This thing was inspired by these two projects: https://www.thingiverse.com/thing:1027406 and https://www.thingiverse.com/thing:1369340. It should help you use your thumb to better guide your Dremel and offer eye protection.
Update: 8/7/17, v 1.1 & 1.2
Tapered for better compatibility!
Tested on a Dremel 3000, but it should also work with models 285, 4000, and 8000.
Step 1: Find water bottle
Step 2: Measure bottle's thread ("D" on image)
If thread diameter is 25mm, use Option A.
If thread diameter is 27mm, use Option B.
If thread diameter is NOT 25 or 27mm, follow Step 1.
Step 3: Profit
Option A: Generic 7-11 "Select" branded water bottle found at 7-11 convenience stores. Specifically, 1.5L bottle.
Option B: Aquafina 1L water bottle, Dasani 1L
Theory behind each option: Option A has loose parameters and will likely be more compatible with bottles having a 25mm thread diameter and 2.0mm pitch. Meanwhile, Option B has tighter parameters and is optimized for brands Aquafina and Dasani, which are global. Because Option B has a 2.5mm thread pitch found on other bottles, Option B will also fit other 27mm water bottles.
- Currently, water bottle thread sizes vary on manufacturer. I'm really not looking forward to testing different bottles, so please use one of my supported water bottles. I found different water bottles with similar thread diameters, but different pitches! Many bottles don't even have precise 25mm or 27mm measurements: I found some 25mm bottles with tolerances between 25.2 and 24.8, which makes the design process really, really difficult (and hence, my shot gun approach with Option A). For example, Option B will fit both Dasani and Aquafina very nicely, but you will notice a difference between those two brands. Dasani has a thread diameter of 27.3, while Aquafina measures slightly over 27.15. Despite the small .15 difference, you will definitely feel them tighten differently! I know, it sucks, but this thing should screw onto your water bottle as easily and snug as your Dremel!
Ok, so you may be asking yourself, why is this guy going around measuring different bottle thread sizes? As long as the clear plastic part hangs, who cares? This guy's going water bottle crazy with this thing! He must have no life! True, true. I caught myself buying several different water bottles; And to be honest, I have other little projects with water bottles, so I need them for testing.
Anyway, good luck.
PLA (This thing will not print properly with ABS)
Layer height: .2mm (Threads will not print properly with anything greater! please use .2mm)