10 Sept 2018

Motorised dual finger prototype changes from a screw driven actuator to a winding actuator for experimentation. Design uses the same drivers and motor style from previous design but with different performance characteristics. Using a winding system, the fingers offers greater gripping and lifting strength, but at the cost of degraded holding strength. In different use case scenarios, greater gripping strength may be more beneficial in one case, and greater holding strength in another case. As performance requirements vary from different scenarios, it would be difficult to have an ideal solution. For the case of the style of motors used, an ideal solution would be to have a good balance between gripping and holding strength. Another factor to consider is the overall space the motors take up for a given performance. Using a screw system along with long actuation lengths results in a large motor form factor which greatly takes up the limited space in the hand. As such, a winding system would be beneficial in saving space.  To create a balance between gripping and holding strength for a winding system, a worm based motor with according pitch could be used, however, there's lack of small sized worm motors available for a low cost.

Features
- Similar features to previous design
- High gripping strength
- Smaller form factor

Specs
- Winding based actuation
- Same motor driver design

Further Work
- Better end stop design
- General design improvements, e.g. better reliability, smaller size, etc.