Wind Power B/C

[sunvenu]

With a resistor in (2 ten ohm resistors connected in parallel), we are seeing almost a drop of 5 times on the voltage that the multimeter reads.. Is this expected?

[chalker]

With a resistor in (2 ten ohm resistors connected in parallel), we are seeing almost a drop of 5 times on the voltage that the multimeter reads.. Is this expected?

Yes. But keep in mind that the absolute value of the voltage isn't really important. Scoring will be relative to all the other teams that compete at a specific tournament.

[embokim]

anyone know a good place to get this wind turbine?
Thanks.

[chalker]

anyone know a good place to get this wind turbine?
Thanks.

What do you mean by 'wind turbine'? You are supposed to make your own blade assembly, and can either make the testing apparatus or buy it from Ward's Science.

[soyuppy]

is it possible that CD motor can get busted due to constant and repeated rotation both clockwise and counterclockwise? With load in the system, I'm seeing voltage reading all over the place. It drop as the blade spin faster.

Do you have a resistor in the circuit as specified in the rules? Wild voltage readings is one indication that you might not have one.

yes, 2x10 Ohm in parallel. register on meter as 5.1 Ohm

[Mistah Eye]

I am confused by the functional modification. If I buy a pre-made pin wheel that obviously can't attach to the motor as is, is it a functional modification to glue it to a CD since that would allow it to now be used? How much of a modification must happen? If I buy a kit, put it together with the specs given, then drill a hole in it, is that enough of a modification? Any help would be appreciated. Thanks.

[chalker]

I am confused by the functional modification. If I buy a pre-made pin wheel that obviously can't attach to the motor as is, is it a functional modification to glue it to a CD since that would allow it to now be used? How much of a modification must happen? If I buy a kit, put it together with the specs given, then drill a hole in it, is that enough of a modification? Any help would be appreciated. Thanks.

As always, this isn't the place for official comments or clarifications - soinc.org is for that. That said, we've used the 'functional modification' language for several years in the Robot events. The general guidance is it's something that without would cause the device to not work or work substantially differently. In my personal lingo, a modification is either FUNCTIONAL, or COSMETIC. Hence, generally doing something like drilling a hole in something is usually going to fall into the cosmetic category. At the end of the day, it's up to the individual event supervisor. Thus I always recommend erring on the safe side of what a supervisor might think is functional.

[Mistah Eye]

I am confused by the functional modification. If I buy a pre-made pin wheel that obviously can't attach to the motor as is, is it a functional modification to glue it to a CD since that would allow it to now be used? How much of a modification must happen? If I buy a kit, put it together with the specs given, then drill a hole in it, is that enough of a modification? Any help would be appreciated. Thanks.

As always, this isn't the place for official comments or clarifications - soinc.org is for that. That said, we've used the 'functional modification' language for several years in the Robot events. The general guidance is it's something that without would cause the device to not work or work substantially differently. In my personal lingo, a modification is either FUNCTIONAL, or COSMETIC. Hence, generally doing something like drilling a hole in something is usually going to fall into the cosmetic category. At the end of the day, it's up to the individual event supervisor. Thus I always recommend erring on the safe side of what a supervisor might think is functional.

I understand that nothing here is official. According to the Wind Power rule 3.e. "Commercial kits or third party designs may be used, but must have at least one functional modification, defined as a modification such that the lack of it will result in the assembly working differently or not working." In your opinion, would adding a pinwheel or model's propeller to a CD, something that must happen to every blade assembly, be considered a functional modification since the turbine could not function in this event without the connection?

Altering a blade's angle, putting holes in a blade to lighten it, sanding a blade, shortening a blade and curving a blade all seem to be modifications, but none of these modifications alter the general function of the blades, and none of these modifications, unless to great extremes, seem to enable or disable the function of the blades. However, the blades could work "differently" since they may or may not cause the assembly to rotate faster. If I bring two almost identical designs, with one having holes, and show the supervisor that the holy one spins faster, don't the two designs "work differently"?

I have looked for answers on soinc.org, and these question have not been officially addressed. I am not sure where to go to get answers to them. Thanks for your reply, Chalker. I appreciate you volunteering your time to Science Olympiad.

[chalker]

In your opinion, would adding a pinwheel or model's propeller to a CD, something that must happen to every blade assembly, be considered a functional modification since the turbine could not function in this event without the connection?

In my opinion, no.

Altering a blade's angle, putting holes in a blade to lighten it, sanding a blade, shortening a blade and curving a blade all seem to be modifications, but none of these modifications alter the general function of the blades, and none of these modifications, unless to great extremes, seem to enable or disable the function of the blades. However, the blades could work "differently" since they may or may not cause the assembly to rotate faster. If I bring two almost identical designs, with one having holes, and show the supervisor that the holy one spins faster, don't the two designs "work differently"?

Perhaps. Again, the key here is to convince the individual event supervisor. If you are going to those extremes, why not just design your own?

[dfretz]

The example in the spec book is very confusing. It makes it look like modifications to the CD are allowed, but then it says they arent. The CD doesn't even seem to be part of the diagram at all.