General Discussion

Locked
User avatar
mrsteven
Exalted Member
Exalted Member
Posts: 815
Joined: March 13th, 2011, 5:40 pm
Division: C
State: IL
Has thanked: 0
Been thanked: 0

Re: General Discussion

Post by mrsteven »

questionguy wrote:Does the 70 cm include the base of the tower?
ya. 70cm is from bottom of tower to top
2011 Helicopters State Runner-up
2012 Helicopters State Champion
2013 Robot Arm State Champion
Vizard007
Member
Member
Posts: 44
Joined: August 28th, 2010, 11:47 pm
Division: C
State: CA
Has thanked: 0
Been thanked: 0

Re: General Discussion

Post by Vizard007 »

Well, we tried using a jig, but it still ended up crooked. :( I think it's because the actual wood itself is curved if I were to lay it on a flat surface. Is there a solution to this? Thanks so much for your help by the way!
It's so easy, even a Badger could do it.
jander14indoor
Member
Member
Posts: 1648
Joined: April 30th, 2007, 7:54 am
Has thanked: 0
Been thanked: 29 times

Re: General Discussion

Post by jander14indoor »

Two choices on curved wood I can think of.

Throw out the crooked pieces (better, don't buy them to start with). Good wood is critical in this event, don't saddle yourself with a handicap before you even start building.

Use the curves in equal and opposite directions so they offset each other and end up straight. This might even be useful in building in some preloads to force your structure to behave in certain ways as it is loaded, but that's a little tricky.

Jeff Anderson
Livonia, MI
Vizard007
Member
Member
Posts: 44
Joined: August 28th, 2010, 11:47 pm
Division: C
State: CA
Has thanked: 0
Been thanked: 0

Re: General Discussion

Post by Vizard007 »

jander14indoor wrote:Two choices on curved wood I can think of.

Throw out the crooked pieces (better, don't buy them to start with). Good wood is critical in this event, don't saddle yourself with a handicap before you even start building.

Use the curves in equal and opposite directions so they offset each other and end up straight. This might even be useful in building in some preloads to force your structure to behave in certain ways as it is loaded, but that's a little tricky.

Jeff Anderson
Livonia, MI
Oh, I see. Thank you so much! :) Also, I was wondering, what type of balsa grain are you guys using? Do you think it'd make a difference?
It's so easy, even a Badger could do it.
fanjiatian
Member
Member
Posts: 244
Joined: March 16th, 2010, 6:46 pm
Division: Grad
Has thanked: 0
Been thanked: 2 times

Re: General Discussion

Post by fanjiatian »

Do any of you have tips for steadying the bucket?

I find it extremely difficult to steady the bucket without having shaky hands.
User avatar
lucwilder42
Member
Member
Posts: 114
Joined: March 30th, 2010, 10:01 am
Division: Grad
State: MI
Has thanked: 0
Been thanked: 0

Re: General Discussion

Post by lucwilder42 »

fanjiatian wrote:Do any of you have tips for steadying the bucket?

I find it extremely difficult to steady the bucket without having shaky hands.
Have your partner do it. A shaky bucket can wreck a perfectly good tower very quickly
I'm just here to build bridges
fanjiatian
Member
Member
Posts: 244
Joined: March 16th, 2010, 6:46 pm
Division: Grad
Has thanked: 0
Been thanked: 2 times

Re: General Discussion

Post by fanjiatian »

Good idea.
Where is the best place for your hands to go?
Near the bottom or top of the bucket?
thsom
Member
Member
Posts: 241
Joined: December 27th, 2011, 10:26 am
Division: C
State: IL
Has thanked: 0
Been thanked: 0

Re: General Discussion

Post by thsom »

Hey guys, I just tested a tower and it held merely 2.57 kg :oops: . However, when I tested the base and chimney at home, both held over 15 kg. The tower broke at the connection. No wood actually snapped causing it to break, the chimney just literally quickly fell of of the base. Was it because of a small lean and improper/inadequate connection of the two because if I can fix this issue, I could have a nice tower.
User avatar
foreverphysics
Moderator
Moderator
Posts: 497
Joined: May 20th, 2011, 8:41 pm
Division: Grad
State: AL
Has thanked: 0
Been thanked: 69 times
Contact:

Re: General Discussion

Post by foreverphysics »

fanjiatian wrote:Good idea.
Where is the best place for your hands to go?
Near the bottom or top of the bucket?
Neither. Don't actually touch the bucket. Give it about a .5 cm margin to swing. Put your hands on either side of the bucket nearer the center, but again, don't touch the bucket. You can put more pressure on the bucket if you're not careful, and also, the more sand you dump in the bucket, the more stable it becomes. A large part of it also has to do with how you pour in the sand. I would suggest pouring the sand in a slow, large circle at first, gradually speeding up and centralizing. At the end, you should easily be able to dump full beakers of sand into the center of your bucket with no unbalancing effects.
Image
Physics is difficult for 99% of the world's population because they don't understand it. The other 1% know too much.

"Physics is a psychiatrist?"
User avatar
Frogger4907
Member
Member
Posts: 458
Joined: September 16th, 2010, 11:16 am
Division: Grad
State: KS
Has thanked: 0
Been thanked: 0

Re: General Discussion

Post by Frogger4907 »

thsom wrote:Hey guys, I just tested a tower and it held merely 2.57 kg :oops: . However, when I tested the base and chimney at home, both held over 15 kg. The tower broke at the connection. No wood actually snapped causing it to break, the chimney just literally quickly fell of of the base. Was it because of a small lean and improper/inadequate connection of the two because if I can fix this issue, I could have a nice tower.
Even the slightest lean will really affect the distribution of weight to one side of the tower causing it to snap much quicker. and unlevel testing surface could provide a similar affect.
Ornithology State Champion
Gravity Vehicle State Champion
Thermodynamics State Champion
Remote Sensing State Champion
>20 Div C State Medals
Locked

Return to “Towers B/C”

Who is online

Users browsing this forum: No registered users and 0 guests