Ongoing Contest(Scores)

Balsa Man
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Re: Ongoing Contest(Scores)

Postby Balsa Man » December 29th, 2012, 9:03 am

You know, thinking more about it, there is one rule difference that could work to improve scores vs '08- the removal of the 1/4" limit on cross section dimension. Where it plays in is when you go hollow construction for compression members (box beam or tube)- using 1 or 2 "single" compression members (as opposed to a truss/'tower on it's side" approach). As discussed elsewhere, significant structural efficiency advantages over solid cross-section members is significant....
Len Joeris
Fort Collins, CO

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Re: Ongoing Contest(Scores)

Postby UQOnyx » December 29th, 2012, 3:05 pm

This is kind of sad. Our Science Olympiad Team is only 3 years old. I am reading these, and I am getting really depressed. Me and my partner don't have any coaches or anyone to help us out and no prior experience. The highest that we got for a light building event for towers was 2nd place at regionals :oops: We do have a shot though because we got ~750 on our first trial and that was only because our mass was 20g since the compression members were bass since we didn't have anything left. Oh well :| XD
Noor-ul-Iman School

2012 Events:
Forestry
Storm The Castle


2013 Events:
Boomilever
Shock Value
Forestry


I know the voices aren't real, but they have some great ideas..

theging
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Re: Ongoing Contest(Scores)

Postby theging » December 29th, 2012, 3:29 pm

This is kind of sad. Our Science Olympiad Team is only 3 years old. I am reading these, and I am getting really depressed. Me and my partner don't have any coaches or anyone to help us out and no prior experience. The highest that we got for a light building event for towers was 2nd place at regionals :oops: We do have a shot though because we got ~750 on our first trial and that was only because our mass was 20g since the compression members were bass since we didn't have anything left. Oh well :| XD
Remember that you are not alone. In most regions, your team will do great with scores like that. There are many, many inexperienced teams throughout the country that would kill for a 750 score (kudos by the way). That being said, have you simply asked your parents for help? You may be surprised at how involved they may get in S.O.! In my school system, when I was in B division, many of the coaches were parents who wanted to help. And guess what? We did decently. Now, C is a whole 'nother world haha. But seriously, ask parents, friends of parents, teachers, anybody for some help and you'll be surprised at how much you'll learn from them. Also, look online for help. There are tons of websites that will give you tidbits of info that end up being vital to success (check out the wiki for boomilever; you can get a link by pressing the "wiki" button at the top of this page and selecting boomilever).

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Re: Ongoing Contest(Scores)

Postby Balsa Man » December 29th, 2012, 3:49 pm

RIGHT ON!
I agree on all counts
B-div, never did booms, 750-EXCELLENT. You're a lot better off than someone with a 10gr boom that's breaking at...6kg. Try lightening things one piece at a time.

I got into coaching from helping my sons. Too much fun to stop when they graduated.

There is indeed a lot of info on the web. There is a lot of very good, specific info right here- worth careful studying- from very basic, up through important "how to" detail, to detailed info on the physics.

Keep up the good work- feel free to ask questions. Enjoy!
Len Joeris
Fort Collins, CO

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Re: Ongoing Contest(Scores)

Postby iwonder » January 1st, 2013, 11:38 am

Woooo! Tested a new boom today, it weighed 15.88g and held 17.7kg(whoops...). It hasn't broke yet, so the next step is lighter tension members and box-beam compression members. What's the current thinking on loading the same structure twice? I've heard of people pre-loading structures to a certain percentage of the max load to let the structure settle, but I'm also concerned that some of the wood fibers may have been broken and the structure weakened enough that it'll fail early if I reload it at the next contest...
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Re: Ongoing Contest(Scores)

Postby UQOnyx » January 1st, 2013, 12:12 pm

Woooo! Tested a new boom today, it weighed 15.88g and held 17.7kg(whoops...). It hasn't broke yet, so the next step is lighter tension members and box-beam compression members. What's the current thinking on loading the same structure twice? I've heard of people pre-loading structures to a certain percentage of the max load to let the structure settle, but I'm also concerned that some of the wood fibers may have been broken and the structure weakened enough that it'll fail early if I reload it at the next contest...

Was this a ladder boom? If so, what were the specs of the compression. I am using 3/16 x 1/4 (couldn't find anything else ;) ). I'm testing today :D Btw awesome score!
Noor-ul-Iman School

2012 Events:
Forestry
Storm The Castle


2013 Events:
Boomilever
Shock Value
Forestry


I know the voices aren't real, but they have some great ideas..

iwonder
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Re: Ongoing Contest(Scores)

Postby iwonder » January 1st, 2013, 2:48 pm

Thanks! And yes, it was a ladder boom, the compression members were 1/8"x3/8".

theging
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Re: Ongoing Contest(Scores)

Postby theging » January 1st, 2013, 3:20 pm

What's everyone's top all time boom score? If you don't want that info out it's okay haha. Mine's 1338.

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Re: Ongoing Contest(Scores)

Postby Balsa Man » January 1st, 2013, 3:55 pm

Woooo! Tested a new boom today, it weighed 15.88g and held 17.7kg(whoops...). It hasn't broke yet, so the next step is lighter tension members and box-beam compression members. What's the current thinking on loading the same structure twice? I've heard of people pre-loading structures to a certain percentage of the max load to let the structure settle, but I'm also concerned that some of the wood fibers may have been broken and the structure weakened enough that it'll fail early if I reload it at the next contest...
Very nice!
Re-using after a full load.....all depends on how.....close to the edge it got. And the concern is as you suspect, wood fibers breaking (instead of staying in elastic deformation . Also, possible glue joints could have started to fail, so would be weaker 2nd time around. Did it....talk when at/close to max? That would make damage more likely.

Since you're gonna do a lighter one, try re-testing this one- see what it does.
Len Joeris
Fort Collins, CO

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Re: Ongoing Contest(Scores)

Postby iwonder » January 1st, 2013, 4:46 pm

I'm not actually sure how close to the edge it got, I was listening for creaking and checking every once in a while for buckling, but from a visual/audible standpoint it was the same as an unloaded boom. I did notice a significant amount of stretch in the tension members(the bucket dropped upwards of an inch and a half over the test), actually, halfway through I had to stop and reset the bucket a little higher on the chain.

I'm going to build a lighter one, but I'm not sure when I'll be able to get to it, I have to order some more thin balsa sheet to use... What I'll probably do is retest when school starts back up next week and if it hold 15kg I figure it should be good for contest(that would mean it made it to 17kg without significant damage)


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