V1 Upgraded Body Panels

One of the main concerns we had with the nose panels during competition was accessibility to the steering and braking systems. Since the panels were fastened to the frame members with nuts and bolts, making adjustments to these systems proved to be tedious and time consuming. In addition, there were a total of nine panels that covered the nose – which meant that the time taken for removal and re-installation would cost us with time we had left in the endurance. In order to solve this issue, the body panel’s team came up with a design which would give the front nose panel quick-release capability and reduce the total number of panel’s from nine to three. The new front panel will be fastened to the frame with cotter pins and hinged to the lower front member with hooks. During removal, it will swivel outward from the bottom as one piece and detach from the member – taking only a matter of seconds. The new nose side panels will replace the six panels used previously and will remain fixed in their positions as all the systems can be accessed from the front with enough clearance. Our next steps are to get in the shop and start work on manufacturing the panels. Stay tuned to see our progress!

-Saf

V1 Fuel Spill Guard

The new design of the fuel spill guard will eliminate the attachment to the rear member and improve how the fuel drains.

The initial concept was for the fuel spill guard to be manufactured by thermoforming. Recently it was realized that we overlooked the fact that the part is close to the exhaust which would probably melt the thermoformed plastic. This overlook showed us the significance in remembering to look at the big picture when designing a component, instead of just focussing on the part itself.

The new concept, seen below, is made of sheet metal and will cover the engine and exhaust. A cylinder of sheet metal will be welded to the plate, forming the drip pan meeting the requirements specified in the rules. Still in progress is the design of the drip pan to allow all spilt fuel to drain with no pooling and how to attach the spill guard to the fuel tank.

V1 Brake Pressure Switches

After bleeding the brakes on November 12th, the brake team performed calculations to determine the force applied on the brake rotor.  Through confirmation from the pedal box team, a 6:1 ratio was determined for the brake pedal lever.
Using this information and the size of the master cylinders, it was determined that a pressure of 1429 psi would be reached in the brake system when 150 lbs was applied to the brake pedal.
This presented a problem for determining the appropriate pressure switch. The majority of the pressure switches on the market for automotive uses are typically rated for a 750 psi burst pressure, which is below the required 1500 psi based on the calculations.
After researching and not finding a common pressure switch with the required maximum burst pressure, it was determined that an automotive grade pressure switch would be sufficient despite its low rated maximum pressure.
Moving forward, the brakes team will submit a purchase order for new pressure switches. After the order is completed, physical work on the car completed. The brakes team will be working with the pedal box team to relocate the brake lines for ease of maintenance and installation of the new pedal box. The brake line running through the cockpit will be moved from its current location at the the floor of the roll cage to the top of the side wall. This will make bleeding of the brakes easier and reduce the risk of air bubbles being trapped in the brake system by reducing the overall elevation changes of the brake system.


Upgrading the Engine Mounts

Over past few weeks the engine mount team has focused on solving the vibration issues of vehicle and has made some good headway. Both Manny and Sherj spent time in the school’s Plastics lab to cast samples of polyurethane with varying durometer ratings. This durometer rating dictates the hardness of the polyurethane, which in turn affects other key properties of the polymer. The plan for this polyurethane is to insert it between the engine and the mount so it can act as an isolator, hence damp vibrations.

engine mount polymers
These different samples of polyurethane will undergo tests to determine specific properties, such as flexural strength and toughness. The data these tests provide will help the engine mount team to decide which sample of polyurethane will best suit the vehicle.

Once a desired durometer rating for the polyurethane is selected, it will be cast and machined into the desired geometry and installed on the vehicle.

 

Background Research

With these generic multi use engines, the possibility of mounting is quite large. For this particular example we took a look at everything from, compressors, water pumps and generators to ATV’s, UTV’s and racing karts to see if any particular method used could solve or help solve the particular issues we have isolated for this redesign.

The research into tools with similar motors mounted, didn’t really provide anything of use as most were just solid mounted with a simple design, due to it being a stationery design. The research into what we consider similar vehicles gave us an idea of how vibration is dealt with but not really anything in particular to help with our specific design. Most of these similar vehicles do not use solid mounts like our original, but rather have some kinds of anti-vibration materials added, (ie polyurethane or rubbers of different kinds). These ideas are great for those applications but rubber due to the excessively minimal slack allowed by the CVT is not really feasible for us, the polyurethane is something we may look into more due to its lack of flex.

Design wise there aren’t any mass market products that could be directly used or referenced. The most detailed and engineered design on the market currently would be used for racing shifter karts. These karts have similar issue as the Baja Buggy in that vibration and mounting point stress are very key in design.

 

The current car has competed in the 2015 Collegiate Design Series in Oregon. Aside from several components failing, there were other apparent issues. One of these issues were the members holding the engine. These members were unsupported for their entire length, causing the members to deflect a relatively large distance. Allowing the engine run in such a state for prolonged periods of time could lead to a catastrophic failure of the members and possibly damaging other valuable components. There were no calculations or simulations done to examine the unsupported member and whether or not it could fail through fatigue.

engine mounts
Figure 2: The Current V1 Engine Mounts

To solve this issue, the unsupported member can be braced using the engine mount and the frame members surrounding the transmission. This can be accomplished in a multitude of ways. The most simple of these is to weld the unsupported member to any adjacent frame member. The major advantage to this would be the amount of time and resources saved to fix the problem. The major downside is the welds would cause major restrictions. Currently, the engine can freely slide the entire length of the member it is supported by, allowing for easy tensioning of the CVT belt as well as a simple removal process for the engine. An engine mount that would allow for this freedom could involve a clamping system. This system would look very similar to what is currently being used but it would have an additional extrusion in contact with an adjacent member to act as the clamp. This extrusion would also consist of another piece placed on the other side of the member and bolts to hold these two pieces together. This design would allows for free movement after the bolts are removed, but would still provide support. Optimizing this design could also save weight as no simulations were done to test if material could be removed.

