Boomilever B/C

[waffletree]

Is purchasing balsa wood worth it?

well yea unless you plan on using plywood or popsicle sticks or something
like for these type of building events balsa is by far the best choice to do the best you possibly can

[DarthBuilder]

In the rules it says that the loading block must be between 40-45 cm. Does this mean the actually loading block or the center of the block where the chain comes down?

[Carrot]

In the rules it says that the loading block must be between 40-45 cm. Does this mean the actually loading block or the center of the block where the chain comes down?

The center of the loading block.

[Cow481]

How would you figure out the length of the tension pieces. The window of length would seem very tight. If you make it to short, the boomilever would sit at a downward angle from the loading block angle and if it was to long, the boomilever would also sit at an upward angle from the loading block.

[retired1]

Answer to the question would be to use math. My preference would be to make a scale drawing and measure it.If the tension members are from the hook to the load eye bolt, then I think you have it reversed. But,if you have the angle of attachment to the main portion, then it will always be at a level orientation. The height above the do not exceed line will vary.

Not a problem if you accurately graph it. I like the large quad paper from office depot.

Actually, I put it in my "Model Smart 3 D" computer program and it does all of that for me as well as accurately predict the results for what ever densities I entered into it.

[TheSquaad]

Answer to the question would be to use math. My preference would be to make a scale drawing and measure it.If the tension members are from the hook to the load eye bolt, then I think you have it reversed. But,if you have the angle of attachment to the main portion, then it will always be at a level orientation. The height above the do not exceed line will vary.

Not a problem if you accurately graph it. I like the large quad paper from office depot.

Actually, I put it in my "Model Smart 3 D" computer program and it does all of that for me as well as accurately predict the results for what ever densities I entered into it.

I’d just build it on a testing wall. I made a version where the hook is about 14.8 cm above the bottom of a standing wall, so I can literally just build on top of a table and against the wall.

[OpticsNerd]

Any tips on how to make the J-Hook contact point strong?

[Unome]

Any tips on how to make the J-Hook contact point strong?

A dowel-shaped piece should suffice. Bass might be useful to avoid compressing the wood from the very high stress. I doubt other orientations provide enough benefit to be worth the cost of damaging wood fibers (e.g. bending).

[retired1]

I’d just build it on a testing wall. I made a version where the hook is about 14.8 cm above the bottom of a standing wall, so I can literally just build on top of a table and against the wall.

If you mean that the boom would touch the table--If I were the ES, I would disqualify your boom.

[dholdgreve]

How would you figure out the length of the tension pieces. The window of length would seem very tight. If you make it to short, the boomilever would sit at a downward angle from the loading block angle and if it was to long, the boomilever would also sit at an upward angle from the loading block.

This will depend on your unique design... How are you attaching at the top? How thick is your mounting block? Will the tension rod extend all the way through it? Where will your tension rod intersect the compression beam? Will it extend all the way past the compression beam?

I agree with Retired... Come up with your design, then draw a scale model, either pencil & paper, or CAD... Then just measure.

I can tell you this much: In 99% of the designs, your tension rods can come from 24" sticks and your compression beams can come from half of a 36" stick for ordering purposes.