Quick Angle Adjustment
Entry ID #: 8775
Created: Mon, Dec 7, 2020 8:49 PM
I am Mattias Peroni from team Jelly 2733J, and this is our entry for the 2021 VEX Robotics Competition “Make it Real” CAD Engineering Challenge sponsored by Autodesk. The part we have designed and printed is capable of holding sheet metal and plastics at a desired angle or bend. When building something that needs to hit a target, we look to have precise aim and adjustability with our design. Therefore, it is important to find the right angle of the launching mechanism. This would have been a great piece to have for this year's challenge where balls have to be placed in a certain area but also in past games like Change Up or Nothing But Net.
With this piece, the process of finding the perfect angle would be sped up. It would simplify making adjustments of an angled or bent piece of metal or plastic. Additionally, it allows for more precise adjustments than what is currently possible with the VEX structure and motion components.
To make this piece I used Fusion 360 (version 2.0.9313). This is the software I have used the most because it has a free student download. I initially learned to 3D design using Tinkercad as I only had a laptop and it could only handle so much, but I moved to Fusion 360 as soon as I could. Fusion 360 gives me the ability to create parts quickly with guaranteed accuracy for 3D printing.
To make this piece in Fusion 360 I measured an existing aluminum vex piece to find the correct spacing and size of holes. I then sketched a 12.9mm by 127mm rectangle to act as the perimeter of the sliding mechanism in the new part. Centered in this rectangle is a 4.623mm by 123.544mm rectangle that will be used to cut the area where a screw would go through. I extruded the area that would be attached to a physical piece to 1.6mm. Next to that I extruded the rectangle sketch of the slider to 10mm. I then chamfered the top inside edges of the slider to 3mm in order to create an area where the piece that would slide could rest. I then created a sketch on the bottom of this new part to create an area where a nut could be placed and not spin so that tightening could be made easier. To accomplish this, I sketched an inscribed polygon with an edge length of 4.733mm. I then mirrored this across the center of the slider and connected the two hexagons with lines. I then cut the existing bodies with the previous sketch by extruding it -3.5 mm. I then added to the previous sketch by making lines that I would use to create the chamfers on the edges of the piece that would connect to the robot. I did this by sketching a line on the top right corner at a 45 degree angle and setting the length to 2.233 I then set restraints to make it fully defined. I then repeated the process on the other side and cut the existing part with the face the line had created. Next I filleted the insides of the squares that allow screws to go through them with a radius of 0.508mm on each corner. Next I used the move and copy command to copy the piece I had made to create a 90 degree brace. I rotated it 270 degrees so that it would line up correctly. I then copied the same piece and rotated it 45 degrees. Using the extrude command I deleted the area that had the squares so that the piece was only a slider. I then figured out the correct measurements to make the two 90 degree edges able to be connected to VEX pieces. Supporting braces came next in order to make the piece stronger. Any remaining areas were then chamfered to create a clean looking part.
In this project, I learned how to make slider joints in the assembly side of Fusion360 which I used to create Version 1. I also learned that a rectangular slider works better as it does not tilt. I did not realize that until I printed the first one round. Slider 2 v.2, locked in with more stability. I was also reminded again about the importance of measuring well. The alignment of Version 1 was off. I used my micrometer but not well enough. When it was clear to me that the holes did not line up, and I started over with Version 2, I used available VEX piece CAD files. I didn’t import it into my design but used it for correct measurements.
Fusion 360 allows me to design and print cool accessories to use on my robot (and my sister’s VEX IQ team robot), but this year we also printed scoring objects as 2733J is a homeschool team and do not own a field. Using Fusion 360, I can also CAD our robot design so we can show 3D renderings in our Design Notebook.
I really enjoy the prototyping part of the design process and 3D Printing is something I hope to work with as I join the workforce. My current hobby is designing, printing and CNCing lightsaber hilts. I then install a blade with custom programmed LEDs to create fully functioning lightsabers with sounds and lights that change depending on the speed you swing the blade. I have also been asked by family friends to design prototypes for them of ideas that they have for cool products, but that they can’t do themselves. I also use Fusion 360 and my CR10 3Dprinter for hobby printing as well as designing stuff for my dirtbike and around the house. I made wheels for our dishwasher when they broke which made my mom very happy and I also designed a hook that I named the “infinity hook” and sold a few at our Dirt Bike races.