Boomilever B/C

michiganmarc
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Re: Boomilever B/C

Post by michiganmarc » March 5th, 2020, 7:44 am

[/quote]
Despite the debate of 1/16 square v. 1/32 square v. 1/32x3/16 v. 1/16x1/8 (what I use), wouldn’t a rectangle size (despite the obvious heavier mass) just be more efficient because the flat side gives a larger surface area to connect tension to compression on the distal end? Last season the most frustrating breaks I’ve had are at the base or hook area, but this season the most frustrating breaks are at the distal end, the tension popping off because I didn’t laminate it enough. Even for states I’m scared to go down to a 1/32 by 1/8 size, but I might try out 3/16 by 1/32, which I suspect the masses for those will be the same as 1/16 by 1/8, if not SLIGHTLY different, either heavier or lighter. Not sure. I might just stick to my normal size since states is in a week and I don’t have much time to experiment.
[/quote]

We definitely like to use rectangular shaped tension members for that reason. There are many designs for both the base and distal ends. These two critical joints are probably the most challenging aspects of the boomi, especially this year when you really need to hold 15kg for maximum scoring. The higher density the wood, the less likely you are to have one of these joints "tear", not a glue failure, but an actual wood shear event. Of course, higher density means more weight. You also have to have both pieces being glued together have "compatible" densities, meaning it won't do you any good if you have a really strong tension member attached to a very weak/light beam as it will just shear the lighter wood.

If you are approaching a critical competition like States, I'd recommend sticking with what you know and be more conservative. It's better (and much easier) to have an 11g boomi hold 15kg than an 8g one hold 14kg.

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Re: Boomilever B/C

Post by dholdgreve » March 5th, 2020, 8:43 am

There are ways to distribute the load transfer to less dense members so they don't "blow out" the lighter wood.
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Re: Boomilever B/C

Post by dholdgreve » March 5th, 2020, 8:51 am

[
[/quote]
Despite the debate of 1/16 square v. 1/32 square v. 1/32x3/16 v. 1/16x1/8 (what I use), wouldn’t a rectangle size (despite the obvious heavier mass) just be more efficient because the flat side gives a larger surface area to connect tension to compression on the distal end? Last season the most frustrating breaks I’ve had are at the base or hook area, but this season the most frustrating breaks are at the distal end, the tension popping off because I didn’t laminate it enough. Even for states I’m scared to go down to a 1/32 by 1/8 size, but I might try out 3/16 by 1/32, which I suspect the masses for those will be the same as 1/16 by 1/8, if not SLIGHTLY different, either heavier or lighter. Not sure. I might just stick to my normal size since states is in a week and I don’t have much time to experiment.
[/quote]

I don't care for the 1/32 material for tension rods... I know teams do it all the time, but any grain imperfections will allow the grain to pull apart much easier with that thin of material. Think of ways that you might be able to utilize 1/16" x 1/16" material through the majority of the rods, then thicken them up at the ends to provide more surface area for the connections... There are several ways that might work... slots, mortises, gussets... all can be used effectively in this event.
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"For the betterment of Science"

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Re: Boomilever B/C

Post by scioly2345 » March 5th, 2020, 11:49 am

dholdgreve wrote:
March 5th, 2020, 8:51 am
[
Despite the debate of 1/16 square v. 1/32 square v. 1/32x3/16 v. 1/16x1/8 (what I use), wouldn’t a rectangle size (despite the obvious heavier mass) just be more efficient because the flat side gives a larger surface area to connect tension to compression on the distal end? Last season the most frustrating breaks I’ve had are at the base or hook area, but this season the most frustrating breaks are at the distal end, the tension popping off because I didn’t laminate it enough. Even for states I’m scared to go down to a 1/32 by 1/8 size, but I might try out 3/16 by 1/32, which I suspect the masses for those will be the same as 1/16 by 1/8, if not SLIGHTLY different, either heavier or lighter. Not sure. I might just stick to my normal size since states is in a week and I don’t have much time to experiment.
[/quote]

I don't care for the 1/32 material for tension rods... I know teams do it all the time, but any grain imperfections will allow the grain to pull apart much easier with that thin of material. Think of ways that you might be able to utilize 1/16" x 1/16" material through the majority of the rods, then thicken them up at the ends to provide more surface area for the connections... There are several ways that might work... slots, mortises, gussets... all can be used effectively in this event.
[/quote]
Grain imperfections (which are not good at ALL) have a little bit of wiggle room in my opinion. I bought “bad” bass for like half the season I used bass that was really poorly cut with a lot of imperfections along this sticks, and I was able to get away with none of them breaking. Of course it’s different in 1/8x1/16 than 1/32 square or even 1/16 or 3/32 square, but idk I think bass is what makes boomi relatively easy AND relativity hard.
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Re: Boomilever B/C

