Aluminum 3 Axes Corner

jmak
Entry ID #: 7643
Created: Sun, Jan 12, 2020 8:17 AM

We noticed that there were fewer gusset pieces that provided strong support while being able to fit into small places. We promote more compact designs in all our builds and having a piece that provided good support without occupying much space seemed essential. We used a 1 hole x 1 hole aluminum piece (cut from a 1 x 1 x 35 aluminum bar) for the function of a small support, but the part still could bend with moderate amounts of force. Therefore, we decided to add a 3rd axis to the part to add much more structural integrity since all 3 axes would be supported, and the 1 x 1 x 1 piece would be functional as a support.

The 3 main characteristics of this part are its small size, strength, and 3-axis functionality. When mounting a tower using this piece, one can place a c-channel perpendicular to the chassis bars, and use two 1 x 1 x 1 aluminum piece on each side to support it. As seen in the picture attached, a 1.5” screw can be passed through the screw it into the chassis bar with 0.875” worth of spacers to enhance the support provided by the piece, since the chassis bar cannot bend either. By adding the 1 x 1 x 1 support piece on both sides, the force on each piece is halved, almost ensuring that the 3 axis piece will not bend unless subjected to relatively extreme amounts of force that are very unlikely to occur in a VEX match. Also, the Z-axis hole also provides another hole for serving various purposes, and can also serve as a 1 hole extension to the 2 wide C-Channel bar. When mounting taller towers, however, there is a need for additional support bars at higher points since the higher torque amounts can lead to slight tilts that affect the tower’s functionality. This support provides a good amount of support at the mounting point, and when complemented by another support at a higher point, the 1 x 1 x 1 piece can help create a rigid tower mounting.

Like the CAD I do for my team’s robot, I used Autodesk Inventor Professional 2020 to create the part. I began by first drawing out the dimensions of a C-channel provided by the VEX website. Once drawn out, I created a 0.546’’ by 0.546’’ square then extruded the square by 0.046 (width of aluminum c-channels). 2 0.046’’ by 0.546’’ rectangles were then sketched onto the extruded square. These rectangles overlapped each other and were positioned at the edges of the square. The rectangles were extruded to a height of 0.5’’. I then used the fillet tool to recreate the smooth edges found on VEX pieces. I used the existing radii measurements provided by VEX cad. To create the holes, I found the position of the closest corner by adding/subtracting 0.081 from the initial position. After positioning the point, I created a 0.182” by 0.182” square. This was repeated on the two other sides. The fillet tool was used again to smooth the edges of the 0.182’’ squares. After analyzing the pieces, I found that I had to shorten the piece’s outer edges by 0.124’’ to account for the overlap in metal.

I learned that having the dimensions written down and the piece drawn out made the production of the piece more efficient. I was introduced to 3D designing in my freshman year, but I rarely used 3D designing until Tower Takeover where I was approached to do CAD for my team. I have enjoyed watching the prototypes I made in CAD be materialized into working components on our robot. After realizing the efficiency of 3D design, I will definitely use 3D design software in the future. Because of the simulations and animations provided by Inventor, I was able to demonstrate how a DR4B worked to other robotic teams. When I continue onto college, I know that learning 3D design in high school will greatly benefit me when I am asked to make a prototype.