Electric Vehicle C

MontyBuilder
Member
Member
Posts: 14
Joined: May 14th, 2009, 3:29 pm
Division: B
State: NJ
Location: with betsy
Has thanked: 0
Been thanked: 0

Re: Electric Vehicle C

Post by MontyBuilder » May 16th, 2009, 10:27 am

andrewwski wrote:It just means that you're connecting that pin to ground (negative). Doesn't matter where you physically connect it to, as it's going to be a negative-ground system. Theoretically you don't need that wire though as you only need to break the circuit.
so it isn't necessary
i can take it out
hb
One Team
One Dream
Whipped Cream

Dark Sabre
Admin Emeritus
Admin Emeritus
Posts: 705
Joined: January 4th, 2004, 5:53 pm
Division: Grad
State: KY
Location: Louisville, KY
Has thanked: 0
Been thanked: 0
Contact:

Re: Electric Vehicle C

Post by Dark Sabre » May 16th, 2009, 10:51 am

Right, you don't actually need it unless you are wanting to try the eddy-current brake.

"A simple application of Lenz's law can be seen in the eddy current brake. A simple eddy current brake can be easily made by connecting the two terminals of a DC motor."

The motor stopping and the wingnut jamming against the switch will probably be enough, but try it the other way if it isn't.

MontyBuilder
Member
Member
Posts: 14
Joined: May 14th, 2009, 3:29 pm
Division: B
State: NJ
Location: with betsy
Has thanked: 0
Been thanked: 0

Re: Electric Vehicle C

Post by MontyBuilder » May 16th, 2009, 6:09 pm

i thought exactly the same thing

thanks that's great

ive designed it on the paper,
and I've found the best way to fit it on a car

the only other thing to do before starting to build is trying to equalize the mass on both sides of the car so it goes striaght, is that actually necessary since the car is going at a very low velocity?
One Team
One Dream
Whipped Cream

MontyBuilder
Member
Member
Posts: 14
Joined: May 14th, 2009, 3:29 pm
Division: B
State: NJ
Location: with betsy
Has thanked: 0
Been thanked: 0

Re: Electric Vehicle C

Post by MontyBuilder » May 16th, 2009, 6:09 pm

oh
how much $ is a momentary switch?
One Team
One Dream
Whipped Cream

andrewwski
Admin Emeritus
Admin Emeritus
Posts: 954
Joined: January 12th, 2007, 7:36 pm
Division: Grad
Has thanked: 0
Been thanked: 11 times

Re: Electric Vehicle C

Post by andrewwski » May 16th, 2009, 6:41 pm

Probably $3-$5 retail.

MontyBuilder
Member
Member
Posts: 14
Joined: May 14th, 2009, 3:29 pm
Division: B
State: NJ
Location: with betsy
Has thanked: 0
Been thanked: 0

Re: Electric Vehicle C

Post by MontyBuilder » May 17th, 2009, 9:42 am

what's wrong with using one battery instead of 4?

if you have an extremely fast motor, isn't the slower the better because your results are more consistent and easier to calculate?

after those, im done with questions so i can stop bugging everyone
One Team
One Dream
Whipped Cream

gh
Admin Emeritus
Admin Emeritus
Posts: 323
Joined: October 22nd, 2003, 5:47 pm
Division: Grad
State: NY
Location: CA
Has thanked: 0
Been thanked: 0
Contact:

Re: Electric Vehicle C

Post by gh » May 19th, 2009, 5:47 pm

There is no advantage. Use what power source you should use/want to use for your motors. I guess battery voltages vary between cells. If you use more than one, they end up averaging out the voltage variation. Still, use a battery configuration that suits your motors.

If you use electronics, you may be required to provide a certain voltage to the circuitry, and that may not be fulfilled by a single alkaline cell.

In general, motors should be geared down to provide higher torque and lower speeds.
This will let them negotiate changes in friction, etc. so that acceleration remains similar across different conditions.

Aim for 45 second runs; if your absolute time error is constant no matter how long the run takes, then having a long run reduces relative error (which is what your score is based on).
“Rather fail with honor than succeed by fraud.” —Sophocles
If you are looking to give help or get help:
[wiki][/wiki] > Forum post > > PM > Email
Don't forget the Image Gallery, the , and the list of Exalted User medals.

User avatar
andrew418
Member
Member
Posts: 97
Joined: April 1st, 2008, 2:56 pm
Division: Grad
State: TX
Location: LASA, Austin, Texas
Has thanked: 0
Been thanked: 0

Re: Electric Vehicle C

Post by andrew418 » May 25th, 2009, 12:41 pm

Hey guys

I was going to post some pictures of my EV, but it looks like someone did it for me here:

http://gallery.scioly.org/details.php?image_id=1304
http://gallery.scioly.org/details.php?image_id=1306
http://gallery.scioly.org/details.php?image_id=1305
http://gallery.scioly.org/details.php?image_id=1286
http://gallery.scioly.org/details.php?image_id=1285
http://gallery.scioly.org/details.php?image_id=1283

If you have any questions or want a better pictures of anything, just let me know, and I'll see what I can do ;)

It didn't do all that well at nationals, I made some pretty stupid operator error mistakes, but what can you say...
LASA 2009; UC Berkeley 2013

fullofit
Member
Member
Posts: 8
Joined: May 27th, 2009, 12:07 pm
Division: C
State: CA
Location: Mira Loma
Has thanked: 0
Been thanked: 0

Re: Electric Vehicle C

Post by fullofit » May 27th, 2009, 12:38 pm

I don't like to complain about how events are run because I know how hard the volunteers work to make SO Nationals happen, so I will call this a suggestion rather then a complaint. If you are going to run an event you should carefully look over the rules. In this case the rules specifically state that if the floor has boards running in one direction, the track shoudl be set up across the boards not parrallel to them. If we had known that we were going to have to deal with large cracks parallel to the track we could have designed our EV to deal with that issue but the rules told us that we would not have to deal with that issue. It would have been easy to run the scrambler and EV tracks across the boards rather then parrallel to them. Perhaps next time these events are run the coordinator can take the track surface into account.

Dark Sabre
Admin Emeritus
Admin Emeritus
Posts: 705
Joined: January 4th, 2004, 5:53 pm
Division: Grad
State: KY
Location: Louisville, KY
Has thanked: 0
Been thanked: 0
Contact:

Re: Electric Vehicle C

Post by Dark Sabre » May 27th, 2009, 1:50 pm

fullofit wrote:I don't like to complain about how events are run because I know how hard the volunteers work to make SO Nationals happen, so I will call this a suggestion rather then a complaint. If you are going to run an event you should carefully look over the rules. In this case the rules specifically state that if the floor has boards running in one direction, the track shoudl be set up across the boards not parrallel to them. If we had known that we were going to have to deal with large cracks parallel to the track we could have designed our EV to deal with that issue but the rules told us that we would not have to deal with that issue. It would have been easy to run the scrambler and EV tracks across the boards rather then parrallel to them. Perhaps next time these events are run the coordinator can take the track surface into account.
Could you point to the section and number where it specifies the direction of the track, I'm not seeing it :?

Post Reply

Return to “2009 Build Events”

Who is online

Users browsing this forum: No registered users and 1 guest