Post by SergioEdwards » March 5th, 2020, 12:18 pm

What are some average weights for booms? I'm just curious what my goal should be

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Re: Boomilever B/C

Post by dholdgreve » March 5th, 2020, 12:39 pm

SergioEdwards wrote:
March 5th, 2020, 12:18 pm
What are some average weights for booms? I'm just curious what my goal should be
I think it depends a lot on where you are located as to how competitive it gets
Here in Ohio:
A good boom weighs less than 10 grams,
A great boom weighs less that 9 grams
An AMAZING boom weighs less than 8 grams

It goes without saying, that all of these must carry full load
Dan Holdgreve
Northmont Science Olympiad

Dedicated to the Memory of Len Joeris
"For the betterment of Science"

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Re: Boomilever B/C

Post by will0416 » March 5th, 2020, 1:22 pm

dholdgreve wrote:
March 5th, 2020, 12:39 pm
SergioEdwards wrote:
March 5th, 2020, 12:18 pm
What are some average weights for booms? I'm just curious what my goal should be
I think it depends a lot on where you are located as to how competitive it gets
Here in Ohio:
A good boom weighs less than 10 grams,
A great boom weighs less that 9 grams
An AMAZING boom weighs less than 8 grams

It goes without saying, that all of these must carry full load
I wonder how many teams will be under 8 with reliable boomis by states. Maybe 2 or 3?
Mason ‘22
2019 Nats:
Code - 4
Mission - 4

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SergioEdwards
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Re: Boomilever B/C

Post by SergioEdwards » March 5th, 2020, 2:26 pm

will0416 wrote:
March 5th, 2020, 1:22 pm
dholdgreve wrote:
March 5th, 2020, 12:39 pm
SergioEdwards wrote:
March 5th, 2020, 12:18 pm
What are some average weights for booms? I'm just curious what my goal should be
I think it depends a lot on where you are located as to how competitive it gets
Here in Ohio:
A good boom weighs less than 10 grams,
A great boom weighs less that 9 grams
An AMAZING boom weighs less than 8 grams

It goes without saying, that all of these must carry full load
I wonder how many teams will be under 8 with reliable boomis by states. Maybe 2 or 3?
Our regional was won with a 15 gram-ish boom... Does anyone know what won theirs? I am fairly confident that it'll be impossible to have an 8-gram boom and hold it all.

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Re: Boomilever B/C

Post by will0416 » March 5th, 2020, 2:29 pm

SergioEdwards wrote:
March 5th, 2020, 2:26 pm
will0416 wrote:
March 5th, 2020, 1:22 pm
dholdgreve wrote:
March 5th, 2020, 12:39 pm

I think it depends a lot on where you are located as to how competitive it gets
Here in Ohio:
A good boom weighs less than 10 grams,
A great boom weighs less that 9 grams
An AMAZING boom weighs less than 8 grams

It goes without saying, that all of these must carry full load
I wonder how many teams will be under 8 with reliable boomis by states. Maybe 2 or 3?
Our regional was won with a 15 gram-ish boom... Does anyone know what won theirs? I am fairly confident that it'll be impossible to have an 8-gram boom and hold it all.
8 grams has been done this season before, i just thought it would be interesting to see how the top Ohio teams would fare
Mason ‘22
2019 Nats:
Code - 4
Mission - 4

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xiangyu
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Re: Boomilever B/C

Post by xiangyu » March 5th, 2020, 2:53 pm

SergioEdwards wrote:
March 5th, 2020, 2:26 pm
Our regional was won with a 15 gram-ish boom... Does anyone know what won theirs? I am fairly confident that it'll be impossible to have an 8-gram boom and hold it all.
Nothing is impossible. I bet with enough tweaking, we may even see 6.5ish g booms that hold all.
2020 Events: WS, GV, Boomi, PPP, WIDI, Machines, Detector, Digital

BEARSO/SOLVI/Solon/UMich/Allendale
Heli: 1/NA/NA
WICI: 33/NA/26
Machines: 81/42/53
Detector: -/49/39
WS: NA/NA/2
Digital: 38/NA/1
Boomi: NA/NA/4

Medal & Ribbon Count: 9
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