Gravity Vehicle C

User avatar
MTV<=>Operator
Member
Member
Posts: 138
Joined: February 8th, 2019, 12:41 pm
Division: C
State: NY
Location: Dead
Has thanked: 8 times
Been thanked: 4 times

Re: Gravity Vehicle C

Post by MTV<=>Operator » September 9th, 2019, 6:35 pm

SluffAndRuff wrote:
September 9th, 2019, 3:41 pm
windu34 wrote:
September 8th, 2019, 11:09 pm
This brings up an interesting point of discussion: would it be possible to move the center of mass during the run of your vehicle? In the ready to run position, Id estimate wanting about 90% of the mass in the rear, but after the vehicle has descended down the ramp, it is more advantageous to have about 60-70% of the mass in the rear to prevent significant understeer and to aid in uniform braking. Perhaps it is possible to actually have the center of mass MOVE during the run. This could potentially be done near the end of the run (after 6-7 meters have been traveled) as a means of reducing vehicle speed. I envision a simple string wrapping around an axle after a certain distance has passed that moves the center of mass forward.
Food for thought. Id be interested to hear others' perspectives on this.
What's the legality on this, given the phrase in 3.g. "All parts of the Vehicle must move as a whole"?
I think this would be legal because technically the weight is still part of the vehicle, it isn't moving outside of the vehicle or acting as a separate object. I know there was a design in 2012 in which the mass slid from the back to the middle of the vehicle upon launch and remained in the middle for the rest of the run. However, if it significantly increases accuracy scores, could it possibly be worth it to just have the center of mass closer to the middle to begin with in exchange for a slightly greater time?
THHS '21 Builder Cult Member
2017-2018: Mousetrap, Hovercraft, Towers
2018-2019: Mousetrap (8th regional), Boomilever (3rd regional), Wright Stuff
2020 Events/YUSO/regional
Gravity Vehicle/9/5
Detector Building/8/7
Wright Stuff/--/10
Ping Pong Parachute/--/--

User avatar
windu34
Staff Emeritus
Staff Emeritus
Posts: 1364
Joined: April 19th, 2015, 6:37 pm
Division: Grad
State: FL
Location: Gainesville, Florida
Has thanked: 1 time
Been thanked: 22 times

Re: Gravity Vehicle C

Post by windu34 » September 9th, 2019, 6:56 pm

MTV<=>Operator wrote:
September 9th, 2019, 6:35 pm
SluffAndRuff wrote:
September 9th, 2019, 3:41 pm
windu34 wrote:
September 8th, 2019, 11:09 pm
This brings up an interesting point of discussion: would it be possible to move the center of mass during the run of your vehicle? In the ready to run position, Id estimate wanting about 90% of the mass in the rear, but after the vehicle has descended down the ramp, it is more advantageous to have about 60-70% of the mass in the rear to prevent significant understeer and to aid in uniform braking. Perhaps it is possible to actually have the center of mass MOVE during the run. This could potentially be done near the end of the run (after 6-7 meters have been traveled) as a means of reducing vehicle speed. I envision a simple string wrapping around an axle after a certain distance has passed that moves the center of mass forward.
Food for thought. Id be interested to hear others' perspectives on this.
What's the legality on this, given the phrase in 3.g. "All parts of the Vehicle must move as a whole"?
I think this would be legal because technically the weight is still part of the vehicle, it isn't moving outside of the vehicle or acting as a separate object. I know there was a design in 2012 in which the mass slid from the back to the middle of the vehicle upon launch and remained in the middle for the rest of the run. However, if it significantly increases accuracy scores, could it possibly be worth it to just have the center of mass closer to the middle to begin with in exchange for a slightly greater time?
Yeah you could make the sacrifice, but this would be way cooler and could potentially provide a way to slow down before braking if implemented correctly.
Boca Raton Community High School Alumni
Florida Science Olympiad Board of Directors
National Physical Sciences Rules Committee Member
kevin@floridascienceolympiad.org || windu34's Userpage

knightmoves
Member
Member
Posts: 284
Joined: April 26th, 2018, 6:40 pm
Has thanked: 2 times
Been thanked: 11 times

Re: Gravity Vehicle C

Post by knightmoves » September 10th, 2019, 12:35 pm

SluffAndRuff wrote:
September 9th, 2019, 3:41 pm
What's the legality on this, given the phrase in 3.g. "All parts of the Vehicle must move as a whole"?
That's a curious phrase - "move as a whole" isn't very well defined. The next clause talks about no anchors or tethers, so I'd interpret that to mean "everything has to stay with the car" but I wouldn't guarantee that an ES wouldn't interpret it as "no changing mass distribution" without a clarification.

