Background
The Milwaukee M12 Air Tip Utility Nozzle is a versatile tool designed to use in conjunction with a vacuum to dislodge and remove debris.
As with all things which move, the tool is susceptible to wear and tear. When the brush drive mechanism fails, the tool needs to be repaired to be useful again.
The symptom of a failing brush drive mechanism is a loss of power to the brush: Even though the brush motor was powered on, the bristles were not rotating.
Disassembly and analysis
The Milwaukee M12 Air Tip Nozzle contains a rotating bristle brush which disassembles into a set of constituent components.
These components include:
- The brush bar
- 2 red brush blades
- 2 black brush blades
- The drive shaft to brush bar power transfer adapter
Opening a panel on the side of the Milwaukee Air Tip Nozzle reveals more components:
- The brush drive shaft belt gear
- A belt
- The motor attached belt gear
The drive shaft is chamfered on both sides which allows the brush bar power transfer adapter to be attached to the drive shaft.
The broken part appears appears to have the mounting point rounded off, which prevented the power transfer adapter from properly seating and transferring power to the brush bar.
Continued investigation into the power transfer configuration resulted in identification that this rounding off of the drive shaft connection was persistent on the other side of the drive shaft.
The drive shaft belt gear appeared to have a rounded connection, preventing power transfer.
The solution was clear: Two replacement parts were needed.
Result
After 3D Modeling and printing was complete, the parts are installed into the Milwaukee Air Tip Nozzle.