3D Printed Drill
The USA alone throws away at least 2M broken cordless drills per year (see market research below, and develop the market research further by contacting sources). A lifetime design, modular, 3D Printed cordless drill is a perfect solution here, and builds upon the current 3D printing craze.
Problem statement - drills, and especially cordless drills, are throwaway devices. They break and you can't fix them readily because they are not appropriate technology. Here we design the world's first appropriate technology cordless drill.
The goal is to select an appropriate Depth of Modularity to make any cordless drill motor, battery, speed trigger, gear set, and Chuck inter-operable with any other.
This converts any drill to one about 10-100 times cheaper (lifetime extends from 1 to 100 years, and cost drops from 100 to about 50 for a professional grade drill - for the initial purchase, so all things considered, the open source version is about 100x cheaper over the lifetime.
- Made of 3 main modules:
- battery interface to connect to any existing battery pack
- battery pack
- Modular Architecture
- Motor, Gearbox, Chuck, Battery pack, Charger, and Trigger can be sourced off-the-shelf
- Open source motor scores higher
- Initial is clutchless, later phase includes clutch
- Professional grade - 18V or higher
- Based on a 3D printed pack for 18650 Cells.
- Pack is stackable in parallel for longer life
- Battery pack can later be turned into a battery belt for other applications, such as 5Ah, 36V for a minimum Electric Bicycle
Later Phases Requirements
- Battery adapters - allow any battery from any other drill to be used so that other used batteries can be reclaimed.
- Modular gearbox means any amount of torque can be generated.
- Different toolheads for different functions
- Battery pack is stackable for longer life or higher voltage interconnection. 3 Ah at 3.7V - 20 of these hold enough mileage for a basic Electric Bicycle
BOM and Parts Extraction
- 57 geardown 18v motor - 
- 735 motor - 18V, 5/44 mm - 
- 755 motor - 24V, 5mm shaft, 42mm wide - 
- 775 motor - 12-36V- 5/42 - 
- 775, 795, 895 - the larger one has lower RPM (12000, 10000, 6000 rpm) - larger has more solid connectors - 
- RS555 - 12-36V - 2000-6000 RPM - but 3 mm or smaller shaft. This appears to work -  - but appears to be too fast.
- 3D printed battery holders - 
- extracting a gear motor from a drill - 
- Making a hub for a cordless drill - 
- Good video of extraction for a robot. There are standard motor sizes that can be used. Clutch consists of ball bearings that are pressed down with a spring which catch on a motor disk. 
- 3D Printed Gears - 
- Standard Motors - 550 size motor.
- Standard gearboxes - Dewalt example - 
- Standard chucks
- Market share report - 
- Harbor Freight recalls 1.7M cordless Drill Master drills -
- The two above imply that there is at least 10M cordless drills sold in the USA every year, assuming the 1M is all that Harbor Freight sold (gross underestimate). That is about a $1B market in the USA alone, or 6B globally.
Lifetime of a Cordless Drill
- 1-2 years in a contractor scenario, check out the guy who spends $5k/year on drill replacements for 40 cordless drills/saws - 
- 4 years, woodworking business - 
Analysis of Industry Standards
- 3D Printed Screwdriver on Hackaday
- Super tiny drill - 
- Stratasys - 
- Taking a DC motor out of a cordless drill -@
- Alibaba cordless drill motors -