CoG: Improved Tool Head Design

Upgraded tool head design for my 3D printer: CoG.

- Improved cooling: Changed from single 5015 blower to dual 4010 blowers.

- Higher flow rate: Changed from V6 hotend to Rapido 2 HF.

- Bearings: Changed from Igus Drylin to LM8UU ball bearings.

- Fewer wires: Added O2 Tool Board for v2 Orbiter extruder.

- Added NeoPixel Mini Button LED's: 3 behind logo and 2 for nozzle.

Notes:

- Still using the BLTouch. If this gets any traction, I will look at adding a more modern sensor.

- Changed to a "wedge" design for the belt clamp. Works too good and can be hard to remove.

- Started using Heat Set Brass Inserts instead of nuts.

- LED's are hot glued into place.

- Hotend fan is 3010.

Have fun! Steve