Over the past two weeks we have created a prototype of our finger rehabilitation device. This included a plate that fits to the palm of a team member’s hand, thumb and pointer finger caps and resistance bars. This model was used as a proof of concept so only two of the five fingers were included. In the final design all five will be included.
The print of the plate had the following settings:
Type: PLA with Natural PVA as support
Part: Palm brace with attachments
Density: 20%
Support: enabled – everywhere – 100% – tower enabled
Build plate temperature: 60 C
Print time: 14 hr 49 min
Quality: Normal quality
-Perfect Print
-File saved as a cura project
The print of the two resistance bars had the following settings:
Type CPE
Part: both resistance bars
Layer height: 0.1mm
Density: 20
Build time: 52 min
– Slight delamination
– Print a skirt or add glue to build platform
The print of the finger caps had the following settings:
Type: TPU with Natural PVA as support
Part: Fingertip attachments
Density: 20%
Support: enabled – everywhere – 100%
Build plate temperature: 70 C
Print time: 2 hr 41 min
Quality: Normal quality
– Perfect Print
The plate and finger caps turned out nearly perfect, they fit the hand well and were of very high quality. The plate fit well, and the material of ABS created a ergonomic and rigid piece, as desired. Velcro was added so the the product can be secured on the hand. Upon evaluation, we have decided that a potential improvement would be to find a way to reduce the amount of material used while maintaining the comfort and rigidity of the piece.
The finger caps fit well and the TPU material worked as expected. For the next print, we want to find a way to make the finger caps have a slightly tighter fit around the ends of the fingers. We also plan to use less material so the print of the finger caps will be quicker.
The resistance bars fit well but were designed to be thin and somewhat rectangular and as a result bend sideways causing the finger caps to rotate and the overall bending process to feel awkward. An update to this design will make them symmetric and bend with the fingers. Also, the snap fit ends of the the resistance bars fit well into both the finger caps and the plate. The TPU material provided our resistance bars with the flexible properties that we were striving for. On the next print, we are going to change the infill density of the bars because the resistance forces that the bars created were not quite as strong as we want them to be.
Finally, since the functional capabilities were all successful to some degree, we will keeping aesthetics in mind while redesigning all the parts for the next prototype. We will smooth out sharp edges and give it a cleaner look overall.
Photos of currently assembly:
