Rubber

Locked
User avatar
mrsteven
Exalted Member
Exalted Member
Posts: 815
Joined: March 13th, 2011, 5:40 pm
Division: C
State: IL
Location: UIUC (Formerly BGHS)

Re: Rubber

Post by mrsteven » April 17th, 2011, 7:57 pm

chia wrote:We'll definitely be trying a winding stooge next year. I saw teams getting in 1100 winds (probably on 1/8) when we've barely been able to get 900.

Whoops, hadn't meant to double post.
well a winding stooge wont help that, that just makes 1 person winding easier/ easy way to do it off helicopter so that if it does break it wont mash up the helicopter.

amount of winds comes down to type of rubber, width of rubber, batch of rubber, type of lubricant, how much lubricant, etc
2011 Helicopters State Runner-up
2012 Helicopters State Champion
2013 Robot Arm State Champion

User avatar
chia
Member
Member
Posts: 558
Joined: January 13th, 2009, 5:09 pm
Division: Grad
State: IL
Location: Derse

Re: Rubber

Post by chia » April 17th, 2011, 8:04 pm

Well, when I wind off the copter, it feels safer to stretch it out farther. Also, I once wound a 2 gram loop from the same batch I've been working with all year around a doorknob or something, and it hadn't yet broken by 1100, when on the helicopter it breaks at 900 or less. Maybe I just suck at life or something :roll:
(avatar is by xamag)
Favorite events: Anatomy, Microbe Mission, Ornithology, Circuit Lab, Helicopter
NCHS '13
==>

User avatar
smartkid222
Exalted Member
Exalted Member
Posts: 774
Joined: June 22nd, 2008, 8:12 am
Division: C
State: NY
Location: Western Long Island

Re: Rubber

Post by smartkid222 » April 17th, 2011, 8:06 pm

illusionist wrote:Okay, so I tried a really low pitch (.8 vertical spacing and 3.5 tip to tip) and with 1,000 winds on 1/8, it rises about 14 feet, and falls back. So clearly lift is the issue. From what I know, if the pitch is higher, it should get more lift. But, in order for flight with 1/8, I needed to use a pretty low pitch. When I tried 1 inch with 2.75, it is too high for the rubber to provide the sufficient amount of lift. So is my reasoning right? I need to use a low enough pitch so that the rotors will actually spin with the power of 1/8, yet provide lift. Does it all come down to finding the right pitch, or is there anything else?
Btw, I'm using 1/8 FAI Tan Super Sport rubber. My helicopter is 4.05 grams.
Thanks in advance. I know I've asked similar questions a few times before.
So you're saying you are getting really low times? How many winds were left out of 1,000?
Image 2008 NY BLG Champ
2010 NY Helicopter Champ

User avatar
mrsteven
Exalted Member
Exalted Member
Posts: 815
Joined: March 13th, 2011, 5:40 pm
Division: C
State: IL
Location: UIUC (Formerly BGHS)

Re: Rubber

Post by mrsteven » April 17th, 2011, 8:06 pm

chia wrote:Well, when I wind off the copter, it feels safer to stretch it out farther. Also, I once wound a 2 gram loop from the same batch I've been working with all year around a doorknob or something, and it hadn't yet broken by 1100, when on the helicopter it breaks at 900 or less. Maybe I just suck at life or something :roll:
lol idk that but I think its because on the doorknob you stretched it out more?
2011 Helicopters State Runner-up
2012 Helicopters State Champion
2013 Robot Arm State Champion

User avatar
chia
Member
Member
Posts: 558
Joined: January 13th, 2009, 5:09 pm
Division: Grad
State: IL
Location: Derse

Re: Rubber

Post by chia » April 17th, 2011, 8:12 pm

Well, that's my point exactly! Or maybe I should just suck it up and stretch it out more on the helicopter. I'd just rather it snap on the stooge than straight on the helicopter.
(avatar is by xamag)
Favorite events: Anatomy, Microbe Mission, Ornithology, Circuit Lab, Helicopter
NCHS '13
==>

