Testing
Figure 8: Crusher Diagram
There were two areas of focus for testing of this project mapped out in Figure 8. Deflection was observed at the input side wall of the crushing housing and the area underneath the housing. The goal of testing was to observe deflections within the requirement for maximum deflection at 0.005 inches.
Three different tests were conducted. The first two tests were conducted by manually driving the crushing wheels. The first test was conducted with partially delaminated carbon fiber composite and the second conducted with full carbon fiber composite strip. The remaining test was conducted by driving the crushing wheels with the motor connected to a VFD.
Figure 9: Manual Driver
Manual tests were conducted with the removal of the crusher chain guards and shredder housing. These were removed to access the input side wall of the crushing housing. The shredder housing was removed to drive the recycling system with the wheel shown in Figure 9.
Testing Device
A magnetic base dial indicator was the tool used to measure the deflection of components produced by the crushing load from carbon fiber delamination. The dial indicator was set to zero at each testing location after it was secured to a location along the supporting table. The arms of the indicator were angled in different positions for each test to ensure an accurate zero at the location of testing. Figure 10 shows the testing device and components.
Figure 10: Magnet Base Dial Indicator
Testing Locations
The main focuses of testing were to observe deflections about the crushing housing. To produce relevant testing data, locations underneath the plate of the crushing housing and the side wall of the housing were chosen. Figure 11 shows the indicator placed 13 inches up and 10 inches to the left from the bottom front corner of the crushing housing. Figure 12 shows the location at the upper back area of the housing side wall.
Figure 11: Test Location Underneath Housing
Figure 12: Test Location Upper Back Side Wall
Demo of Testing Procedure
Results
The following tables shows the deflections recorded from each test. Each test has a column for the testing location, predicted deflection value, actual deflection value, and the direction of plate deflection. The predicted value for deflection underneath the housing was 0.004 inches and for the side wall less than 0.001 inches. Table 1 shows data for the partially delaminated manual test, Table 2 shows data for the full composite manual test, and Table 3 shows data for the motor test.
Table 1: Test 1
Table 2: Test 2
Table 3: Test 3
Testing Results Summary
The actual deflection values for the manual test show the deflection of the side wall to be greater than the predicted value and greater than the requirement of 0.005 inches. However, the deflection underneath the housing falls within the predicted deflection value and the requirement of maximum deflection at 0.005 inches. The motor test needed modification to delaminate carbon fiber composite without breaking any system components. The crushing wheels were not stable enough to crush 1/2" thick composite, therefore 1/4" thick composite was used for testing. At an input of 189 rpm and output of 0.5 rpm, the crushing wheels produced the same deflection of the base plate as the manual test.
The system failed to meet the requirement of crushing 1/2" thick carbon fiber composite at a crushing speed of 2.5 rpm and to reduce deflection in the side plates less than 0.005 inches. However it was successful in connecting all the components to a singular part and reducing the deflection of downwards motion to under 0.005 inches. The system is way more functional than what was started with. Testing showed that more focus is needed to secure the crushing wheels tighter on their keyways and that the side walls need to be redesigned to carry the loads produced by the crushing process.