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xiangyu wrote: ↑February 16th, 2020, 3:49 pm

sneepity wrote: ↑February 16th, 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.

Lorant wrote: ↑February 16th, 2020, 9:43 pm

sneepity wrote: ↑February 16th, 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.

Tall wrote: ↑February 17th, 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?

sneepity wrote: ↑February 17th, 2020, 6:20 pm

Tall wrote: ↑February 17th, 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.

Lorant wrote: ↑February 17th, 2020, 6:29 pm

sneepity wrote: ↑February 17th, 2020, 6:20 pm

Tall wrote: ↑February 17th, 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

sneepity wrote: ↑February 17th, 2020, 6:35 pm

Lorant wrote: ↑February 17th, 2020, 6:29 pm

sneepity wrote: ↑February 17th, 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.

Tall wrote: ↑February 18th, 2020, 6:08 am

sneepity wrote: ↑February 17th, 2020, 6:35 pm

Lorant wrote: ↑February 17th, 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."

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

bernard wrote: ↑February 18th, 2020, 8:27 am

Tall wrote: ↑February 18th, 2020, 6:08 am

sneepity wrote: ↑February 17th, 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

sneepity wrote: ↑February 18th, 2020, 7:44 pm

bernard wrote: ↑February 18th, 2020, 8:27 am

Tall wrote: ↑February 18th, 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

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!