Mousetrap Vehicle C

[beaverkid]

So on the subject of launching the cup instead of pushing it:

Would it be legal to just load a rubber band prior to the run and start the run by releasing it? From what I've seen in the rules we're only allowed to use power from the mousetraps to contribute to propulsion but this wouldn't be propulsion.

If not, would we somehow have to use the mousetrap's energy to launch the cup?

I was curious about whether cup launching was legal as you probably saw in my previous posts.

One of my team members got in touch with the nationals car event supervisor, and he stated that it is illegal to launch the cup from the start line and then reverse to the target point. I would strongly advise against doing this at states and definitely not at nats, unless some clarification is made.

I think at best, it would be a violation for not pushing the cup forward. At worst, it would be violating the spirit of the rule and getting maybe only participation points.

[PM2017]

(Currently using banebots, but those have a lot of inertia.)

What size? 2 7/8” are pretty light.

Honestly I probably don't know what I'm talking about... Sorry.

[windu34]

This is in no way an official nationals post nor do I represent the opinions of the National Event Supervisor for this event:

I recently supervised a regional in Florida where a team successfully used a mousetrap to shoot the cup past the 3 meter mark and proceed to reverse to the target point. I deemed this action legal and within the rules and they were awarded first place.
Using any other means of energy to launch the cup other than one of the two mousetraps is illegal.
HOWEVER
While there is nothing explicitly forbidding this in the rules, this strategy has 2 barriers that must be overcome-
1.) Spirit of the Rules: Point of the event is to move forward and reverse - This can be overcome by moving any quantity of distance forward, then launching the cup, and then reversing to the target point. For example, moving 10cm forward, then launching the cup, then reversing to the target point.
2.) "The cup must remain in contact with the ground at all times": You must be able to launch the cup in a way in which it remains in contact with the ground at all times. If you can find a way to do this consistently, it may be worthwhile. If you cannot, I would be wary of attempting such a strategy at any level of competition.

In my opinion, I do believe it is possible to successfully accomplish this and it will give a huge advantage - especially when it comes to the national level. This is a very risky strategy, however, and you should not proceed to compete with this strategy without being extremely confident your device successfully overcomes the aforementioned barriers as well as any other challenges this strategy comes with.

[Rêveur]

This is in no way an official nationals post nor do I represent the opinions of the National Event Supervisor for this event:

I recently supervised a regional in Florida where a team successfully used a mousetrap to shoot the cup past the 3 meter mark and proceed to reverse to the target point. I deemed this action legal and within the rules and they were awarded first place.
Using any other means of energy to launch the cup other than one of the two mousetraps is illegal.
HOWEVER
While there is nothing explicitly forbidding this in the rules, this strategy has 2 barriers that must be overcome-
1.) Spirit of the Rules: Point of the event is to move forward and reverse - This can be overcome by moving any quantity of distance forward, then launching the cup, and then reversing to the target point. For example, moving 10cm forward, then launching the cup, then reversing to the target point.
2.) "The cup must remain in contact with the ground at all times": You must be able to launch the cup in a way in which it remains in contact with the ground at all times. If you can find a way to do this consistently, it may be worthwhile. If you cannot, I would be wary of attempting such a strategy at any level of competition.

In my opinion, I do believe it is possible to successfully accomplish this and it will give a huge advantage - especially when it comes to the national level. This is a very risky strategy, however, and you should not proceed to compete with this strategy without being extremely confident your device successfully overcomes the aforementioned barriers as well as any other challenges this strategy comes with.

What would be the benefits of such a strategy?
To me it seems only to be a time advantage, though you might lose even that with the energy you have to expend from the mousetraps the launch the cup

[rafaelnadal]

how would two different axle sizes affect the drive? im thinking of making the winding axle from 1/4" to 1/8" but keeping the other axle 1/4" because i dont have time to order more 1/8" bearings

also can someone direct me to 1/4" carbon fiber rods please?

currently i'm using wooden dowels for my axles, would they have a lot of friction against the bearings? my car seems to be slow (cant even go full distance but already ~20 seconds), and i have banebots, 3d print/carbon fiber chassis, which should go fairly fast


frame length: 47 cm
lever arm length: 53 cm
2 7/8" banebots

[windu34]

What would be the benefits of such a strategy?
To me it seems only to be a time advantage, though you might lose even that with the energy you have to expend from the mousetraps the launch the cup

The team competing at my regional had a time of less than 4 seconds because they launched the cup and their device was not nearly as well built nor optimized as it could be. The fact that you eliminate an entire 6 meters from your total travel distance as well as the change in direction makes a huge difference in terms of speed and you can also be more accurate. Additionally your lever arm can exert a higher impulse (force over time) because the travel distance is so much smaller.

[DarthBuilder]

How would you launch a cup?

[Chameleon02]

I have been hearing whispers in my state about a car that can do 6 seconds there and back with <2cm accuracy so RIP us.

[Rêveur]

What would be the benefits of such a strategy?
To me it seems only to be a time advantage, though you might lose even that with the energy you have to expend from the mousetraps the launch the cup

The team competing at my regional had a time of less than 4 seconds because they launched the cup and their device was not nearly as well built nor optimized as it could be. The fact that you eliminate an entire 6 meters from your total travel distance as well as the change in direction makes a huge difference in terms of speed and you can also be more accurate. Additionally your lever arm can exert a higher impulse (force over time) because the travel distance is so much smaller.

I was under the impression that you would not be able to eliminate the change in direction, as that would violate the spirit of the event.

[PM2017]

What would be the benefits of such a strategy?
To me it seems only to be a time advantage, though you might lose even that with the energy you have to expend from the mousetraps the launch the cup

The team competing at my regional had a time of less than 4 seconds because they launched the cup and their device was not nearly as well built nor optimized as it could be. The fact that you eliminate an entire 6 meters from your total travel distance as well as the change in direction makes a huge difference in terms of speed and you can also be more accurate. Additionally your lever arm can exert a higher impulse (force over time) because the travel distance is so much smaller.

I was under the impression that you would not be able to eliminate the change in direction, as that would violate the spirit of the event.

Well you can go forward like 10 cm, and then reverse...