Welcome back to the REV blog page, post number 10, and we are happy to say that the REV moves!
Over the last two weeks, members of project REV have made a few strides in progressing with major systems.
One such progression is having the motor in and tested. Students from the auto shop worked to mount the four 12 volt batteries into the front of the vehicle. We took readings of the weight at each corner of the vehicle to see if the batteries might prove too high a load on the steering system.
The grade 10 students discovered that by moving the battery pack closer to the rear of the vehicle caused less strain on the steering system up front. This is a major consideration in providing the best possible comfort and efficiency with regards to the handling of the REV while in motion.
Our big milestone was getting the vehicle to finally move under its own power! With the brake cables installed in a temporary fashion, one of our students boarded the REV and was able to get it to move slowly across the shop compound!
The celebration was wonderful, but not without a hitch. We quickly discovered that the chain fell off the motor on deceleration and jammed the sprocket gears in the axle, thus causing the entire motor housing to bend and deform!
Soon it was back to the drawing board to figure out how to minimize jamming.
While brainstorming, a team member decided to look at the original design to see how Mr. Ford laid out the motor drive and that's when we decided to try temporarily mounting the motor much forward of the drive sprocket, instead of above it.
By changing the location of the motor drive, subsequent test runs kept the chain from jamming, though the chain did still occasionally fall off. We will brainstorm ways to keep the chain tensioned as we work to redesign the new motor mount.
Moving along, it was important to complete the braking system by adding in the "AB Handle," or Accelerator/Brake handle. Henry Ford did have a handle on his quadricycle for throttle and gearing, but the innovating machine had no need for brakes 128 years ago. We decided it very important to add a brake to ensure the vehicle's safety for riders.
A little more brainstorming led to senior students building a double action lever, which, when tilted forward, will push on the electric accelerator pedal, then when pulled back, will release the accelerator and apply the brakes by pulling on two brake cables.
Interestingly, Henry Ford's first vehicles produced had mechanical brakes. He was determined that for safety, his vehicles would employ "Nothing but steel-from brake to wheel." In tribute to Mr. Ford, we added a similarly principled device to the REV by using bicycle brake calipers and cables.
Continuing on with the redesign of the motor mount, we discovered that the temporary wooden motor mount flexed under torque, so our Engine Rebuilding students took to welding a new all-steel longitudinal mount for the motor, to keep it stiff and strong during acceleration.
As the main brake system is ready for testing, our Engineering students are measuring pulling power of the linear actuators we hope to add to the brake to help stop the vehicle as part of a Radar Brake system. If the vehicle detects an object during motion, we hope the system can alert the driver and slow down the vehicle to minimize an impact.
Coding is underway to design an Arduino-based system to read proximity via radar, and calculate and operate the warning and brake systems for the REV...
And finally, this week students assembled the electrical portion of the old school bell system for the REV, after installing the bell on the front fascia, they ran the wiring to the battery and switch on the swing arm to activate the bell with success!
Tune in soon for Post 11, as we get test and refine more vehicle systems together and see the final steps of Project REV get closer to the finish line!
See you soon!