User avatar
windu34
Staff Emeritus
Staff Emeritus
Posts: 1364
Joined: April 19th, 2015, 6:37 pm
Division: Grad
State: FL
Location: Gainesville, Florida
Has thanked: 1 time
Been thanked: 22 times

Re: Gravity Vehicle C

Post by windu34 » September 10th, 2019, 5:51 pm

knightmoves wrote:
September 10th, 2019, 12:35 pm
SluffAndRuff wrote:
September 9th, 2019, 3:41 pm
What's the legality on this, given the phrase in 3.g. "All parts of the Vehicle must move as a whole"?
That's a curious phrase - "move as a whole" isn't very well defined. The next clause talks about no anchors or tethers, so I'd interpret that to mean "everything has to stay with the car" but I wouldn't guarantee that an ES wouldn't interpret it as "no changing mass distribution" without a clarification.
During a run, a wingnut commonly moves within the vehicle. I dont see why other parts (a large mass) couldn't move in a similar fashion.
Boca Raton Community High School Alumni
Florida Science Olympiad Board of Directors
National Physical Sciences Rules Committee Member
kevin@floridascienceolympiad.org || windu34's Userpage

AngelMB
Member
Member
Posts: 16
Joined: June 3rd, 2018, 12:04 pm
Division: C
State: FL
Has thanked: 1 time
Been thanked: 0

Re: Gravity Vehicle C

Post by AngelMB » September 10th, 2019, 6:02 pm

knightmoves wrote:
September 10th, 2019, 12:35 pm
SluffAndRuff wrote:
September 9th, 2019, 3:41 pm
What's the legality on this, given the phrase in 3.g. "All parts of the Vehicle must move as a whole"?
That's a curious phrase - "move as a whole" isn't very well defined. The next clause talks about no anchors or tethers, so I'd interpret that to mean "everything has to stay with the car" but I wouldn't guarantee that an ES wouldn't interpret it as "no changing mass distribution" without a clarification.
I have a hard time believing an ES would see shifting mass as not moving as a whole. As long as no pieces physically fall off the vehicle I can't see how it wouldn't be moving as a whole. This reminds me of the moving dowel arm for some mousetrap vehicles last year, although there were moving parts on some vehicles, they still moved with the MV much like how a shifting weight would move with the GV.
Boca High '20

2020 Events
Boomi, Circuits, Detector, Gravity

Nats Placements 2019
Mission - 1st
Circuits - 7th
Mousetrap - 23rd

User avatar
PM2017
Member
Member
Posts: 522
Joined: January 20th, 2017, 5:02 pm
Division: Grad
State: CA
Location: Enjoying College! :D
Has thanked: 22 times
Been thanked: 6 times

Re: Gravity Vehicle C

Post by PM2017 » September 10th, 2019, 10:20 pm

windu34 wrote:
September 8th, 2019, 11:09 pm
This brings up an interesting point of discussion: would it be possible to move the center of mass during the run of your vehicle? In the ready to run position, Id estimate wanting about 90% of the mass in the rear, but after the vehicle has descended down the ramp, it is more advantageous to have about 60-70% of the mass in the rear to prevent significant understeer and to aid in uniform braking. Perhaps it is possible to actually have the center of mass MOVE during the run. This could potentially be done near the end of the run (after 6-7 meters have been traveled) as a means of reducing vehicle speed. I envision a simple string wrapping around an axle after a certain distance has passed that moves the center of mass forward.
Food for thought. Id be interested to hear others' perspectives on this.
Legality aside, this seems a bit complicated from a technical perspective, because you'd need to have some sort of latch that starts off closed (otherwise the mass would simply slide down when in the ready-to-run). I think it definitely can be done, though. (also I don't know about the legality of this, but could it perhaps hit part of the ramp on the way down that opens the latch? Even if legal, I'm not sure it would be viable because it would take out a large chunk of momentum if not executed very well down, and have to be able to accomodate the dowel, which would likely mean assymetry, in which case any imperfection would mean the car could slightly swerve, causing some major accuracy issues)

The other issue is how much friction the moving mass would have. I wonder if you could build the whole vehicle around a linear slide as a chassis.

IDK how rational this is, but I think that much mass shifting on a vehicle should be pretty scary. OTOH, it would be pretty epic lol.

