Leg Design:

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By: Victoria Osaji, Manufacturing and Development Engineer

Table of Contents

Introduction:

The legs are one of the most important and complicated parts of this project. I mean without legs or not being able to control the robot the project would not meet a lot of requirements and it would not work. So we took this very seriously.

Level 2 Subsystem below:

14. 3rd Generation Velociraptor (Th) shall have a leg design that can support the mass at 505.5g at different positions for standing, bent, and crouching.

Design 1:

legdesign1

Figure 1: This design was modeled after the UCI linkages.

These legs were the image in Figure 1. At first I was having trouble designing these legs because I didn’t understand completely how they worked. But as I did more research, I realized the UCI linkages were all about the circular motion Click Here.

 

legmechanism

Figure: The model for design 1.

Understanding that, I found a design to reference online. The reason we did not use these legs is because I was having issues simulating the walking pattern on solidworks, I am not sure if there was too much or too little traction. So I decided to 3D print it just to see if I can fix the issue manually. I think the problems stem from the dimensions and the sizing of the legs. I didn’t have any exact measurement, I just eyeballed it and you cannot do that with these robots because they are very sensitive in that sense.  Fabian, the President of the Wednesday class, tried to improve this design by making his own. The appearance was better when I simulated it on solidworks the walking pattern was inversed. To conclude, we were unable to use this design.

Design 2:

The next design I modeled on solidworks also was the Theo Jensen model.

Design 3:

This design was also modeled after a model I found on youtube, the Stephenson. For this model I printed out screenshots of the legs from online and measured out every part so I could recreate them on solidworks. The legs consisted of different size triangles, 4 links and 1 one oddly shaped piece plus the foot . The holes for all the connections were 3mm. These legs actually moved on solidworks however they were not doing the complete walking motion so I 3D printed them to manually play with them and I noticed the same thing.

 

References:

http://sites.uci.edu/markplecnik/projects/leg_mechanisms/