As it comes out of the box the Elegoo Tumbeler is a very well equipped robot and does not need any upgrades to preform the tasks it was designed for however since we want to repurpose the robot to preform tasks it wasn’t designed to do we must make upgrades to it so that it is effective in the manner we want it to work.
In the project brief we were told to create a supporting front wheel attachment that will allow the robot to navigate the course we designed without the self-balancing function turned on. After testing the single support wheel I decided to upgrade the support system with the pseudo wheelie bar mentioned on a previous blog. This device has multiple purposes.
At rest this device holds robot in a perpendicular position to the ground this is very important for when the robot stops at the end of the course to have the ping pong balls shot into the receiver. When stopped it also provides support to the buggy when the balls land in the receiver as without the back wheel the buggy my fall backwards due to the force imparted to the buggy
The rear wheel is also very important in the driving and turning of the buggy as like with all electrical motors the buggy motors provide instantaneous torque it this wheel was not there the buggy would rotate backwards to the point of flipping under any intense acceleration. Without the rear wheel the robot would have to move very slowly and then the course would take a very long time to complete. A way around the large torque problem would be torque vectoring as is done in EV cars however this would be quite tedious to do and my rear wheel design preforms many functions that torque vectoring does not.
The next design upgrade that I made to the robot was adding the pingpong ball receiver. The container that I chose was a lunchbox of the recommended area. I chose a lunchbox with high sides as I had a modification idea that would negate the high coefficient of elasticity in the reaction between the lunchbox and the ping pong ball. In order to securely attach the lunchbox to the robot I drilled holes in the lunch box that corresponded to holes in the top plate of the robot. I then used a heavy shoe lace to securely attach the box to the robot. The screws on the top plate acted like dowels and hold the box in an even more secure position when combined with the string.
The idea to stop the balls bouncing out of the box was to line the bottom of the box with sponges. The sponges absorb all the energy of the ball without imparting any energy back into the ball as that would make it bounce out of the box.
The additional wheels made the addition of the box a seamless addition in terms of functionality as without it them robot would have struggled to preform the desired tasks even with the self balancing functions working