Wednesday, October 14, 2015

Update - 10/10/15

Week five of the new EVT semester!

On the MechE side, the Suspension Subteam continues to work at redesigning the Opel's suspension. 

Suspension Design 101 with Jimmy Handy 
The team is reworking the subframe holding the suspension and powertrain components:

"The old design for the subframe used non-right angles to make it smaller, however, especially in the prototyping phase, mitered angles are more difficult to cut than straight across." - Jacob Fisher

Powertrain subframe assembly

The EE subteams are also making headway on their projects.

Several new EE's have finished schematic capture for the CAN dev board and are currently finalizing PCB layout.

Others are working on a wheel velocity sensor that will transmit to subscribing modules on the CAN bus.

Stay tuned for more updates! 

Saturday, October 3, 2015

Update - 10/03/15

Lot's of progress being made by the Opel sub teams! 

Here are some of the things members did this week:
  • Installed and began learning KiCad
  • Began schematic capture for CAN dev board 
  • Characterized hub motors for voltage, frequency parameters
  • Took measurements of stepper motor dimensions for PCB footprints 
  • Installed and began learning SolidWorks
  • Began mockup of front compartment and cooling system
  • Set up firmware and hardware templates for electrical subsystems
  • Learned about CAN communications
  • Got two LPC uControllers talking to each other over CAN bus

Saturday, September 12, 2015

First meeting of 2015

A new year, a new batch of awesome freshman, and a lot of work to be done!

On the electrical side, the team is focusing its efforts on the development of several key components of the car architecture: driver interface, user interface, motor interface, throttle interface, low voltage system, gauges, and wheel velocity sensor. 

Alison (gauges):
"My group went through a small tutorial to introduce [freshman] to CAN - the communication protocol we'll be using in the Opel. Some of the topics we covered to get to this point included:

  • Microcontrollers
  •  How CAN works at the physical level
  • How CAN works at the software level
  • Sending messages over CAN
  • Checking if messages received over CAN contain specific data
  • General C syntax
  • Bitwise operations

Ultimately, we were able to get two microcontrollers (LPCLLCX4?) talking to each other over CAN, and sending each other messages that caused an LED to turn on or off. In the future, members will apply what they learned to focus on a specific component on the CAN bus - the user interface.

Skanda (driver interface):
"Our group started to flesh out the design for the electrical subsystem that accepts driver inputs (e.g. turning on headlights, blinkers, windshield wipers, etc.). We worked with our new members to make sure they understood the subsystem's basic architecture (switches -> LPC controller -> vehicle CAN bus and peripheral relays). After that, we took a look at Hugo's specs and decided on some of the relays that we should use, and the driver interface casing. We also thought about how to fit in our goal of having different car performance settings (sporty and non-sporty, with different throttle profiles). We indicate on the bus (with designated non-conflicting CAN ID x800) which setting our car currently is set to, after which the throttle subsystem should adjust its output accordingly."

Joey (batteries):
"Battery sub-team introduced perspective new members to the design considerations we are facing with weatherproofing the front cabin, cooling the batteries, and mounting the batteries. We came up with some preliminary solutions for the weatherproofing of the cabin and cooling the batteries. Next steps are to test the preliminary solution we came up with, and to research more about air flow to determine if there is a more optimal method of both cooling and waterproofing."

In addition to the Opel conversion, the team is kicking off a new motorcycle project, headed by Jimmy Handy, for the Pikes Peak competition:

We are currently working on creating some Matlab simulations that will allow us to choose the model of Zero that is the best starting point for us. We are looking at the initial cost of the bike, energy requirements for each of the bikes to complete the race, weight, and acceleration profiles. 
The current winner is the zero FX. This is zeros lightest and cheapest bike. We plan on switching the motor and controller from the fastest, heaviest, and most expensive zero to the lighter bike in hopes we can have the best of both worlds.