 

Vibration

 

Another issue with current engine mount is they are currently hard mounted to the frame. This causes a severe transfer of vibration to the member supporting the engine as well as throughout the entire car. This vibration has the potential to cause failure in a multitude of components such as the electronics, so it must be looked in to. There were no calculations or simulations done previously to determine the exact impact of the vibrations.

A solution to this problem could be the use of shims. The shims would be inserted where the engine mount clamps onto the frame. The shims could be made of rubber and would isolate the engine from the engine mounts. It is this isolation that would damp vibrations. A downside to these rubber shims is they may affect the tension in the CVT belt.

Other teams had varying views on the subject of engine vibration. Some teams had no need for vibration damping; they left the engine hard mount to the frame. There were other teams who had severe vibration and used either flexible or solid inserts to damp vibration.

 

 

Casting

Currently, the engine mount is stock 2×2 aluminum that has notches cut out with a ball mill. Holes were then drilled to bolt the engine to the mount, and then the mount to the frame. Instead of using stock aluminum, the casting of aluminum parts could be done. This has the major advantage of confirming the viability of casting future parts. This will allow future teams to create part geometries that would otherwise be very difficult to machine.

The new engine mount could be casted from a different aluminum alloy to maximise the desired qualities such as castability and machinability. A composition that would do this is Aluminum 319, which is an alloy containing 6% silicon and 3.5% copper. This type of aluminum alloy is commonly used for engine parts, which makes it a prime candidate for an engine mount.

Another aluminum alloy that meets the required machinability and castability properties is Aluminum 356. Aluminum 356 contains 7% silicon and 0.3% magnesium. It is also used for flywheel castings, automotive transmission bodies and pump bodies.

with the faculty at BCIT, casting different alloys is possible. This will involve using an uncontaminated crucible and sourcing the correct materials to achieve the desired composition.

V1 Electrical System Review

A few of the major improvements that needed to be made to the electrical system was that the power supply was too heavy, and that maintenance was going to be difficult if it needed to be done. Also, due to changes in the rules for the 2016 competition a new brake light needed to be purchased.
After some quick calculations, it was determined a simple 9V battery should do the trick, which is a significant weight decrease from a golf cart battery. This year, the car will not be equipped with reverse, making the overall circuit simpler and easier to install. In order to simplify installation and maintenance, more connectors will be used and the new brake light features two holes on the sides for mounting. Last year’s brake light was mounted using a grommet, so if the light needed to be removed, it was easier to take off the entire mounting bracket which was mounted a little too close to the firewall, making it difficult to use any tools. A new mounting bracket is going to be made this year once the brake light comes in and measurements can be taken, and will be mounted in a way that will be more easily accessible. The new brake light also allows for removal while leaving the mounting bracket in place.
-Oliver


New Seat Design

This year, BCIT Racing’s Seat Team had the opportunity to design a brand new seat. In the previous year, the seat that was used proved to have some limiting factors, such as weight and size, that were not allowing the car to race at its full potential.

Come November 13, the team came to a conclusion on the type of seat to design, as seen in Figure 1. This design has the potential to improve all the limiting factors and provide a much more efficient ride for next year’s competition. Currently, it is still undergoing some revisions as the team makes small adjustments to the design to verify that it meets all of Baja SAE’s requirements as there were new requirements and revisions to the rulebook this year.

 

We are planning to make the structural seat components out from carbon fibre or fiberglass in order to reduce the weight that was a major issue in the previous seat.. The red padding as seen in Figure 1, is used to improve the comfort of the driver and will be made out of some sort of closed cell foam that will have properties that remain constant, no matter the conditions and will be relatively wear resistant. The foam padding used in the previous seat was designed for the Temperature controlled interior of a car, after the race it was evident that this could greatly be improved upon.
After the manufacturing process is finished, we will have a lighter, smaller and more functional seat than the car seat used in last year’s race.

-Victor

Bleeding the Brakes

On November 12th, the Brakes Team collaborated with the Pedal Box Team to bleed BCIT Racing’s Baja SAE car’s brakes. The purpose was to check on the condition of the brake fluid inside as requested by the Team Captain, Jeff Meiklejohn.
The automotive technician experience that Alex, from the Pedal Box team, proved invaluable as he led the group in the procedure of bleeding the brakes.
However, midway through the procedure disaster ensued. While pumping the brake pedal the pressure switches exploded! Thankfully, we all were wearing personal protective equipment so no one was injured.
In the picture below, you can see the result of the broken pressure switch. Pressure switches are required to activate the car’s brake light as per SAE rules. In the meantime however, we simply plugged the T-ports with NPT plug fittings to prevent the system being exposed to air and to stop any leaks.

Moving forward, the brakes team will select pressure switches that are capable of handling the pressure generated by the master cylinder.

 

-Blanco