Superfly Extruder - A Compact BMG Conversion

# Superfly Extruder
## A Compact BMG Conversion

**Update (28th Sep 2021) - A user reported an interference between the tensioner and the plastic gear when used with flexible filaments. This was an error in the design, so it is now corrected. The high-tension version is also removed as the new one should cover all use cases.*

The Superfly is a compact extruder designed to reuse the excellent dual drive gears of the beloved BMG extruder. As with the BMG, the Superfly is a dual-drive geared extruder with a 3:1 gear ratio. It is designed with the following characteristics in mind:

- compact and lightweight
- short filament path
- balanced center of gravity
- easy to source hardware
- support both NEMA 17 and round NEMA 14 motors
- easy to print

Please see the project [GitHub Page](https://github.com/mustcode/superfly) for more detailed information on the Superfly including additional assembly instructions and images

### Parts
You will need the following parts of your BMG:
- the **drive shaft** with the large plastic gear attached
- the **drive gear**, this is the gear that is on the drive shaft
- the **idler gear**, its shaft, and the two needle bearings inside, these are the parts that were on the BMG's tension arm
- **2 x MR85 bearings** that the drive shaft runs on
- **Thumbscrew** and **spring** (the washer is optional)
- The **motor gear**, if you're planning on using a motor without a gear pre-installed

In addition to the BMG parts, you will…