Boomilever B/C

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MadCow2357
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Re: Boomilever B/C

Post by MadCow2357 »

dankdecidueye wrote: January 2nd, 2020, 2:11 pm is going for max load worth it this year or no
Of course
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Re: Boomilever B/C

Post by donutsandcupcakes »

dankdecidueye wrote: January 2nd, 2020, 2:11 pm is going for max load worth it this year or no
I think if someone goes for the bonus then their score will DEFINETlY go up, so I mean its worth trying. I mean it depends like for example I know that I won't be able to hold the max weight no matter how hard I try, so I prob won't try, but someone who feels like they can hold max weight then I mean they should try. I guess it depends on how confident u r.. Does that help? I feel it makes it more confusing... :shock:

EDIT: I agree with @madcow
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Re: Boomilever B/C

Post by knightmoves »

dankdecidueye wrote: January 2nd, 2020, 2:11 pm is going for max load worth it this year or no
5kg is a huge bonus. Suppose your current boomilever is a 10g device that holds 10kg, so scores 1000. If you can strengthen it enough to hold 15 kg with less than 10g of additional mass, you win.

If you're currently holding 10kg with a 5g device, you're scoring 2000. Again, you can probably hold 50% more weight without doubling the mass of your boomilever.

If you're currently holding 5kg with a 5g device, and scoring 1000, you're again equal in score with a 20g device that holds full weight, so you should probably think about beefing your design up.

If you're holding 5kg with a 10g device, you're scoring 500. That's the same as holding full whack with a 40g behemoth.
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Re: Boomilever B/C

Post by LoneMonkey »

Hello! I was just wondering how much the "grain" of the wood actually affects the strength of the wood? I heard that C grain is the best. Can anyone confirm?
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Re: Boomilever B/C

Post by jinhusong »

LoneMonkey wrote: January 5th, 2020, 5:01 pm Hello! I was just wondering how much the "grain" of the wood actually affects the strength of the wood? I heard that C grain is the best. Can anyone confirm?
We use C grain for 1/8X1/4 compression beam. If the section is square, the grain will not mater. We do not have data to compare different grains. Just common sense that C grain should be stronger to against up-down bend.

As I wrote last year, the lines you can see in balsa wood is different from normal wood. They are Rays, not grains, which are 90 degree off from grain.
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Re: Boomilever B/C

Post by scioly2345 »

knightmoves wrote: December 30th, 2019, 11:13 am
donutsandcupcakes wrote: December 30th, 2019, 7:51 am Weird question but if i have 4 sticks of wood, should i use the heavier 2 for compression or for tension? bc im going to have bracings in my compression but i dont if i should use the heavier sticks for tension membranes.. pls help
How does the maxiumum force you can exert on a stick in compression change with its length? How does the maximum force you can exert in tension change with the length of the stick? How do those things change with the cross section of the stick? Answer those questions, and you'll understand your answer.
donutsandcupcakes wrote: December 30th, 2019, 7:51 am Also another question, for my 8 cm im thinking of making it 8.5 just to be safe, but am i making a mistake?
No. You're right that you want to make it a little bigger than the rules to allow a safety margin (your ruler might not be the same as the ES's ruler. You might not build it right. It might not hang quite straight when you mount it on the test wall. etc. etc. Whether the right answer is 8.5cm, 8.2cm, or 9.0cm depends on how confident you are...

I think you'll see that if you calculate the extra mass you introduce by changing the width from 8.0 to 8.5cm, you'll find that it makes little difference.
To add onto the 8cm thing, yes bigger than legal is better however I’d go very very safe in that area. I go for 10 cm just to be safe, and also i definitely take advantage of the vertical lines when adjusting the boom when in competition for centering (because we’re not allowed to bring levels :((((()
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Re: Boomilever B/C

Post by glin1011 »

Any tips for stabilizing?

My partner from last year graduated and now I have a new one - no lie, I love my partner a lot but I know she's having trouble stabilizing/steadying our bucket, and because of this we are usually 150-200 off our goal compared to our previous years.
Because I usually take care of the building portion, I don't really know how to help her with the stabilizing except say "Just keep holding or do strength training" but I'm concerned for our Regionals. Any tips or tricks to help? I know it sounds kinda dumb.
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Re: Boomilever B/C

Post by knightmoves »

glin1011 wrote: January 9th, 2020, 1:38 pm My partner from last year graduated and now I have a new one - no lie, I love my partner a lot but I know she's having trouble stabilizing/steadying our bucket, and because of this we are usually 150-200 off our goal compared to our previous years.
Because I usually take care of the building portion, I don't really know how to help her with the stabilizing except say "Just keep holding or do strength training" but I'm concerned for our Regionals. Any tips or tricks to help? I know it sounds kinda dumb.
Relax. If she's finding it hard, I bet she's pressing too hard on the bucket. You don't need much pressure, and you don't need to keep the bucket perfectly still at all times - just keep it under control. A light touch at the side of the bucket near the bottom is adequate.

If she just can't hold sticks without shaking, have her try squatting by the bucket, and bracing the ends of the sticks against her legs - that way, she has two points of contact with the stick, and isn't trying to hold it straight with just her wrists.
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Re: Boomilever B/C

Post by LoneMonkey »

Hello! I was wondering what people are doing for their hook connections? I tried putting a 1/4*1/8 piece between my tension members and laminating on top, bottom, sides, and back, but it broke super easily : (
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Re: Boomilever B/C

Post by donutsandcupcakes »

LoneMonkey wrote: January 10th, 2020, 12:34 pm Hello! I was wondering what people are doing for their hook connections? I tried putting a 1/4*1/8 piece between my tension members and laminating on top, bottom, sides, and back, but it broke super easily : (
What glue are you using? I would suggest using gorilla glue. Gorilla glue usually makes it stronger but it IS heavier..
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