Why did I produce a cup holder?
My truck was purchased in 1991 that year and for many years people did not have cup holders. Ford did not care if we had worn the coffee in our laps. My truck was not used for many years up to the time I received it. When I received it, it had only 4,000 miles on the odometer. I put on 22,500 in the last two years. I decided it was cheaper to keep the truck and make a coffee cup holder, than to sell the truck to have a new coffee cup holder.
Design intent of the holder.
Since I went to Starbuck’s most of the time, I pattern the holder to hold a standard Starbuck’s cup.
I wanted the fingers as you see above to be flexible, to grip the cup. I have a truck with very heavy suspension, which when I travel down Interstate 87 toward the TechShop I get bounced around a bit. That’s where these fingers keep the cup there on my dash without flopping to the floorboard.
The ring in the middle of the cup holder gives the holder a lip to hold a band type squeeze grip to the fingers if needed. However, I have not needed it so far.
The fingers give the cup holder royal crown look. But more importantly I wanted to know how much coffee I had toward the bottom of the cup. With fingers I did not have try to see through the plastic.
My dash is made of vinyl and my cup holder is made of ABS plastic. I used double sided tape from Home Depot to stick the cup holder to the dash. I have not had any problems with it separating so far, and I have had it there for several months. At the end, I am happy that TechShop has the equipment to do this type of work. I used the TechShop 3-D printer and their computer to design this part.
Step 1: How To
How I designed the cup holder.
The CAD program I used was SolidWorks student addition, that’s because I was familiar with it. I started out developing three layered planes in parallel from bottom to top. I drew a sketch of a circle on each plane. Then used offset entities to get the thickness of each section. Then I used the loft feature to connect the three circles on each plane. Then I used Boss-Extrude and Cut-Extrude to shape it up then I used the Circle Pattern feature to get all the fingers. The rest was fillets to smooth things out.
I found that I was trying to get the flex for the fingers, without making it too brittle. My first try I made it too thin and it turned out too brittle.
How to get the holder from CAD to CAM was to change the file from a part file to a STL file. The STL file is used to layer the drawing in printable layers for the 3-D printer. I used the MakerBot to produce this part.
Step 2: STL File
Here is my STL file: