You have proven my point.I disagree with limiting batteries at this point. Those of us who have already spent considerable resources should not be required to buy new batteries, motors, or switches because a few people haven't figured out how to make thier device safe. I really doubt simply changing the battery type will prevent someone from designing a dangerous device.
Given the students an option to just purchase the most power available it is creating a dangerous situation and blocking other teams from competing because of money.
Here is calculator so you can play with volts and amps to see that if you limit the number of amps the amount of work that can be done is a fraction of what is possible:
http://www.calcunation.com/calculators/ ... Horsepower
As an example i will use one of our sleds.
7.4 volts and 30 amps gives over .3 a horsepower.
9 volts and 2 amps less than .02 horsepower
That is a magnitude of over 10. Physics limits the possible work, thus safer propeller speeds.
In addition, your school has the money to purchase lipos. lipo chargers and everything else but they can't spring for $20 for rechargeable batteries a battery case and a connector. I would have a talk with the budget people.
Or is your point, since you have already purchased the items the event can't be changed because it would inconvenience you next year?
I really don't think you understand this event. The goal is to make an unsafe device. Remember, the fastest most powerful device wins.The rules already prohibit unsafe devices. Now we just need to consistantly enforce them.
By your logic no one can do this event. There is no way to guarantee that an accident does not happen. By design the students have to put something in front of an object that can generate more than 2 times the force needed for low earth orbit. That same object has rotating blades that can shred clothes and cut deep into the tissue. There is no way to make the event safe. This year by design, it is unsafe.Unless the kids have figured out a way to insure they will not contact the blades, don't let them run.
However, i do like your idea of making it a time to distance event.