Hovercraft B/C

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Re: Hovercraft B/C

Postby neutrino » Tue Apr 17, 2018 3:08 am

antoine_ego wrote:If you replace the motor, I'd recommend buying a bigger one so that if that one too fails at some point, it still can probably hold full weight.

It's a bit late for motor replacement unfortunately, but I got the biggest one I could possibly find (1019 Pa static pressure, pretty expensive too), and it worked well, until...rip

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Re: Hovercraft B/C

Postby antoine_ego » Tue Apr 17, 2018 3:14 am

neutrino wrote:
antoine_ego wrote:If you replace the motor, I'd recommend buying a bigger one so that if that one too fails at some point, it still can probably hold full weight.

It's a bit late for motor replacement unfortunately, but I got the biggest one I could possibly find (1019 Pa static pressure, pretty expensive too), and it worked well, until...rip

If worst comes to worst, just aim to ace the time score with a lower weight. You could try to put some floor pads on the inside of the skirt to ensure full inflation.
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Re: Hovercraft B/C

Postby jgrischow1 » Tue Apr 17, 2018 4:14 pm

Not sure if this has been mentioned, but pennies made before 1983 weigh about 25% more than post-1982 pennies. Do supervisors even check how much their rolls weigh?

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Re: Hovercraft B/C

Postby nicholasmaurer » Tue Apr 17, 2018 5:37 pm

jgrischow1 wrote:Not sure if this has been mentioned, but pennies made before 1983 weigh about 25% more than post-1982 pennies. Do supervisors even check how much their rolls weigh?


I don't believe I have ever observed a supervisor weigh their penny rolls to check for consistency. Because of the number of pennies involved, I would assume that supervisors request the rolls from a bank, in which case I would expect most (if not all) of the pennies to be post-1982.
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Re: Hovercraft B/C

Postby jgrischow1 » Tue Apr 17, 2018 6:29 pm

nicholasmaurer wrote:
jgrischow1 wrote:Not sure if this has been mentioned, but pennies made before 1983 weigh about 25% more than post-1982 pennies. Do supervisors even check how much their rolls weigh?


I don't believe I have ever observed a supervisor weigh their penny rolls to check for consistency. Because of the number of pennies involved, I would assume that supervisors request the rolls from a bank, in which case I would expect most (if not all) of the pennies to be post-1982.


Yeah, when I went to the bank, I got 14 rolls of mostly pre-1982 pennies and only 2 of mostly post-. Hopefully my experience was an outlier. 2.5 kg seems like a big difference from 2 kg.

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Re: Hovercraft B/C

Postby UTF-8 U+6211 U+662F » Tue Apr 17, 2018 7:17 pm

Rules say to assume 1 roll is ~125 g and 16 rolls is ~2 kg.

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Re: Hovercraft B/C

Postby jgrischow1 » Tue Apr 17, 2018 9:56 pm

UTF-8 U+6211 U+662F wrote:Rules say to assume 1 roll is ~125 g and 16 rolls is ~2 kg.


Indeed. I just wonder how many supervisors are aware the composition of pennies has changed and would think to weigh them.

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Re: Hovercraft B/C

Postby SlipStrike1244 » Fri Apr 20, 2018 1:57 pm

is it better to poke holes in the back of the skirt to make it go forward a bit or is that too little of a difference to matter.

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Re: Hovercraft B/C

Postby hippo9 » Fri Apr 20, 2018 2:11 pm

SlipStrike1244 wrote:is it better to poke holes in the back of the skirt to make it go forward a bit or is that too little of a difference to matter.

From what I've seen at competitions, there have been designs that rely on a hole in the back of the skirt as the sole source propulsion, but the issue with this is they are really unpredictable. Also, it probably wouldn't do much if you have a fan dedicated to propulsion already.
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Re: Hovercraft B/C

Postby antoine_ego » Fri Apr 20, 2018 2:13 pm

SlipStrike1244 wrote:is it better to poke holes in the back of the skirt to make it go forward a bit or is that too little of a difference to matter.


It does make a difference provided that your bottom fan has sufficiently high airflow. I only cut holes in the back if my craft is riding too high and I want it to be a bit lower. So long as you have a pretty powerful back fan, it might not be necessary, but it can be used to modulate the height.
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Re: Hovercraft B/C

Postby BasuSiddha23 » Thu Apr 26, 2018 7:40 pm

How many rolls of pennies can your hovercrafts hold?

I just want to see our performance compared to other teams.
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Re: Hovercraft B/C

Postby MattChina » Thu Apr 26, 2018 7:42 pm

BasuSiddha23 wrote:How many rolls of pennies can your hovercrafts hold?

I just want to see our performance compared to other teams.

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Re: Hovercraft B/C

Postby UTF-8 U+6211 U+662F » Thu Apr 26, 2018 8:24 pm

4 :|

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Re: Hovercraft B/C

Postby IvanGe » Fri Apr 27, 2018 12:35 pm

BasuSiddha23 wrote:How many rolls of pennies can your hovercrafts hold?

I just want to see our performance compared to other teams.


If you want to do well, get it to hold 16 rolls, most national teams already can easily hold 16 rolls. (Mine can also hold 16 rolls) However, some tournaments I've noticed that my hovercraft didn't float as well as others, with the same batteries and 16 rolls, therefore I assume maybe that the penny rolls were different as mentioned early.
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Re: Hovercraft B/C

Postby randomperson123 » Sun Apr 29, 2018 12:21 pm

Is the hovercraft written test self-scheduled at nationals?


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