Boomilever B/C

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Re: Boomilever B/C

Post by Oblivion »

What is the best way to connect the tension member and compression member through vertical bracing? My boomilver gets smaller in terms of width as I get closer to the distal end, so should I connect the bracing inside of the compression member or outside?
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Re: Boomilever B/C

Post by sneepity »

jinhusong wrote: March 3rd, 2020, 11:33 am
scioly2345 wrote: March 3rd, 2020, 9:36 am
jinhusong wrote: March 3rd, 2020, 9:33 am

We use basswood base and pre-dented with 40kg pulling. The distal still went lower more than one cm before the boomi broke at 9kg.
Mostly is because the stretch of the tension.
Wdym by “40kg pulling”?
We put a 1/4X1/2 stick on the hook, then pull the hook with luggage scale to 40kg. It will leave a dent on the stick, then we cut the stick around the dent to make the base.
wait im sorry how does that work?
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Re: Boomilever B/C

Post by MoMoney$$$;)0) »

Come on people we need to add to the best of 2020

Best of 2020

If you guys don't know how to add to the WIki, share me the photo privately, and I can add it on. :D
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Re: Boomilever B/C

Post by MadCow2357 »

MoMoney$$$;)0) wrote: March 23rd, 2020, 10:41 am Come on people we need to add to the best of 2020

Best of 2020

If you guys don't know how to add to the WIki, share me the photo privately, and I can add it on. :D
Just saying, I wouldn't expect too many boomi submissions lol
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Re: Boomilever B/C

Post by MoMoney$$$;)0) »

MadCow2357 wrote: March 25th, 2020, 4:28 pm
MoMoney$$$;)0) wrote: March 23rd, 2020, 10:41 am Come on people we need to add to the best of 2020

Best of 2020

If you guys don't know how to add to the WIki, share me the photo privately, and I can add it on. :D
Just saying, I wouldn't expect too many boomi submissions lol
Not much of anything at all yet, but we'll see.
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Re: Boomilever B/C

Post by sneepity »

scioly2345 wrote: February 28th, 2020, 6:42 am
JonB wrote: February 27th, 2020, 10:33 am
scioly2345 wrote: February 27th, 2020, 5:51 am Hi Boomilever people,

So I need some advice on attaching verticals. I don’t know whether to use bass or balsa, or how to get them on properly because of the annoying angles of the compression and tension pieces. My breaks this season have mostly been compression explosions because they bend upwards. Any tips on how to do this? I just want to do one vertical on each side of the boomi so I can shrink the size of my compression to save mass. So far I’ve just made the main supports of my compression so tall and thick to the point where verticals aren’t needed, but with that comes the fact that the compression is so. heavy. Which is not cool efficiency wise.
My next steps to make my boomi lighter is 1. Learn how to properly do verticals so I can shrink my compression and 2. Change my bass size from 1/8x1/16 to either 1/8x1/32 or 3/16x1/32 for tension. I have experimented taking off lamination at either the hook area (I use a dowel) or the distal end, but that very experimenting told me that that excessive lamination, although mass consuming, is not optional, so I’m not going to mess around with lamination. I’d rather have a compression break than a lamination/dowel break for sure.

My peak efficiency this year was a 1.7k but the highest I’ve gotten at competition is 1.5k, because I’ve been too scared to go to light because I don’t want to lose the bonus. UPenn efficiencies were scary good. So I need something to save lots of mass for NYS. My guess is around 1.3k for top ten, but I have NO idea of the competitiveness of the top 5.

A few things to consider here. Learning how to properly do verticals that are light is a huge challenge but is an absolute must if you want a light design that can hold the full load. For your bass tension pieces- do they hold full load? If so, make them lighter. Find the lightest you can use that can still hold full weight. I would move away from a dowel at the connection and experiment with some other designs. We use bass in tension and our verticals are all balsa.

I understand going "conservative" at competition but (especially this year) no risk, less reward. Our team"flirts" with disaster in boomi. We know it will break around 15kg and usually it holds, and sometimes it doesn't (looking at you, MIT). UPenn was relatively competitive with just a handful of scores at, or above, 2k but I am sure there will be more above 2k at the NY state championship.

Weigh the pieces of your boomi. Which are the heaviest? Do they need to be that heavy? Only way to know is to keep building, change one thing, and then record results. If those pieces hold up easily, make them lighter.
My tension is QUITE heavy, like everything with lamination can come out to 4 grams.
Compression I don’t wanna really mess with.
But with the verticals, how do you deal with attaching verticals when the angles the tension and compression are at are so annoyingly hard to deal with?
how much do you taper your tension sticks in at the j hook base? also what is the width of your boomilever at the distal end? I want to try and help, Idk how much I can though :D
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Re: Boomilever B/C

Post by scioly2345 »

sneepity wrote: March 31st, 2020, 11:34 am
scioly2345 wrote: February 28th, 2020, 6:42 am
JonB wrote: February 27th, 2020, 10:33 am


A few things to consider here. Learning how to properly do verticals that are light is a huge challenge but is an absolute must if you want a light design that can hold the full load. For your bass tension pieces- do they hold full load? If so, make them lighter. Find the lightest you can use that can still hold full weight. I would move away from a dowel at the connection and experiment with some other designs. We use bass in tension and our verticals are all balsa.

I understand going "conservative" at competition but (especially this year) no risk, less reward. Our team"flirts" with disaster in boomi. We know it will break around 15kg and usually it holds, and sometimes it doesn't (looking at you, MIT). UPenn was relatively competitive with just a handful of scores at, or above, 2k but I am sure there will be more above 2k at the NY state championship.

Weigh the pieces of your boomi. Which are the heaviest? Do they need to be that heavy? Only way to know is to keep building, change one thing, and then record results. If those pieces hold up easily, make them lighter.
My tension is QUITE heavy, like everything with lamination can come out to 4 grams.
Compression I don’t wanna really mess with.
But with the verticals, how do you deal with attaching verticals when the angles the tension and compression are at are so annoyingly hard to deal with?
how much do you taper your tension sticks in at the j hook base? also what is the width of your boomilever at the distal end? I want to try and help, Idk how much I can though :D
well the dowel I use at the base (yes I use a dowel, different from most people's rectangular bases) is only about 1.2 cm, and my distal end goes down to 4cm.
Wait now that I think about it why don't I try to shrink my distal end
The angle of the tension when it goes from the 1.2cm base to the 4cm distal end is mostly what caused the verts to be so hard
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Re: Boomilever B/C

Post by sneepity »

scioly2345 wrote: April 3rd, 2020, 5:46 pm
sneepity wrote: March 31st, 2020, 11:34 am
scioly2345 wrote: February 28th, 2020, 6:42 am
My tension is QUITE heavy, like everything with lamination can come out to 4 grams.
Compression I don’t wanna really mess with.
But with the verticals, how do you deal with attaching verticals when the angles the tension and compression are at are so annoyingly hard to deal with?
how much do you taper your tension sticks in at the j hook base? also what is the width of your boomilever at the distal end? I want to try and help, Idk how much I can though :D
well the dowel I use at the base (yes I use a dowel, different from most people's rectangular bases) is only about 1.2 cm, and my distal end goes down to 4cm.
Wait now that I think about it why don't I try to shrink my distal end
The angle of the tension when it goes from the 1.2cm base to the 4cm distal end is mostly what caused the verts to be so hard
or you could make your dowel a little wider, lets say, 2cm. but that may be bad bc the wider the dowel the weaker it is, so maybe *try* a rectangular base. Also guess you could shrink your distal end too! just make sure it is 8cm+ at the testing wall. :) glad I could help.
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