Search found 11 matches

by 55555
February 21st, 2017, 5:23 pm
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

MrGood wrote:How complex is the Hovercraft test in regards to calculus types of questions
Pretty sure there isn't any calc based physics.
MrGood wrote:How do you calculate CFM of a motor

Is the CFM based off of RPM?
If it's a computer cooling fan, the manufacturer will usually tell you.
by 55555
February 19th, 2017, 11:28 am
Forum: Robot Arm C
Topic: Pictures and scores
Replies: 27
Views: 5460

Re: Pictures and scores

5th at MIT with 259 points (regional scoring) https://drive.google.com/file/d/0Bzy9zNATXGUqSGEwUV81RGdjSzg/view?usp=drivesdk https://drive.google.com/file/d/0Bzy9zNATXGUqeFp6aHo5emlKTmc/view?usp=drivesdk Are you using standard sized servos on the elbow and wrist? What stall torque ratings are the s...
by 55555
February 19th, 2017, 9:15 am
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

Can someone explain to me why some teams are using a sideways facing fan in place of a downward facing lift fan? I saw this at a recent tournament and the only purpose I can think of is to act as a sort of flywheel maybe?
by 55555
February 17th, 2017, 5:38 am
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

For those of you using a potentiometer to vary voltage, how have you guys dealt with the potentiometer heating up. Our potentiometer(5ohm 5W) heats up so much that its resistance goes way up and doesn't give the fan enough voltage midrun and our hovercraft just stops.
by 55555
January 4th, 2017, 9:04 pm
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

If a fan has more than two wires coming out of it, it would still be allowed as it is "imbedded into a commerically available electronic or computer cooling fan," correct?
Yes, I believe so.
by 55555
January 2nd, 2017, 2:05 pm
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

So after I built my circuit for the thrust fan (back facing fan), my 0.15W potentiometer burned out. After doing some calculations: P=IV --> P=(1A)(7.4V), I get that I need a 7.4W potentiometer. Is this right? The potentiometers I've seen rated at ~8W are upwards of $100. Is a potentiometer not a vi...
by 55555
December 8th, 2016, 4:33 pm
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

So are you guys going to use computer fans for the thrust fan too b/c I'm having trouble finding brushed motors that can fit propellers/ come with propellers.
by 55555
November 26th, 2016, 3:32 pm
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

a small digital volt meter (also affordable)
Wouldn't a volt meter attached to the wires be illegal b/c it uses an integrated circuit?
by 55555
November 12th, 2016, 4:54 pm
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

Seems I was mislead by another website that said they used some kind of gel electrolyte that was considered lead acid :/ Yea, reviews say it starts out at about 8.4V and goes down to 7V. Are Li-ion and Li-polymer the same thing? I was thinking about using Lipos but I don't really feel like spending ...
by 55555
November 12th, 2016, 3:38 pm
Forum: 2017 Lab Events
Topic: Hovercraft B/C
Replies: 906
Views: 123787

Re: Hovercraft B/C

So are lead acid batteries allowed? I didn't see anything in the hovercraft rules about it, although they're not allowed in other build events. Apparently these batteries are lead acid and I want to use them. https://www.amazon.com/EBL%C2%AE-Battery-Charger-Rechargeable-Batteries/dp/B00EY6BZWS/tag=m...

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