Exercise dumbbell head prosthetic
Challenge instructions


Ayúdame3D is developing a new type of prosthesis with interchangeable heads that allow for engaging in sports activities:

→ Dumbbell exercises

Holding a dumbbell requires:

  1. A sturdy head that can support weight (between 1 and 5kg).
  2. A head that can open and close quickly to switch between different dumbbells.
  3. ESSENTIAL: A head that won't open or release the dumbbell while the exercise is being performed: → This could lead to serious injuries.

Forearm of a sports prosthesis developed by Ayúdame3D:

Current status

Ayúdame3D is using a metal clamp that attaches to the forearm using an M10 screw and allows gripping the dumbbell handle.


  • It cannot be manufactured using our 3D printers.
  • The system for opening and closing the clamp is secure but slow. → It disrupts the exercise rhythm when switching from one dumbbell to another.

To open and close the head, you have to screw and unscrew the butterfly nut along the entire M8 screw (red arrow):

What do we need?

  • A design for a robust head that can withstand forces of up to 8-10kg.
  • Secure but quick-release closure that can be manipulated with one hand.
  • A design that can be manufactured using FDM 3D printers.
  • A head that can be attached to a prosthesis but can be removed for interchangeability (e.g., for performing a different type of exercise).


The winners of this non-for-profit challenge will earn 2,000 karma points and one custom-made trophy by us:

8 months ago
8 months ago
7 months ago
Due date
6 months ago
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