3d printing project

Title

Abstract (10%)             Mary

Introduction (10%)

Theory (10%)

Procedure (10%)   Jeff

Results (20%)

Discussion (20%)   Aziz

Conclusion (10%)

References (5%)    Everyone

Appendix (5%)        Ali

 

I have some data collected that I will distribute in this email. Everyone will just input their references as they use them into the proper section.

 

Mary, a lot of your section will need information from the papers I sent you all a while ago. We were investigating how can we reduce the cost and weight of the Model 5x Hosmer Hook, while maintaining the universal attachment to the wrist unit, the design efficiency of the model, and the gripping force as much as possible. By being able to 3D print efficient prosthetics, Prosthetist and patients can print out there own models at home or in the office for less. The Model 5x Hosmer Hook costs between $420 - $585 ( Link to Website ), while printing it in ABS material could cost less than $20 in material. We found that about 5 pounds of force is needed to hold a small object within the grasp of the original hosmer hook. So, this is why we did a FEA of the 3D CAD model - to test the deformation of the model when 5 pounds of force is exerted on the inside of the hook and to see how can we minimize the max displacement, stress, and strain on the 3D model when truss are added. We are hypothesized that if 3D printing and truss systems are used on our reverse engineered model, then the new model will be able to withstand the amount of force needed to grasp small objects and still cost less than the original model. The Equation of Deflection [Deflection = (Force*Length)/(Area of Moment of cross section*Youngs Modulus)] and The Second Moment of Area for Torsion [Angular Deflection = (Torque*Length)/(Shear Modulus*Torsional Constant)] were looked at when designing.

 

Jeff, the Model 5x Hosmer Hook was scanned on a Solutionix C500 3D Scanner, Surfaced on Geomagic Wrap, Reversed Engineered in Geomagic Design X, and the FEA was done on Solidworks. We 3D printed in ABS material. The model had to fit a M12-1.25 screw size for the universal wrist unit. 10% material infill on the 3D printed parts. In the FEA, 5 pounds of force was put on the left side and the right side, individually, of two models . One model that is a close replica of the original, and another model with the first iteration of truss being added. The results (displacement, strain, and stress) will be in the pictures attached to this email. Ttruss decreased the max displacement of about 5mm in the left side of the hook and in the right hook. More work in the future will be done to optimize the truss system to lower displacement, as well as max strain and max stress.

 

Aziz will simply discuss the results and conclude everything, bringing it back to the hypothesis. Discuss that other 3D printed material will be looked at, like Nylon and PLA, more evaluation on a better truss system will be tested. Human testing on amputees and non-amputees will be added in future results to analyze efficiency and to compare to FEA (I added a picture of an attacher mount that I created for future testing on people without amputations). Discuss how our project differs from other projects out there.