Dishwasher Wheel

Dishwasher Wheel
Posted by on June 30, 2014
Posted in: built projects, creative community, imaging, tips and tricks

This month, I teamed up with Bhaskar Athmanathan for a 3D printing experiment. Our goal was to replace a broken dishwasher wheel by creating a replica based on photographs and measurements.

Measurement notes.

Measurement notes.
Measurement notes.

Measurement notes.
Measurement notes.

Measurement notes.

According to Forbes Magazine, the demand for 3D printing is expected to rise 20% every year until 2017. In my opinion, the omni-presence of 3D printing is a bit sensational (3D printed clothes on site), however it does seem to be the perfect solution for things like small replacement plastic parts. There are already 14 dishwasher wheels uploaded to MakerBot’s free object library, Thingiverse, a plain indication of the consumer need to perform mundane maintenance.

Even more interesting to me is that consumer access to prototyping disperses the responsibility for good design to the end user. Because anyone can have a great idea, this allows for much needed cross-pollination between the manufacturer and consumer, effectively bypassing the commercial designer. Take for example, the fresh perspective of two high school students who solved the watery ketchup problem by designing a new ketchup bottle cap.

Notice that the part is printed to have a shell filled with meandering material.

Notice the print striations create structural vulnerabilities: places where the part might crack or bend.

The wheel was a simpler geometry because it was extruded along one axis.

Soaking the ABS part in acetone gives it a smooth finish. Acetone can also be used to fuse several parts together.

A corn based plastic (PLA) is laid around the ABS part to support the part.

PLA can later be dissolved away with sodium hydroxide or another lye based solution.

Now let’s take a look at our dishwasher wheel. In the first image you can see the difference between the smooth quality of an injection molded piece, and the ABS plastic of the 3D print, which is built up in layers made up of a meandering plastic extrusion. Heating the plastic as this extrusion is laid down bonds it to the layer below. This is done either onto a heated plate, in the case of lower cost printers, or in a heated chamber, found in higher end printers. The last step in this process is to finish the part by soaking it in acetone.

Imagine the weight of the dishes that this small part has to support.

You can see that the metal rod is actually made to fit inside the clip!

How will this material respond to the hot water inside the dishwasher?

Success! The wheel fit and withstood the hot temperatures within the dishwasher. The clip however would not be able to hold a 20 lb dish rack. While modeling take note of the axes of the extrusion (see animation below), this should be a clue to whether the layering of the 3d print could be optimal for the entire piece. In my case, it probably would have worked better to print the three elements of the clip separately and then glue them together with acetone.

Special thanks to Bhaskar Athmanathan of Crowd Compass who did all the 3D production and came up with the idea for this project! For more on this topic, check out this CNN article.

About Yelena

Yelena Prusakova is an illustrator at Fat Pencil Studio.