Boomilever B/C

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sneepity
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Re: Boomilever B/C

Post by sneepity »

xiangyu wrote: Sun Feb 16, 2020 3:49 pm
sneepity wrote: Sun Feb 16, 2020 3:33 pm the compression pieces are uneven on my boomi , one touches the wall before the other. How would I fix this? thank you
Cut/sand down the longer one so they're even?
I tried to do that, but the problem is that I've already sanded what I could. My boomi is also very heavy, so Ill just test this one to get some insight and then just build a lighter one.
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Re: Boomilever B/C

Post by sneepity »

Lorant wrote: Sun Feb 16, 2020 9:43 pm
sneepity wrote: Sun Feb 16, 2020 3:33 pm the compression pieces are uneven on my boomi , one touches the wall before the other. How would I fix this? thank you
Draw up a template for the base, build it on the template with the pieces taped to it, then build the rest.
Thanks for the advice! Iĺl be sure to test it next time.
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Re: Boomilever B/C

Post by sneepity »

Tall wrote: Mon Feb 17, 2020 2:24 pm What is the shortest length boomi you guys are building?
uh mine is currently 45 so Iḿ using all of the space given.
Are shorter boomilevers better?
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Re: Boomilever B/C

Post by Lorant »

sneepity wrote: Mon Feb 17, 2020 6:20 pm
Tall wrote: Mon Feb 17, 2020 2:24 pm What is the shortest length boomi you guys are building?
uh mine is currently 45 so Iḿ using all of the space given.
Are shorter boomilevers better?
Yes, with a shorter radius you decrease torque excreted by the bucket, increase the angle between the compression and tension portions thus reducing the force of tension on the tension piece, not to mention the decreased length of the compression beam reduces its bending moment.
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Re: Boomilever B/C

Post by sneepity »

Lorant wrote: Mon Feb 17, 2020 6:29 pm
sneepity wrote: Mon Feb 17, 2020 6:20 pm
Tall wrote: Mon Feb 17, 2020 2:24 pm What is the shortest length boomi you guys are building?
uh mine is currently 45 so Iḿ using all of the space given.
Are shorter boomilevers better?
Yes, with a shorter radius you decrease torque excreted by the bucket, increase the angle between the compression and tension portions thus reducing the force of tension on the tension piece, not to mention the decreased length of the compression beam reduces its bending moment.
oh, thank you! what is the limit for how short the boomi should be? Thanks for the valuable info
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Re: Boomilever B/C

Post by Tall »

sneepity wrote: Mon Feb 17, 2020 6:35 pm
Lorant wrote: Mon Feb 17, 2020 6:29 pm
sneepity wrote: Mon Feb 17, 2020 6:20 pm
uh mine is currently 45 so Iḿ using all of the space given.
Are shorter boomilevers better?
Yes, with a shorter radius you decrease torque excreted by the bucket, increase the angle between the compression and tension portions thus reducing the force of tension on the tension piece, not to mention the decreased length of the compression beam reduces its bending moment.
oh, thank you! what is the limit for how short the boomi should be? Thanks for the valuable info
The shortest length from the center of the block to the wall must be 40 cm.
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Re: Boomilever B/C

Post by bernard »

Tall wrote: Tue Feb 18, 2020 6:08 am
sneepity wrote: Mon Feb 17, 2020 6:35 pm
Lorant wrote: Mon Feb 17, 2020 6:29 pm

Yes, with a shorter radius you decrease torque excreted by the bucket, increase the angle between the compression and tension portions thus reducing the force of tension on the tension piece, not to mention the decreased length of the compression beam reduces its bending moment.
oh, thank you! what is the limit for how short the boomi should be? Thanks for the valuable info
The shortest length from the center of the block to the wall must be 40 cm.
The rules mention "centerline of the chain."
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Re: Boomilever B/C

Post by BadDai »

My last couple boomilevers have all broken at the place where the block sits. My most recent boom broke at 12 kg and there was no buckling. It weighed about 10.9 g. I use a two piece compression, so it joins and the joint is glued with gorilla glue. Any ideas on how to make sure the boom doesn’t break where the block sits? Thanks :D
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Re: Boomilever B/C

Post by sneepity »

bernard wrote: Tue Feb 18, 2020 8:27 am
Tall wrote: Tue Feb 18, 2020 6:08 am
sneepity wrote: Mon Feb 17, 2020 6:35 pm
oh, thank you! what is the limit for how short the boomi should be? Thanks for the valuable info
The shortest length from the center of the block to the wall must be 40 cm.
The rules mention "centerline of the chain."
im not really sure what that means, lol :D
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Re: Boomilever B/C

Post by dholdgreve »

sneepity wrote: Tue Feb 18, 2020 7:44 pm
bernard wrote: Tue Feb 18, 2020 8:27 am
Tall wrote: Tue Feb 18, 2020 6:08 am
The shortest length from the center of the block to the wall must be 40 cm.
The rules mention "centerline of the chain."
im not really sure what that means, lol :D
I interpret "center of chain" as the same thing as "center of bolt" and measure accordingly. That said, the loading block is 5cm x 5cm with the bolt hole in the middle. The center of the bolt must be a minimum of 40cm from the wall, so to fully support the loading block, the boom must be a minimum of 42.5 cm long. If you choose to go shorter than that and cantilever part of the loading block beyond the end of the boom, that's on you!
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