Week Four

We received one of the three bones printed from the .stl file that we converted last week. We measured the length, and the cross section length of the different parts of the bone (including cross sections at the hip, lower hip, flattened, mid-shaft  lower mid-shaft, above the knee, and the lump).

We then applied the Three Point Bending test to the bone, and figured out the distance between 2 loads to be 0.226 in (8.5 mm)

Since the length of our bone is too small (14.6 mm) comparing to the width of the force applicator, our result might not be accurate. We were advised to scale the dimensions of the bone to 100 mm for the subsequent bones.

Index finger comparison showing the printed model

The printed model on the Three Point Flexural Machine showing that the width of the force applicator is larger than the length of the printed model

The .stl file of our bone is saved as facet feature in Creo; it is not a solid that has definite volume and shape. We are trying to convert the facet feature to a real solid so that we can adjust and modify the geometry of the bones.

Unfortunately, it appears that using a facet feature will prove impossible for the nature of this project. We have tried multiple programs to edit and/or convert the file into a form that can be edited more easily within Creo. Since we have to be able to edit the geometry of the bone, the group is trying a brute force approach to modeling the bone within Creo by creating a series of sketches that match the axial geometry of the bone and then using the swept blend tool to create a 3D model of the bone from the sketches. While this method is extremely labor intensive, we are very confident that it will create a successful, accurate model of the bone.