“3D CAD-Designed VEX V5 Robot for Competitive Robotics

Hi, my name is Ishan and I'm going to 9th grade in Dallas, Texas. I'm part of a Vex V5 team who are participating in the upcoming Push Back season. I designed a robot with Vex V5 approved parts that would meet all the requirements to participate in the competition. I had tons of fun while designing this robot and facing all of the tough challenges that came along the way. I hope you enjoy!

Pushback is a VEX V5 competition game in which there are two alliances, each consisting of two robots, and both alliances are trying to score points by moving blocks into scoring areas of the field. The field is divided into zones; teams can score more points by placing the blocks into a higher value zone. Teams can also play defense by pushing the blocks out of scoring zones or even blocking to not allowing their opponents the opportunity to score points. The scoring zones are placed at different heights with the tallest one being at 25 inches. The game is all about speed, control, and strategy. Teams must try to balance scoring or offense with slowing the other teams down or playing defense in the time allowed.

Use one of many CAD (Computer Assisted Design) softwares like Fusion 360 or Onshape to name as the most simple. These softwares allow you to CAD using a variety of parts that can be imported from different websites or used as a simple tool to design items with. In this CAD, I used Onshape to design my robot.

The first step of designing anything, is sketching it! Having a basic drawing can be an easy way to understand how you would want your design, or in this case a robot, to look like. I built my robot after looking after tons of other robots to really understand what strengths my robot would need. The first need that my robot needed was to be able to store a mass amount of blocks. This is where I sketched the storage part of my robot where I made 2 separate tanks which can store up to 6 rings each bringing it to a total of 12 total blocks. A motor inside with a chain connected to it would help push all of the blocks out of the system when necessary.

My second need was a robot that would be fast but not so fast that it would go out of control. I decided to use a total of 6 motors splitting it with 3 motors on each side that had a blue cartridge. A blue cartridge means that it rotates 600RPM (Rotations Per Minute). I put a gear train that had 2 gears that would essentially slow down the speed of how the motors powered the wheels to 450RPM allowing me to maintain a good handling speed.

With my main components finished, I finished sketching out my design and added anything necessary for these to work like a Pneumatic Piston powered by pressured air that would help lift the storage system up and down to the level of the goals.

Using the CAD software Onshape, I began my process of CADing my Drive Train (DT). The DT is an important part of a robot because a slow robot can let my opponents score more points while a fast robot would make it unstable and prone to overheating. I decided to move forward with my original plan of 4 wheels that had a 450 RPM. I made both sides of the DT and connected them together with cross braces and multiple connection points that would keep the DT straight and not bend inwards which would have made it slower as the damage continued.

I then began the process of creating my storage system that would be responsible for holding all of the blocks. The storage system would be covered in aluminum plates which are both light and thin enough to create enough space for as many as blocks as possible. It has a chain right in the middle of the 2 areas with all the blocks inside of them to help push all the blocks when needed into the scoring area.

My next step was to create the miscellaneous items like the roller intake that would be responsible to push the blocks up the storage system. Another item was attaching pneumatic pipes powered by air pressure to help push my storage system up and down based on the level of the scoring zone. With the highest height being 25 inches, I would need pipes that would be able to push my system that high.

My final step was screwing and connecting everything together with the proper size screws and connection points which would make the robot stable. The more connection points, the more stable and balanced the robot would be when put into situations. I also measured my robot whether it would fit inside the limit of 18x18x18 inches range because robot's that are out of size aren't allowed at the competition.

Below are some of specially designed items for my robot. I've attached my Custom Designed Rubber Band and cut up gears.

The most important part of this process comes down to solving the variety of challenges. One major challenge that I faced was how my intake rollers were blocking a part of my storage system making it inaccessible for blocks. This major problem brought my total blocks that I could store in half. I started brainstorming to how I could solve this problem. I decided to come up with several different solutions, bring the pro and cons of those solutions, and decide on the best one. My options were as listed below:

1. Somehow move my pneumatic system so that I could align the storage system to which its one side wouldn't be as inaccessible.
2. Pros: Would solve my problem without having me change my storage system at all.
3. Cons: The C-Channels holding the pneumatic system up would block the system entirely forcing me to do a full redo of it.
4. Move my chain in the middle of the system that helped push the blocks out a bit back allowing for enough space in the front to allow the blocks in.
5. Pros: Would solve my problem without forcing me to change any of my pneumatics and intake rollers.
6. Cons: Might allow blocks to slip out of the system if enough gap is created from the changes.

My final decision that would have minimal changes was option 2 with it only requiring me to change the position of the chain. The pictures above show the difference between the two chains now with the left chain being pushed back significantly enough to keep it accessible for blocks.

I hope you had fun going thru the journey of how I made my Vex V5 robot!