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Re: Hovercraft B/C

Posted: October 16th, 2016, 1:34 am
by daycd
Is there a range for the target times specified? For example, what kind of top speed will be required to match the target time?

Re: Hovercraft B/C

Posted: October 16th, 2016, 4:08 am
by SPP SciO
daycd wrote:Is there a range for the target times specified? For example, what kind of top speed will be required to match the target time?
Rule 5.f - anywhere between 5.0 - 25.0 seconds, revealed after impound. I was initially surprised; I was expecting some language along the lines of "in 5-second intervals at Regionals, 1 second intervals at State, 0.1 second at Nationals" but there is no such wording in the rules. But, unlike say Scrambler, you have several chances to "fine tune" your runs to get even closer, if you've got some bizarre target time like 11.111 seconds.
chalker wrote:
meierfra wrote:How is Hovercraft, as an event, supposed to be run? When I saw that it was online scheduled, I first thought you would sign up for a time to run your vehicle and then take the test immediately following, like our State did MagLev last time. But now I just saw the Event Logistics Chart and they recommend signing up for time periods. Is it supposed to be run more like Wind Power, only that you can sign up for a testing period? So, there are no spectators allowed?
It's really up to the individual event supervisor. Both techniques are possible and likely to be used at tournaments this year.
So this is something I'm concerned about - Our Regional schedule was posted and it has Hovercraft scheduled like other build events, a time slot is selected. However, at Regionals, unlike State or National, it's common to see 2+ teams from the same school. For other events, this isn't a problem, because all teams from the same school would test in the same block. But with this format, as it stands now, it seems likely that School Team X could sign up for an early time slot, and the students would be able to discuss the written test with the members of School Team Y, who signed up for a later time slot.

Re: Hovercraft B/C

Posted: October 21st, 2016, 6:49 pm
by Patrick Yepes
Quick question... Coaches are not allowed to help build the hovercrafts for the students. That said, can the coaches machine special propellers out of plastic that the students then have to bend to the desired angle? I ask because I'm not liking the selection of propellers off the shelf. I don't see much difference in buying a propeller versus machining one. Anyone got an answer? Thank you!

Re: Hovercraft B/C

Posted: October 21st, 2016, 7:19 pm
by Unome
Patrick Yepes wrote:Quick question... Coaches are not allowed to help build the hovercrafts for the students. That said, can the coaches machine special propellers out of plastic that the students then have to bend to the desired angle? I ask because I'm not liking the selection of propellers off the shelf. I don't see much difference in buying a propeller versus machining one. Anyone got an answer? Thank you!
Most likely this depends on the actual safety hazard involved. Some people say "if it's not illegal for minors, students should do it," while others might say the opposite. Regardless, the students should probably be designing the propeller.

Re: Hovercraft B/C

Posted: October 21st, 2016, 8:11 pm
by Patrick Yepes
Unome wrote:
Patrick Yepes wrote:Quick question... Coaches are not allowed to help build the hovercrafts for the students. That said, can the coaches machine special propellers out of plastic that the students then have to bend to the desired angle? I ask because I'm not liking the selection of propellers off the shelf. I don't see much difference in buying a propeller versus machining one. Anyone got an answer? Thank you!
Most likely this depends on the actual safety hazard involved. Some people say "if it's not illegal for minors, students should do it," while others might say the opposite. Regardless, the students should probably be designing the propeller.
I appreciate the timely response but do you think 6th - 8th graders have the ability to design and program (much less run a CNC machine tool) a propeller?

Re: Hovercraft B/C

Posted: October 21st, 2016, 8:51 pm
by windu34
Patrick Yepes wrote:
Unome wrote:
Patrick Yepes wrote:Quick question... Coaches are not allowed to help build the hovercrafts for the students. That said, can the coaches machine special propellers out of plastic that the students then have to bend to the desired angle? I ask because I'm not liking the selection of propellers off the shelf. I don't see much difference in buying a propeller versus machining one. Anyone got an answer? Thank you!
Most likely this depends on the actual safety hazard involved. Some people say "if it's not illegal for minors, students should do it," while others might say the opposite. Regardless, the students should probably be designing the propeller.
I appreciate the timely response but do you think 6th - 8th graders have the ability to design and program (much less run a CNC machine tool) a propeller?
IMO if the students cannot design their own propeller, than they must find others ways to obtain it. CNC machine can be allowed to be the coachs responsibility, but not the design.

Re: Hovercraft B/C

Posted: October 21st, 2016, 10:08 pm
by Patrick Yepes
windu34 wrote:
Patrick Yepes wrote:
Unome wrote: Most likely this depends on the actual safety hazard involved. Some people say "if it's not illegal for minors, students should do it," while others might say the opposite. Regardless, the students should probably be designing the propeller.
I appreciate the timely response but do you think 6th - 8th graders have the ability to design and program (much less run a CNC machine tool) a propeller?
IMO if the students cannot design their own propeller, than they must find others ways to obtain it. CNC machine can be allowed to be the coachs responsibility, but not the design.



Thanks!

Re: Hovercraft B/C

Posted: October 22nd, 2016, 6:30 am
by RJohnson
Patrick Yepes wrote:do you think 6th - 8th graders have the ability to design and program (much less run a CNC machine tool) a propeller?
I would say absolutely yes. You would be very surprised at what they'll be able to do if you show them how the basics work. Remember, the whole point of SO is for the students to learn. Let them experiment and try it on their own. If they can't get it, give them guiding advice. Maybe let them do one part of the process and you take care of the actual machine. At any rate, I would encourage you to enable those students with a new skill, especially because you have access to such a machine.

I remember being that Junior High student, and it's the coolest thing in the world to learn something new and advanced for a SO project. It may take longer than you want and it may not be as perfect as you want, but they will have done it, and that's what matters.

Re: Hovercraft B/C

Posted: October 22nd, 2016, 11:02 am
by daycd
SPP SciO wrote:
daycd wrote:Is there a range for the target times specified? For example, what kind of top speed will be required to match the target time?
Rule 5.f - anywhere between 5.0 - 25.0 seconds, revealed after impound.
Thanks, I'm not sure how I missed that.

Re: Hovercraft B/C

Posted: October 22nd, 2016, 11:25 am
by Wen
Did someone asked about this already? The fan Chalker recommended (http://www.digikey.com/product-search/e ... 70-1126-ND) and a lot of such fans have 12VDC in spec. Would it be against the rule of 9V anywhere in the circuit? I suppose one can apply 9V for a reduced RPM but that becomes a variable.