Supermileage Vehicle

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rcman50166
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Sat May 01, 2010 11:24 am

Labtecpower wrote:Belts have a higher efficiency compared to chains. Chains have an efficiency
up to 94%, while belts are as efficient as 99%. Definately something to
keep in mind in my opinion.
From what I read it is dependant on the situation or application. Belts become more efficient at higher RPM's and higher torque. But belts also stretch and it length cannot be changed once made. Chains you simply take out links.
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D_Hall
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Sat May 01, 2010 11:57 am

rcman50166 wrote:Laval...Grrr.. They :sign10: all over the competition every year. They have seen over 3000 mpg before. They are essentially the team to beat. However rumors through the grape vine say that a team will be there with a car with an economy of 4200 mpg. :shock: Our school will get there... some day :thumbleft:
Question: Obviously you're not going to know everything they're doing, but.... Well, let me put it this way.... Way back in the dark ages I used to be involved in electric vehicle competitions ( hint ). And one thing we saw.... It was all about the bucks. The school with the most money to spend (or better equipped machine shop...which is really the same thing) was the school that won. The school with the least money to spend lost. Sure, there was a bit of shuffling as luck/fate intervened with parts failures or crashes, but as a general rule you could rank the cars in advance by how much money was spent on them....and that's the way they finished the race.



edit: To answer the obvious question: How did everybody know how much everybody else was spending? Components. Everybody researched batteries. Everybody knew what was available and what it cost. Everybody bought the best they could afford, but not everybody could afford the best (in fact, only one school could). Everybody researched motors. Everybody knew what was available and what it cost.... Blah blah blah... For every major component. Add it all up and you had a pretty good idea of what was spent on a car.
Last edited by D_Hall on Sat May 01, 2010 12:04 pm, edited 2 times in total.
Simulation geek (GGDT / HGDT) and designer of Vera.
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Labtecpower
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Sat May 01, 2010 12:22 pm

The information I have read was about using belts as a substitute for chains on bicycles. The belts used are made out of carbon fiber, and have zero stretch and last longer as a conventional chain.
They are already commercially used by the german company Rohloff, with successfull testing.
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rcman50166
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Sat May 01, 2010 6:48 pm

D_Hall wrote: And one thing we saw.... It was all about the bucks. The school with the most money to spend (or better equipped machine shop...which is really the same thing) was the school that won. The school with the least money to spend lost.
Absolutely 100% true. This year we have invested about $40,000 into the project. These first place cars are easily 100k cars. Our machine shop is the saddest you'd ever see. A manual bridgeport milling machine and lathe are about the most complicated machines we have.
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rcman50166
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Tue May 11, 2010 8:40 pm

Thought I might update the thread, it's been a while.

The car it pretty much done as far as mechanical systems go. The shell is going back to our sponsor tomorrow for the final assembly and paint. The next time you see the car, it will be yellow, and have pants.

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So our car is supposed to have an electronic throttle. The idea behind that is to eliminate the human variable all together. The only things our driver will actually be able to control is speed, turning, and braking. The rate at which he/she throttles is electronically controlled, so is the starter motor. We have been working over the weekend to get the prototype working and as of right now, it is fully operational.

Pictures:

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And here's a video of it working.
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Technician1002
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Tue May 11, 2010 9:25 pm

But belts also stretch and it length cannot be changed once made.
VW Beetles fan belt was of this configuration where the distance between pulleys could not be changed. Belt tension was adjusted by one of the pulley's was a split pully and the width was adjusted by moving shims from inside to outside and back as needed.

On the vehicle build, It's looking fantastic. I'm glad the electronics is working. Fly by wire can help save fuel as the control is dedicated to engine management while the driver is distracted with navigation.

I like the view of the fuel tank. It shows how little fuel you carry onboad. This is part of the reason for little cooling as mentioned earlier, little energy is used.
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spudtyrrant
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Tue May 11, 2010 10:31 pm

Ha-ha my year long reconnaissance plan worked, i knew you would eventually post here lol :lol:
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rcman50166
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Tue May 11, 2010 10:59 pm

spudtyrrant wrote:Ha-ha my year long reconnaissance plan worked, i knew you would eventually post here lol :lol:
lol we're not using new technology yet. That's next year. :roll:
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Technician1002
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Tue May 11, 2010 11:42 pm

Is there any plans to cover the spokes to reduce windage?
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rcman50166
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Tue May 11, 2010 11:47 pm

Yes, the pants I was referring to are skirts that come down the side of the wheels. Like shown:

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rcman50166
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Thu May 20, 2010 6:02 pm

Sneak Peak...

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Forgive me photo gods for I have sinned.
(ISO = 1600 on a point and shoot)
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