This is a cup holder for the Evelo Aurora electric bike. I wanted something I can attach to the stem. I needed to be able to adjust the angle, and allows a foam/paper cup to be removable.
The outer part of the stem on the Aurora is a little over 30mm diameter. I've designed the bracket to work with 30-35mm stems.
- 2x M3 30mm bolts for middle bracket.
- 2x M3 12mm bolts for stem bracket (longer bolts can be used).
- 4x M3 nuts
Various Brands ABS
You will need supports for the middle bracket. I printed this with 50% triangular infill, 0.15mm height, 3 perimeter shells.
Assemble adjustable middle bracket to facing bracket
Use 2x M3 30mm bolts and nuts to attach the adjustable middle bracket to the part of the stem bracket that faces the rider. Top bolt goes through the bracket. Bottom bolt goes under the bracket and is used to add additional tension. I found it easier to install the bottom bolt first, loosely. Do not over-tighten else the bracket will crack. Just tighten enough to provide extra tension. See also levelling below.
Assemble to bike shaft
Fasten front-facing bracket to the rider-facing bracket using 2x M3 bolts - size of bolt depends on actual size of shaft and how much you want to fiddle with the installation 12mm bolts worked well for me.
Use ring with cup
The ring I 3D printed works with the Dixie cup shown, and others. Other size rings can be printed - let me know if you need a larger/smaller ring, and I'll add additional files. The intent is to push the ring firm onto the cup, and place the ring into the bracket loosely. File down parts if needed. This should be a loose but sufficient fit.
Note that if you create your own cup holder, the tab is 21.5mm x 7.5mm (fitting into a 22mm x 8mm hole). The left, right and front sides slope inwards at 10° for 12mm height. The back side is flat. The flat back gives enough support for the cup to not fall out. The sloped front and sides makes it easier to take the drink on and off of the bracket.
Note that when riding, the beverage will slosh around. Don't fill the cup too full.
The middle bracket is designed to be adjustable for leveling. Place water in a paper cup that is in the cup ring, and place on bike. Level bike, and adjust the bracket until water is approximately level.