Harman Kardon FLY ANC charging dock

Since I often forget to charge my Harman Kardon FLY ANC Headset so that they are, even with the nearly 20h runtime, empty in the least favorable situations and I've long envied the gaming headset with the charging docks. So I've made my own. As you see on my picture, I've tried to use the chargingdock without the additional weight, but it failed, so now I've added a base that can be filled with lead buck shot. 

BOM:

• 1x HK_FLY_ANC_ Chargingtray
• 1x HK_FLY_ANC_ Chargingtray_Base
• 1x HK_FLY_ANC_ Chargingtray_Lid
• 4x 3x15mm screw to secure the base to the chargingdock
• 4x Rubberfeet with OD 15mm
• 4x 3x12+mm screw for the rubberfeet
• 1x Delock Cable USB 2.0 Micro-B Female for Installation > USB 2.0 Micro-B Male 25 cm extension
• 600g+ lead as a weight

Instructions:

Firstly you need to print all the parts, obviously, clean up all the printed parts.

File down the retainingclips on the MicroUSB extension. Glue the male USB plug in place with the help of the headphones but please be careful to not glue the plug to the headphone. Screw the female side in place and curl and if desired glue the excess cable inside the intended cavity. Now it comes to the base, either you use my method with the lead buck shot and the printed base or if you want you can use 120mmx7mmx10mm flatiron, this has nearly the same amount of weight as the lead filled base. The hole spaceing is SideToSide47,5xFrontToBack55mm centered to the middle.

Pros:

• Works
• Cheap
  • ~150g Filament ~5€
  • 1kg Lead ~4€
  • MicroUSB extension ~5€
  • 4 Ruberfeet or feltpads for the printed ones ~ 1,50€
• Looking Good

Cons:

• The insertion is not as smooth as I was hoping for

Changes I perhaps want to make:

• Magnetic MicroUSB adapter for a smoother connection

EDIT 20.01.2022:

Added the final picture with the added base and the printed feet.