User avatar
mrsteven
Exalted Member
Exalted Member
Posts: 815
Joined: March 13th, 2011, 5:40 pm
Division: C
State: IL
Location: UIUC (Formerly BGHS)

Re: Rubber

Post by mrsteven » April 17th, 2011, 8:47 pm

chia wrote:Well, that's my point exactly! Or maybe I should just suck it up and stretch it out more on the helicopter. I'd just rather it snap on the stooge than straight on the helicopter.
yeah, we didnt use a stooge (forgot at home). so the 2 ppl i had flying it used the winder at one end. and holding it w/o being about to turn on the other end was a paperclip to hold the o-ring with a pair of scissors through it to stop turning
2011 Helicopters State Runner-up
2012 Helicopters State Champion
2013 Robot Arm State Champion

thewinner
Member
Member
Posts: 110
Joined: March 18th, 2011, 12:18 pm
Division: B
State: NJ
Location: TGMS FTW

Re: Rubber

Post by thewinner » April 18th, 2011, 4:20 am

We just had me turning the winder and my partner holding a pencil with the rubber around it.
I win.

User avatar
illusionist
Member
Member
Posts: 942
Joined: March 20th, 2010, 4:13 pm
Division: C
State: MI

Re: Rubber

Post by illusionist » April 18th, 2011, 7:54 am

smartkid222 wrote:
illusionist wrote:Okay, so I tried a really low pitch (.8 vertical spacing and 3.5 tip to tip) and with 1,000 winds on 1/8, it rises about 14 feet, and falls back. So clearly lift is the issue. From what I know, if the pitch is higher, it should get more lift. But, in order for flight with 1/8, I needed to use a pretty low pitch. When I tried 1 inch with 2.75, it is too high for the rubber to provide the sufficient amount of lift. So is my reasoning right? I need to use a low enough pitch so that the rotors will actually spin with the power of 1/8, yet provide lift. Does it all come down to finding the right pitch, or is there anything else?
Btw, I'm using 1/8 FAI Tan Super Sport rubber. My helicopter is 4.05 grams.
Thanks in advance. I know I've asked similar questions a few times before.
So you're saying you are getting really low times? How many winds were left out of 1,000?
Yeah, with the .8 pitch, I got all of 17 seconds :cry:
There are at least 700 winds remaining when it lands.
So if a lot of winds are left, it generally means that I should lower the pitch right? But I'm already at a ridiculously low pitch...
2012-2013 Building Event Captain
Rule 7d. "Event Supervisors are allowed to break any competitors' devices" -bearasauras

User avatar
mrsteven
Exalted Member
Exalted Member
Posts: 815
Joined: March 13th, 2011, 5:40 pm
Division: C
State: IL
Location: UIUC (Formerly BGHS)

Re: Rubber

Post by mrsteven » April 18th, 2011, 1:22 pm

jw because essentially this whole year I've been wondering this and someone recently brought this to my attention: by pitch angle, in which orientation do you mean? Idk if i've been measuring it the same way you have been. Like do you mean the angle of the spare; angle of 1 spare horizantal to the other lifted in the air?
2011 Helicopters State Runner-up
2012 Helicopters State Champion
2013 Robot Arm State Champion

User avatar
Draylon Fogg
Member
Member
Posts: 150
Joined: January 20th, 2010, 8:03 pm
Division: C
State: KS

Re: Rubber

Post by Draylon Fogg » April 19th, 2011, 12:48 pm

mrsteven wrote:jw because essentially this whole year I've been wondering this and someone recently brought this to my attention: by pitch angle, in which orientation do you mean? Idk if i've been measuring it the same way you have been. Like do you mean the angle of the spare; angle of 1 spare horizantal to the other lifted in the air?
oreintation means which way the propeller is spinning.
It's always tea time somewhere in the world...... Come to think of it... It's my tea time... :D
Events I participate:
chem lab
forensics
forestry
helicopter
sounds of music
remote sensing
water quality

Locked

Return to “Helicopters C”

Who is online

Users browsing this forum: No registered users and 1 guest