casing, this channel then aligns with another channel in the black ABS base, this then aligns to a hole in the blender bottom cover where it should then theoretically flow out. The design relies on small holes in 4 separate parts aligning and also for the liquid draining out to not clog these holes. It seems that pancake batter was spilled into the blender cavity, it then flowed through the drainage hole but didnt continue flowing through the channel in the grey blender case. Instead the liquid stayed in the motor/electronics area, covering all of these components in batter. I have to wonder if a better strategy would be to make the blender cavity as seamless as possible to allow spills to be poured out and washed with a rag, rather than relying on a drainage hole.

Looking at the internals of the appliance, we can now see how the blender works. The three tabs on the blender vessel push on the white plastic parts that run along the outside of the black (polycarbonate) blender cavity. These white plastic parts are spring loaded and have a small tab at the end which activates a green microswitch. There are actually only two microswitches despite there being three white spring loaded parts. This is done to provide a points of surface contact for the vessel when pushing down on it. As an added benefit, if one of the three plastic tabs breaks off, the blender vessel will still work in two of three orientations!

Power from the mains goes directly into the two microswitches which are connected in series. When each of these are activated the power then flows to a thermal cut off zip tied to the motor coils. There are actually two thermal fuses, one on either side of the universal motor. These will cut power if the temperature of the coils reaches a certain temperature.

The internals are remarkably simple and features very few electrical components.

The microswitches used can be found on AliBaba for just 16 cents per piece! This would likely be reduced even further for larger bulk orders. The thermal fuses also cost very little.