These thoughts are not fully fleshed out but I'm sort of sleepy, so we'll see what sort of glaring mistakes I've made tomorrow...
West High '19
UC Berkeley '23

Go Bears!

knightmoves
Member
Member
Posts: 284
Joined: April 26th, 2018, 6:40 pm
Has thanked: 2 times
Been thanked: 11 times

Re: Gravity Vehicle C

Post by knightmoves » September 11th, 2019, 7:43 am

PM2017 wrote:
September 10th, 2019, 10:20 pm
Legality aside, this seems a bit complicated from a technical perspective, because you'd need to have some sort of latch that starts off closed (otherwise the mass would simply slide down when in the ready-to-run). I think it definitely can be done, though. (also I don't know about the legality of this, but could it perhaps hit part of the ramp on the way down that opens the latch?
As was mentioned, it was done successfully last time around (and you're right - the pencil released the mass, and the mass hit the vehicle release before it slammed into the rest of the vehicle body). I'd imagine it's also quite easy to mess this up.

knightmoves
Member
Member
Posts: 284
Joined: April 26th, 2018, 6:40 pm
Has thanked: 2 times
Been thanked: 11 times

Re: Gravity Vehicle C

Post by knightmoves » September 11th, 2019, 7:45 am

windu34 wrote:
September 10th, 2019, 5:51 pm
During a run, a wingnut commonly moves within the vehicle. I dont see why other parts (a large mass) couldn't move in a similar fashion.
That's a good point - if the rule was interpreted to mean "no changing mass distribution" then everyone's brakes are illegal, and the whole event becomes a bit silly.

chessbucket
Member
Member
Posts: 23
Joined: September 5th, 2018, 4:34 pm
Has thanked: 0
Been thanked: 0

Re: Gravity Vehicle C

Post by chessbucket » September 11th, 2019, 7:19 pm

I don't know if this is appropriate to put here but I wanted to get other's opinions on this:

Why would they make the distance so long? 12 meters?!?!

This may be unique to my situation but the way our team does building events is the kids do it 99% at home. Most building and testing time is done on weekends and over breaks, which is conveniently when school tends to be closed, so we can't use a hallway or anything like that to test. We don't do scioly as a club after school or during school. Where do you guys test? I've thought about a community center but having to keep transporting builds can 1) increase the chances of something breaking in transport, and 2) constantly changing testing surfaces and locations can introduce confounding variables when ur trying to get sub 5cm accuracy. For MTV, we had a continuous stretch of 8m in the common area of my house, so we always had a constant variable that didn't affect runs differently. with the 12 meter distance this year, it's a different story. I apologize if I sound like I'm whining, venting, and/or ranting but having a constant test surface has always proved to be a must in my experience.
2020: MIT Gravity Vehicle 2nd
2020: MIT Machines 6th

2019: Nationals Mission Possible 2nd
2019: NC Mission Possible 2nd
2019: MIT Mission Possible 4th

2018: NC Mission Possible 1st

nicholasmaurer
Coach
Coach
Posts: 418
Joined: May 19th, 2017, 10:55 am
Division: Grad
State: OH
Location: Solon, OH
Has thanked: 1 time
Been thanked: 20 times

Re: Gravity Vehicle C

Post by nicholasmaurer » September 11th, 2019, 7:27 pm

chessbucket wrote:
September 11th, 2019, 7:19 pm
I don't know if this is appropriate to put here but I wanted to get other's opinions on this:

Why would they make the distance so long? 12 meters?!?!

This may be unique to my situation but the way our team does building events is the kids do it 99% at home. Most building and testing time is done on weekends and over breaks, which is conveniently when school tends to be closed, so we can't use a hallway or anything like that to test. We don't do scioly as a club after school or during school. Where do you guys test? I've thought about a community center but having to keep transporting builds can 1) increase the chances of something breaking in transport, and 2) constantly changing testing surfaces and locations can introduce confounding variables when ur trying to get sub 5cm accuracy. For MTV, we had a continuous stretch of 8m in the common area of my house, so we always had a constant variable that didn't affect runs differently. with the 12 meter distance this year, it's a different story. I apologize if I sound like I'm whining, venting, and/or ranting but having a constant test surface has always proved to be a must in my experience.
I agree a consistent test surface is critical. We usually use our school gym because the wood flooring is typical for what we see at most competitions. But that doesn't sound like a realistic option for you... Does your coach have the ability to request use of the school after hours or over breaks? As you note, even a hallway can be good test track.
Assistant Coach and Alumnus ('14) - Solon High School Science Olympiad
Tournament Director - Northeast Ohio Regional Tournament
Tournament Director - Solon High School Science Olympiad Invitational

Opinions expressed on this site are not official; the only place for official rules changes and FAQs is soinc.org.

Locked

Return to “Gravity Vehicle C”

Who is online

Users browsing this forum: No registered users and 1 guest