Dishwasher Dial - Clean/Dirty Indicator

We recently got a new dishwasher appliance and the old 3D printed clean/dirty indicator that I made years ago ( 1"x4") no longer fits the new washer's geometry. This model is my new design in the form factor of a 3 inch square.

Project Requirements:

1. Clear indication of Clean/Dirty
2. 3" x 3" footprint
3. Less than ½" thick
4. Internal retention between clean/dirty status
   • Shall retain status when washer door is opened and closed
   • Shall not restrict the motion of switching status

Design Summary:

The square footprint does not lend itself to a linear slide for changing status, as my old indicator had, I decided to go with rotating dial for the status indication. Since a round wheel inside a square leaves unused space in the corners, it made sense to add a magnet on one of these corners for status retention. 

I designed the parts to work with parts that I had on hand already:

• R188 bearing (¼" ID x ½" OD x 3/16" thick)
• 4x5mm and 4x2mm neodymium magnets

The overall device comes out to 11mm thick, so it is under my ½" req.

The bearing mounted wheel is designed to be full thickness to give it a little mass. When you turn the dial, you can give it a nice little fling and it will spin for a while before settling in one of the magnetically constrained positions. This gives you a little rush of roulette-style gambling while waiting to see if it lands on the status you wanted :)

Print Details:

The dial wheel is designed to use simple filament change to get a different color for each status indicator. I am printing these parts at 0.15mm layer height, so the CLEAN text is 0.3mm tall and the DIRTY is 0.6mm tall.

• When you print the wheel, the first color change will be to the CLEAN text and the second color change will be for the DIRTY text.

As always, I am including STEP and Native Solidworks files for your convenience. The Solidworks parts 

There is a test file that prints just the four features that interact with the bearing and magnets. This should take less than 30min to print and if things don't fit well, you can modify the STEP or Solidworks files to optimize for your printer.

*No supports needed for any parts

Assembly Notes:

• Glue magnets into the wheel and lid.
  • Two 4x2mm magnets go in the wheel
  • One 4x5mm magnet goes in the lid
  • Pay attention to polarity, obviously
  • The forces are pretty low here, so cyanoacrylate glue will do just fine - no need to mix up epoxy
• Push bearing fully into wheel and then press wheel and bearing into the lid. 
  • I made the clearance between the status lettering and the lid pretty close, so you might need to pull the wheel back slightly after inserting to get the clearance just right. If you do that, just put a drop of CA glue on the shaft in the center of the bearing - I made the shaft short so there is no chance of this glue getting to the ball bearings.
• Glue base to lid
  • There is a step in the lip of the lid so that you should be able to add small dots of glue and not see any on the outside after mating the parts.
• Affix to the washing machine with whatever process you like.