Construction:
The construction phase of the RC Baja has begun in the winter quarter of the 2024 school year. During this construction phase all RC Baja steering and suspension components needs to be complete so that at the end of the quarter in March of 2024 the parts are finished and the output is such that the RC Baja is functioning and operable.
Majority of the RC Baja's suspension components are waterjet cut via SendCutSend to enhance the amount of accuracy that is achieved. All parts are waterjet cut during the first 2 weeks of the quarter, after the parts are waterjet, the holes that are needed are then drilled and tapped. Once all drilling and tapping operations have been done, the parts are then deburred and all sharp edges are removed. During the first 4 weeks of the quarter, all waterjet cut parts were complete and ready for assembly.
Some parts were also needed to be machined, the parts that were machined are the rear trailing arms, mounting brackets for the trailing arms, and any necessary modifications to parts that are either buyout, or pre-existing waterjet cut parts. Up until week 4, raw stock had to be cut and milled down to the right size, slots had to be made to allow for the correct spacing for components, and any drilling and tapping had to be done for the correct fastening locations. Much like the waterjet cutting that was done, all the parts that were machined went through a deburring process to remove any sharp edges/surfaces that may pose a threat to cutting open the user's skin.
There were minor setbacks during the manufacturing process but because the engineer was consistent and disciplined there was plenty of extra time at the end of the quarter to make any small changes to parts that needed to be done. And since the engineer was done manufacturing most of the parts that consist of suspension and steering, the engineer was able to help manufacture parts of the drivetrain and chassis to speed up the manufacturing process for the rear axle even though the engineer was not entirely responsible for doing so. But because of that, the car was drivable 3 weeks ahead of schedule.
SolidWorks Drawing Tree:
Manufacturing:
Figure 10. Waterjet Cut Parts
In figure 10, the steering and suspension components are shown prior to being taken out of the raw material sheet of 1/4" aluminum as well as the two steering arms that are located at the top left of the sheet. These parts are broken out of the sheet that they came with and then holes are drilled and then tapped like mentioned above.
Figure 11. Front Suspension Partly Assembled
Shown in figure 11 is the partly assembled front suspension sub-assembly. The upper, and lower control arms are shown connected to the knuckle and bulkhead. The holes that were drilled and tapped are also shown, on the lower control arms four threaded M3 holes are there to serve as a mounting location for the lower shock eyelets to mount to.
Figure 12. Beginning of Rear Trailing Arm Manufacturing
In Figure 12. the beginning steps of manufacturing the rear trailing arms are being began. The first step was to find a piece of raw stock aluminum that fit the needed dimensions of the design, and then to measure out 3.5" of length to cut the raw stock material to to satisfy the length requirement of the rear trailing arms. From there the horizontal band saw that is shown in the timelaps in Figure 12. is used to complete cut.
Figure 13. Vertical Milling Operations of the Rear Trailing Arms Time Lapse
In Figure 13. after completing the horizontal band saw the milling operations are next. And since the raw stock material that was chosen was not perfectly square, nor did it have flat faces, all 6 sides of the raw stock was faced so that all sides were flat and all operations are accurate and consistent.
Figure 14. Rear Trailing Arms Raw Stock After Being Faced
In Figure 14. the raw stock is shown what it looks like after it had been faced and the correct overall thickness of the trailing arm has been achieved from the mill. This raw stock is enough material for both rear trailing arms, as the goal is always to achieve the maximum amount of parts out of a certain amount of material and nothing goes to waste. From hear, two seperate rear trailing arms can be made and are shown in Figure 15.
Figure 15, Rear Trailing Arms Split Into Seperate Arms (Left and Right)
Figure 15, shows the left and right trailing arms after they had been separated from the raw stock in which they came from. Since the horizontal band saw is not equipped to make a cut out of material as small as this because of tooling, the first instinct is to just use the vertical band saw, however at CWU, the vertical band saw has an extremely inefficient blade to cut through Aluminum from being dull. The engineer decided to just take a 1/4" end mill and split the raw stock evenly and end mill through the material down the middle, and the result is 2 cleanly cut pair of trailing arms.
Figure 16. Drilling Ends for Heim Joints
In Figure 16. The ends are being drilled. Generally the drill press is used for this operation, but the engineer has higher confidence achieving higher accuracy and precision using the vertical mill to complete the drilling operations. Up to this point of manufacturing the rear trailing arms, there have been shock mounting holes added on the sides, a slot has been milled out for the shock to pass into, and the ends are being drilled as shown in the picture. All of the holes drilled are tapped with M3 and or 1/4-28 threads. The reasoning for choosing metric and imperial taps are for availability the the engineer has to screws and bolts and tooling provided by CWU.