This simple design provides compact storage and dispensing of small, single-use measuring and mixing cups and jars, as well as a variety of similar containers. Such mixing cups and jars are often used in hobbies for mixing paint colors, or multi-part glue (like epoxy), etc. Coffee pods, Medicine dosage cups and bathroom cups are also options.

Only the base of the rack is 3D printed; using heavy wire for the upper rack arms allows me to make the rack taller than I could make on my printer using one printed part. Wire also reduces filament usage, and greatly shortens print time. I use 12 gauge galvanized wire (available in 50 ft. rolls at hardware stores), but the provided source file easily supports other wire sizes (see Customization section below).

The most useful feature of this design is the ease of customizing the base for your own size cups or containers. The source file is included here, and all dimensions of the base are keyed to one value, the diameter of the largest part of your container. This value can be easily set in one cell of a spreadsheet, built in to the source file. So, you can create a custom-sized base, with the wire holes properly spaced, by just changing one value in the source file (using FreeCAD), as described in the Customization section below. The wire diameter is also set in the same spreadsheet, so you can customize the wire size easily also.

The .STL files included here are only examples of what I've generated from the same source file, by modifying only the "Cup Diameter" field in the source file. The STL file names include the cup diameter (mm). For reference, here are other dimensions of the prints generated by the STL files included:

To bend the upright support wires, see the steps in the image above.

1. Make your first 90 degree bend at the height you want for the number of cups you want in your rack.
2. Measure and mark the top wire bend location, using the "Wire Bend Length" column in the table in the Summary section (see note below). Make your 2nd 90 degree bend that distance from the center of the first leg bend.
   Cut the 2nd leg wire at the same length as the first leg.
3. Finally, bend the short top wire section to approximate the curve of the cup's largest diameter (usually the lip of the cup, or the jar lid).
4. Insert the bent wire upright into two of the holes in the base, as shown in the photos at the top of this page.

Repeat all steps above for the other three wire upright supports.

Note: If you customize the source file spreadsheet to create your own cup size, the file's spreadsheet has a field at the bottom called "Wire Bend Length" - this field is automatically re-calculated when you change the "Wire Diameter" field. Use the value in this "Wire Bend Length" field of the spreadsheet for the top wire length when bending the wire for your customized cup size.

The source FreeCAD file is included, if you want to make a rack for your own specific cup or jar size. Even if you don't know FreeCAD, it is easy to change the key dimensions, since these dimensions are defined in a built-in spreadsheet. Just download FreeCAD from the internet and install the application. Then load the .FCStd file from the download files on this Thingiverse page. In FreeCAD under the "Combo View," double-click the "Spreadsheet" under the "CupRackBase" body on the "Model" tab's tree.

This opens the Spreadsheet tab. The yellow-background values are used in the design dimensions for the base part. You only need to modify the "Cup Diameter" value in the yellow field. Changing this value (as long as it is not too extreme) will adjust all the appropriate dimensions of the base model. Try just making small changes first, then checking the results in the 3D model. You can see your new dimension changes by viewing (double-clicking) the appropriate "...Sketch" objects under the "...Pad" items in the body tree.

If you use wire that is a different diameter than the 12 gauge wire I used, you can also easily change the wire diameter in the "Wire Diameter" yellow field. If your printer is like mine, you may need to make this diameter a bit larger than the actual measured diameter of the wire, to allow for inside hole diameter printing inaccuracies of the print process. I had to increase the diameter by about 0.8mm (from 2.1 to 2.9) for my printer - your results may vary.

Once you've made your dimension change(s), you can generate your .STL file in FreeCAD by clicking on the "Body" heading under "CupRackBase" on the "Model" tab's tree, then selecting "File > Export" from FreeCAD's menu. Save the STL file, then print your customized cup rack base!

Have fun!