Electric Vehicle C

[windu34]

New user to this forum. Working to get ready to run an event at an invitational.

Can anyone provide info on how to economically buy or construct a photo-gate system (including related software that would work with a laptop or tablet) suitable for use with this event? The ones I see online are close to $200 with tax and shipping and that's not in the budget especially since I'll need 2 of them in order to run 2 simultaneous tracks.

Posted this in Hovercraft too, but thought maybe I'd get a better response over here.

Thanks for any help.

I built one myself at the beginning of the year with a few laser modules, photo resistors, and an Arduino. Takes a little coding experience and knowledge of external interrupts to do it well. To be honest, photogates are really not important for EV this year with the reduced importance of time. Timers should be more than sufficient for every competition except maybe nationals so I wouldn't worry about it.

[GoldDigger]

Hey Private Wang Fire,

How did you do the math? Lol I want to know how you got that number:

"I did some math and it seems as if your angle needs to be <.5 the adjust between even the regional distances."

Also, how do I quote previous replies?

[Private Wang Fire]

Hey Private Wang Fire,

How did you do the math? Lol I want to know how you got that number:

"I did some math and it seems as if your angle needs to be <.5 the adjust between even the regional distances."

Also, how do I quote previous replies?

Umm it's some turning radius/circle chord thing. I solved for the radius from an arc with the length of the chord as the distance and the bonus height as the distance from the chord to the circle, then put that into the formula for turning radius with a wheelbase of 0.60m and solved for the angle.

And quote using the "quote previous" button on the post or the quote thingy next to the underline when you're writing the post lol.

[GoldDigger]

Interesting I got <0.25 degrees for every .5 meter increment...

[windu34]

Interesting I got <0.25 degrees for every .5 meter increment...

Yeah I got about the same

[GoldDigger]

I have recently hit a road block with my fixed steering design. The inner circles of my ball bearings for my front wheels wiggle side to side about .1mm. I am using premium skate board bearings. The wiggle room translates to 10+ cm of inaccuracy. I'm stuck and might have to switch my Ackerman steering to a setup where I would pivot my entire axis instead. Do you guys have some advice? How did people get past this problem?

[windu34]

I have recently hit a road block with my fixed steering design. The inner circles of my ball bearings for my front wheels wiggle side to side about .1mm. I am using premium skate board bearings. The wiggle room translates to 10+ cm of inaccuracy. I'm stuck and might have to switch my Ackerman steering to a setup where I would pivot my entire axis instead. Do you guys have some advice? How did people get past this problem?

Also, thanks for answering my previous question Bazinga!

Ackerman steering has too many joints thus increasing uncertainty of your measurement. Id recommend switching to a pivot.

[Unome]

So apparently Run Time is measured to the nearest second this year? (per 5.k)

Misread the rule, nvm. I took "in seconds" to mean "without decimals," when the rest of the statement says "to the precision of the timing devices."

Random question: does a team attempting the bonus but failing count for anything? (assuming they complete the run as normal, somehow)

[windu34]

So apparently Run Time is measured to the nearest second this year? (per 5.k)

Misread the rule, nvm. I took "in seconds" to mean "without decimals," when the rest of the statement says "to the precision of the timing devices."

Random question: does a team attempting the bonus but failing count for anything? (assuming they complete the run as normal, somehow)

I would assume it counts as a normal run (no bonus)

[Unome]

So apparently Run Time is measured to the nearest second this year? (per 5.k)

Misread the rule, nvm. I took "in seconds" to mean "without decimals," when the rest of the statement says "to the precision of the timing devices."

Random question: does a team attempting the bonus but failing count for anything? (assuming they complete the run as normal, somehow)

I would assume it counts as a normal run (no bonus)

Ok; I was wondering because I saw that the national spreadsheet asks for whether or not a team completed the bonus, which seemed repetitive. I guess it must just be to deal with an ES entering in "0" for teams that didn't do the bonus, thus effectively boosting their scores. Technically neither column seems to be required in order for the spreadsheet to function, but if an ES is going to enter all of those zeroes, they'll probably try to enter info for all teams in all columns anyway.