Friday, January 9, 2015

Opel Tear Down: IAP Marathon I

 For the first time since the summer EVT months, we're getting back to Marathon Thursday meetings!
With just a handful of the crew around, we got started with Antony working on the blog, Eric and Joey learning some solidworks, Jimmy starting a new electric scooter, and I got some work done on my ATV.  After a few more of the troops arrived, we went down to see what we could do with the rusty Opel...

The main goal for the night was to start removing the unnecessary or unusable components such as the exhaust and to start cleaning up the car.  Given the rough shape of the car, we had some flexibility to go to town and have fun tearing apart the car.  After Joey made sure to remove all the hornet and bird's nests, we took a look at what we were up against on the underbody of the car.  Here Joey and Jimmy cut the muffler out with a hacksaw and remove the exhaust pipes:

We took a good look at the rear suspension setup with the panhard bar.  We were having fun inspecting all of the components, and nearly removed the entire rear axle before Eric brought up that we probably want to keep the wheels on so that we can move the car...

We still proceeded to drop down the driveshaft and the transmission.  Jack, the shop manager in D-Lab, gave us a quick lesson on torque tubes and rear suspension configurations.

Opel Driveshaft and Transmission
Next, we brought the car down on the lift and began to take a look at the engine bay and interior.  We ripped out all the dry-rotted tubing and deteriorating rubber from under the hood, and did what was possible to clean it out with a shop vacuum.  Without an engine or any components, there is a ton of space for batteries under the hood!

As we moved to the interior of the cab, the last main task for the night was removing the gas tank.  After ripping out the shelves and other brackets for the spare tire that were concealing the gas tank, we began the removal of the last major, unnecessary component in an electric vehicle conversion.  

This turned out to be a bit more intense of a task than we expected.  The Opel has a large open space in the rear of the car, but no rear hatch for access to this trunk area.  Therefore, Joey and I squeezed into the cab of the tiny car while Jacob and Eric helped us navigate from outside.  

After a long effort to remove all the hard to reach and rusted bolts mounting the gas tank to the car, we had it loose.  It turned out to have a very irregular shape that was difficult to pull up through the tight fit in the cab.   

Then we had yet another unforeseen complication, when we realized that there was actually still a substantial amount of gasoline left over in the tank.  At least this was just as safety-master Rango made his arrival and assured that we disposed of it properly!  With the help of our FSAE friends, we located a gas can and slowly drained the rest of the gasoline into the tank.  

After plugging and capping the openings to the gas tank, we were finally able to remove the tank and waited to consult EHS regarding its proper disposal.  The removal of the tank revealed another substantial open cavity in the rear of the car, optimal for battery placement.  We'll continue mapping out these spaces moving forward, as we continue working to find a suitable battery option for the car.  But for now, the long night of work concluded with our usual late night trip to Beantown Tacqueria!
Open space!

Monday, January 5, 2015

We're Back! EVT IAP Kickoff

With the EVT crew back for the new year, it's shaping up to be an exciting AIBD 2015!  Our team New Year's Resolution is to get back to diligently updating our work and progress on the website!
EVT Trike at the Albany Capitol building!
Despite not having any blog posts to show for it, the last few months have been extremely busy and productive for the Electric Vehicle Team!  Since the summer, we have successfully rode our trike 190+ miles to Albany on a single charge, revamped the Porsche, returned to Mt. Washington, and put an enthusiastic group of freshmen through our EVathon new member training program!

Now that the EVT roster is bigger than ever, we've decided to get back into classic cars and create an electric 1970 Opel GT!  Our faculty advisor, Professor Dan Frey, fixed us up with an old Opel, and we're ready to get started for IAP.  There's a ton of work to do, and a number of members are also working on electric vehicle projects in preparation for the February Techfair, so it will definitely be an exciting month!
Stay tuned for more team progress updates soon to come!

Monday, June 16, 2014

Trike Trailer Prep Continued

This week's meeting featured the highly anticipated return of some more team members to the Milkdrop, as the summer EVT crew is gradually reuniting and continuing to grow!

