Review

Sorry it’s been so long since we wrote. When we got home from competition we were in the midst of midterms and fabricating term long projects. Now with graduation done we can sit back and fill you in.

Feel free to read the article the valley news wrote about us at competition:

http://www.vnews.com/Dartmouth-Formula-Racing-1756215

and also this article by the Concord Monitor:

http://www.concordmonitor.com/Formula-Hybrid-racing-NH-Motor-Speedway-Loudon-NH-1952842

Competition was a long 4 days but we learned a lot from the other teams, worked hard, and got the car working by the last day for the endurance competition. It took us a little over three hours to get through electrical inspection though and by the time we were done we didn’t get through Mechanical in time to race. We would not have passed mechanical inspection anyway because our cockpit was too small. We were proud of the work we did and two weeks later Thomas and I got together and took the car for a spin behind Thayer, here’s a video!

And another!

The thunk you hear at the end of the first video is Thomas hitting a pothole, but she survived thanks to a killer skid plate. She drives beautifully and we can’t wait to get her running on gas and drive her some more. Issues still to tackle are a reliable hybrid controller and charging the batteries in an efficient way.

We just want to say thank you to all our sponsors for believing in us and helping us complete a working car. We may not have raced at competition but the future looks good for a professionally built, reliable, and thrilling to drive racecar this summer and next year.

2 Weeks to Go

It has been a wicked long time since we wrote. Basically we have two weeks till competition and we are working furiously to get the car put together. We now have a drivetrain assembled and we are working on the wiring so we can do a test run! Here are some pics from the past month

 

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These are the tabs to hold our motor and bearing plates to the chassis

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Just starting to line things up within the chassis over spring break

 

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Figuring out the firewall, headrest, and GLVS enclosure

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Before building a racecar one must complete the SolidWorks tutorials

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Out with the old pedal package, in with the new!

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Our welds are getting better!

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This was at the beginning of spring break, we’ve come a long way since then, still a long way to go

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Watch out VR3, Nadav is coming your way…

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Trying out the rear suspension for the first time

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The beginnings of a beautiful sprocket mount

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The things we do for welding

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Rolling chassis!

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Battery box is in!

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The drivetrain is being assembled

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Drivetrain is in and ready to go!

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Our own Jake H. grinding away

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A labor of love, the electric drivetrain

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A wiring nightmare, don’t worry we are cleaning it up!

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The coveralls are necessary

 

Overall we’ve got a ton to do. We’ve got a drivetrain that spins and all the chains are sized but we need to get everything hooked up electrically to make the wheels spin. The accumulators are now mounted in the chassis and being wired. GLVS is being wired up using many, many Deutsch connectors at the moment. We will post again when we have the wheels spinning!

Spring Break Part I

Hi There,

It’s been a while since we’ve updated you. It’s spring break here at Dartmouth but DFR is not taking a break, in fact we’re just gearing up! We’ve been doing lots of work fabricating our designs and changing them along the way of course. We just submitted our last 3 big forms to Formula Hybrid last night so we’re off to the races! Here are a few photos from our days to give you an idea of what we’ve been up to:

This was at about 4AM after we finished prepping the chassis for some final welds! Team Leaders unite

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This was driving the chassis to Maine to be welded by our friend Aaron who works for Soleras LTD.

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At Aaron’s house we tack welded the battery box but soon found that the mig torch was not so good in all the tight corners we have. image3

Thanks Marden’s for this great hanging chair! New addition to the lab and absolutely crucialimage4

We made the engine mounts and the engine is now sitting in the chassis without straps!image5

More welding pic’s at Aaron’s house. This is one of our battery cages.image6

Lastly a nice picture of our seat belt position! image7

That’s all for now! In the days to come we will have made the electric powertrain mounts and finished our welding!

Full Control Pipeline

We’ve got it! We’ve got a full control pipeline! Data comes up from the vehicle components like the engine to our controller and we are able to control the motor based on that data! This is a huge deal for it means we have hybrid control in our vehicle working and we can’t wait to test it in the car. What we have running in this video is a very simple linear control algorithm for testing purposes that demands a speed from the motor. In the car we will demand a torque from it instead of speed and have a much more complex state machine enabled so that the car is better optimized for the endurance event and has shut down procedures.

On another note Alex and Khet made some rear suspension tabs today so we will hopefully have that done by March 11th and start rolling things along. Pictures to come.

 

If you want to know more about the BAMOCAR or Emrax 228 please email us at dartmouth.formula.racing@dartmouth.edu (we’ve learned the scaling is quite tricky on the BAMOCAR!)

Always have a Shut Down Button

This weekend during build day we got a ton done! Battery was put together, we cleaned the lab, the controls group tested their code, but most importantly we got the engine running! Here are a few videos for your enjoyment!

As you can see, Andrew (our Internal Combustion Engine lead) was very happy 🙂

Here we decided to try out the throttle and you’ll see how it went…

 

Hence the message ALWAYS have a shut down button on your bench tests! Overall an exciting day and with spring break coming up we’ve got a TON going on! More for you to come.

 

We CAN Control the Motor!

See the pun there? As of tonight we have successfully controlled our Emrax 228 motor with CAN signals coming from our hybrid controller! This is huge because it shows our full downwards data pipeline is working. Next step tomorrow is to hook up the web app so we can display this data in real time and meet with our sponsors SunEdison to show them our work!

P.S. Today we also welded some frame members in the chassis to start mounting the motor and engine!

Technical notes:

  • Battery pack we used is 140.2 Volts nominal, controlled with Orion BMS.
  • The BMS and motor controller (BAMOCAR D3) are powered by 12V power supplies limited to 3 and 10 amps respectively.
  • We had to create a precharge circuit that hooks the battery pack to the BAMOCAR. If you hook them up directly you will get a huge surge of current through the controller that can destroy components, the pre charge circuit charges the BAMOCAR gradually. Watch out for the internal circuitry of the BAMOCAR when designing this.
  • If you have questions about programming the BAMOCAR software (NDrive) please contact us at dartmouth.formula.racing@dartmouth.edu. It’s too complicated to put here in this post.
  • The SunEdison board we used to do this does not have CAN ports so we used an Arduino CAN shield from Sparkfun and some RS-485 shields to communicate with the processor through some UARTS.
  • PLEASE do not try this without high voltage training. Notice our safety procedures, clear directions, and clear exit path in case things went wicked wrong.
  • Also note the big red button, ALWAYS have a safety shut down for bench tests!