RC Baja Buggy
Drivetrain & Chassis
Testing
The testing performed on the RC Baja buggy was primarily based on the performance during operation to meet the requirements set in the project report. The testing must be completed to ensure the vehicle will perform successfully for the ASME Baja course event. The RC vehicle must perform in the slaloms, linear top speed, and the Baja course at a reasonably fast time. The vehicle was able to climb and travel in a linear fashion with little to no issues. All testing will be conducted and measured using devices like cellphone speedometers and tape measurer.
The following test are top speed, acceleration, and chassis deflection. These three tests are crucial to the performance of the vehicle, that is why it was chosen over the other types of testing.
Test 1 - Top Speed
Figure 4.1 - Start Line
Figure 4.2 - Phone Mount
This test measured the top speed of the vehicle. The test was conducted in an open parking lot with minimal to no obstruction around. The requirement for this test was 25 mph which it met only using 75% of its power. The top speed calculated was 27.24 mph.
There were 5 trials for each power level, 25%, 50%, and 75%. At 25% the top speed reached was 16 mph, at 50% it reached 22 mph, and at 75% it reached 27 mph. Since 75% power reached the requirement, 100% power trials were not conducted.
In Figure 4.1 picture, it shows the vehicle lined up on the starting line with the phone mounted to it to record.
In Figure 4.2 picture, it shows how the phone mount is connected to the phone case. The mount used is a quad lock 3D printed.
In Figure 4.3 picture, it shows the raw speed data collected for the different trials of testing.
Figure 4.3 - Raw Speed Data
Test 2 - Acceleration
Figure 4.4 - Starting Line
This test measured the acceleration of the vehicle. The test was conducted in an open lot with minimal to no obstruction around. The requirement for this test was 20 mph in 5 seconds (2.93 ft/s^2) which it met only using 75% of its power. The vehicle's top acceleration calculated was 7.331 ft/s^2.
There were 5 trials for each power level, 25%, 50%, and 75%. At 25% the acceleration reached 2.2 ft/s^2, at 50% it reached 2.6 ft/s^2, and at 75% it reached 5.4 ft/s^2. Since 75% power reached the requirement, 100% power trials were not conducted. The last two trials of 75% power were not completed due to the vehicle steering servo breaking.
In Figure 4.4 picture, it shows the vehicle lined up on the starting line with the phone mounted to it to record.
In Figure 4.5 Video, it shows the app capturing the speed and time for acceleration calculation.
In Figure 4.6 picture, it shows the acceleration data collected for the different trials of testing.
In Figure 4.7 Video, it shows how the testing process was conducted. Starting at the line and finishing at the 50 ft mark.
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Figure 4.5 - Acceleration Recording
Figure 4.6 - Acceleration Data
Figure 4.7 - Testing Process
Test 3 - Chassis Deflection
Figure 4.8 - Testing Setup
This test measured the deflection of the vehicle using the Instron machine. The test was conducted in room 127 in the Hogue building at CWU. The requirement for this test was less than half of an inch of deflection with a 20 lb load. Based on the results gathered (shown in figure 4.11) the chassis was able to withstand the 20 lb load with only 0.18 in of deflection. Additional tests was conducted to see how much force it requires to deflect half an inch, the result came out to 60 lb.
There were 5 trials conducted for the 20 lb load, The medium was 0.18 in of deflection. This met the requirement set for the chassis.
In Figure 4.8 picture, it shows the chassis in the Instron fixture preparing for the testing.
In Figure 4.9 picture, it shows the chassis deflecting half an inch with 60 lb load.
In Figure 4.10 picture, it shows the software interface for the Bluehill Element program.
in Figure 4.11 picture, it shows the raw data collected for all trials.
Figure 4.9 - Deflected Chassis
Figure 4.10 - Instron Software
Figure 4.11 - All Trials Data Table