In preparation for the weekly meeting, the full-time UROP gang set the tone for the meeting with some long nights in the shop consisting mostly of work on the trike along with a healthy dose of messing around on Roberto's motorcycle...



Productivity from the week before carried into the meeting, with the crew up at 6am and off to work finishing up the frames for the trailer walls!  Although the painting was all done, we continued filling the Milkdrop shop with wonderful scents as we applied clear coats of polyurethane at 4 hour intervals.   

 We also finally adjusted the brake cables on the motors so that they're ready for some testing.  Joey added an intermediate wire to run the power wires to the brake motor through the base of the trailer so that we can seal around it with the silicone and still be able to disconnect all the other wires.

Extra connectors for the brake motor wires

After a long, heated debate, we finally decided that it would be best to just tip the trailer onto the back.  Everything was securely mounted and the weight balanced enough that we didn't have a problem tipping up the massive trailer, and we had an optimally convenient way to apply the silicone caulking in all the exposed openings.  This also gave us a great opportunity to clean out all the dirt that had been slowly building up under the trailer.  Erich showed his experience and mastery with the caulking gun as he meticulously sealed up all the edges along the aluminum frame.

Hanna and Joey continued plugging away on the Xbee work so that we can pull the data from the trike wirelessly on the chase car.  Although there was some trouble sorting through the drawer of old Xbees and figuring out which ones still were in working order, we got one set of Xbees transmitting the data from the batteries and almost finished getting another set to transmit the data from the cycle analyst.

Hanna and Joey mastering Xbees 

Friday, June 13, 2014

Trailer Brakes Update

We've been plugging away on the emergency brakes for the trailer for a while now, finally putting up the pics!  Eric and Rango on the Electrical Engineering team worked through all of the electronics for actuating the brakes a while ago, leaving them just to be mounted.

We stuck with the car window motors after being unable to find a solenoid or other alternative that could offer the amount of power that we needed.  Their worm gear drive makes them very powerful, as well as being unable to be backdriven, which is a helpful feature for pulling the brake cable.  One downside to using them was just that they had very irregular shapes, which made them slightly inconvenient to mount.  The position of the motors below the trailer also caused orienting them to require a lot of consideration so that there was still sufficient clearance with the ground.  We also didn't have symmetric models, meaning that we needed to have separate mounting plates for each side.   

I started mocking up some mount ideas by just laser cutting some crazy shapes out of MDF to find an optimal way of fitting them up under the trailer.  As with the suspension and everything else we've attached to the trailer in the past, I mounted it by compressing it between plates and squeezing it up against the trailer frame as opposed to drilling directly into it.

I tried to make the mounting plates fit the angle of the angle iron that attached the rim brakes.  I ended up going with a 3 plate sandwich sort of setup in which I made the back plate holding the angle iron larger, and compressing the trailer frame box tube between that and a second plate to which the motor was attached, and then squeezing the motor between that second plate and a smaller third plate.  The only problem was that because of the asymmetry, I could only fit 2 hex bolts through all 3 mounting plates on the right side as opposed to 4 on the left, but it seems like the 2 fewer bolts does not sacrifice the structural integrity of the mount.  Here's what the final waterjetted aluminum plate configurations looked like:

Left Side Brake Motor

Right Side Brake Motor

The EE team had steadily pushed forward through all of the work with controlling the motors, and you can see the plans of the custom electronics for the brakes in a November blog post.  Here is a video of Rango demonstrating the firmware.

The only major problem once the brakes were mounted was that they were drawing too much current, which was solved by just adding another DC to DC converter to power them.


Although we didn't use the brakes on our way to Providence, they were securely mounted for the duration of the trip.  The mounting held up fine, but the elements did a number on the exposed steel surfaces of the angle iron mounting plates and parts of the motor.  A much needed cleaning and spraying with the rust restore, primer, and black spray paint cleaned everything up pretty nicely, and now the black finish matches the black bar over the wheels on the trailer.