Bike Blender Using a Real Pitcher

The best way to understand the full potential of a bicycle-powered blender and identify the pitfalls of our particular model is to build a blender using  The first step in creating a blender using a “real” pitcher is to obtain a full blender and remove the motor, leaving you with a pitcher and base support.  The motor is the only piece that will not be used, because the blender will be human powered!  However, because the motor is removed, it will be necessary to build something that transfers the rotational energy from the wheel to the blade.  To complicate things slightly, the pitcher rests approximately 5 ½ inches above the top of the axle, so whatever is used to transfer the rotational energy must be 5 ½ inches tall. 

a commercially purchased blender.

It was very helpful to look at existing bicycle blender designs that use pre-made blenders to figure out how to go about building our blender.  There were a few options for how to get the energy from the top of the axle to the base of the pitcher, and the design that was ultimately built incorporates elements from different designs. 

A basic support made from wood blocks stacked on top of each other was the simplest and most logical way to fill the inside of the base and support/protect the more fragile elements.  Inside the top of the base there was room for a block of wood with dimensions approximately 2” X 3”.  The particular wood that was used had a height of ½ an inch; a stack of six blocks produced a three-inch platform that could be used in conjunction with the pre-constructed wooden donut to fully support the base of the pitcher.  Similar to the existing home-made pitcher, a plastic rod and ball bearing were used to transmit the rotation of the axle to the blade.  A hole slightly larger than the diameter of the rod was drilled through the wood platform, and then a larger opening was chiseled out at either end.  One side of the wood platform holds the ball bearing, so the hole needs to be just wide enough to have the ball bearing sit snugly, and should be as deep as half of the height of the bearing.  The bearing will be closest to the top of the rod and the pitcher, so, naturally, the other end of the wood plank will be close to the bottom of the plastic rod, the end of the rod with the piece of the nail inserted through it.  Thus, the hole chiseled into this end of the wood must have a diameter large enough to allow the rod and nail to rotate freely.  After the holes have been constructed the only steps left in assembling the wood block is gluing the bearing to the wood, (using wood glue or other appropriate adhesive) shaping the top of the rod so it will fit into the square opening in the base of the pitcher, and properly inserting the rod through the plank and bearing.

Wooden platform with a hole through the center for the plastic rod

Top of the wood block with the bearing and rod inserted

Full wood platform inserted into the bottom of the base.  A larger hole has been chiseled out so the plastic rod fits properly in the top of the axle. 

  

To finalize the blender, the wood platform must be secured to the base in the right location so the plastic rod reaches both the top of the axle and the base of the pitcher.  To secure the wood platform to the plastic base, small holes were drilled through the plastic and wood and a screw was screwed through both the plastic and wood to hold the two pieces together at the correct height.  The construction of the bicycle-powered blender using an actual pitcher is finished, all that needs to be done before blending is placing the pitcher on the base and placing the base on the rear rack above the axle in the correct orientation. 

Two screws hold the wooden block at the correct height

Fully assembled bicycle blender using a real pitcher

Blindly trying to properly fit the plastic rod into the top of the axle is almost a matter of luck, it takes a few tries before getting it right, and can be easily nudged out of place. Thus, it is necessary to construct a base support that helps guide the base onto the axle properly.  Getting the base on the rear rack takes a few tries, but is fairly secure once the rod is in place.  A basic structural support will allow the base to be guided onto the rear rack and ensure that it is held in place during blending.  The support will be constructed from two pieces of angle iron, one secured against one side of the base and the other fastened to the back of the base.  A screw will protrude from the iron and fit into a slot in the pitcher.  There will be a hole in the side of the pitcher and a slot in the back, as you place the pitcher the hole, it will simultaneously slide into the slot; thus, the pitcher will not be able to move from side to side or up and down.  

Prototype of angle iron base supports

prototype of securing mechanism