Boomilever B/C

[123445]

I've noticed some people talking about a trapezoidal design for the compression members. How would you put bracing on the sides of the trapezoid?

[dankdecidueye]

wait what do you mean by trapezoid?

[dankdecidueye]

sorry for double posting, but is tower chimney still a good design structure or is it not great anymore due to rules?

[MadCow2357]

sorry for double posting, but is tower chimney still a good design structure or is it not great anymore due to rules?

Modified ofc - otherwise it would not be legal. But the concept is good imo.

I think trapezoid means the overall footprint from the front of the boomilever is trapezoidal - hard to explain in words but I don't have the time to make a graphic lol

[scioly2345]

wait what do you mean by trapezoid?

To have a legal boom, I would say most people this year take their 2019 design and widen compression at the wall (satisfying the 8 cm rule), and they narrow it down towards the distal end (satisfying the 5 cm block). This narrowing makes the compression look like a trapezoid like this —> \ / <— the top being against the wall and the bottom holding the block at the end
Tension stays for the most part the same as last years, except that the bend in the two tension pieces is more when you connect it to compression, however once a sufficient amount of weight is put on the bend in the tension pieces end up straightening out.

[scioly2345]

wait what do you mean by trapezoid?

To have a legal boom, I would say most people this year take their 2019 design and widen compression at the wall (satisfying the 8 cm rule), and they narrow it down towards the distal end (satisfying the 5 cm block). This narrowing makes the compression look like a trapezoid like this —> \ / <— the top being against the wall and the bottom holding the block at the end
Tension stays for the most part the same as last years, except that the bend in the two tension pieces is more when you connect it to compression, however once a sufficient amount of weight is put on the bend in the tension pieces end up straightening out.

—-> \ / <—-

[MadCow2357]

wait what do you mean by trapezoid?

To have a legal boom, I would say most people this year take their 2019 design and widen compression at the wall (satisfying the 8 cm rule), and they narrow it down towards the distal end (satisfying the 5 cm block). This narrowing makes the compression look like a trapezoid like this —> \ / <— the top being against the wall and the bottom holding the block at the end
Tension stays for the most part the same as last years, except that the bend in the two tension pieces is more when you connect it to compression, however once a sufficient amount of weight is put on the bend in the tension pieces end up straightening out.

Wouldn't the tension members be on an angle then? Correct me if I'm wrong, but if you wanted the tension members to taper in, that'd probably bend them enough for breakage.

[scioly2345]

wait what do you mean by trapezoid?

To have a legal boom, I would say most people this year take their 2019 design and widen compression at the wall (satisfying the 8 cm rule), and they narrow it down towards the distal end (satisfying the 5 cm block). This narrowing makes the compression look like a trapezoid like this —> \ / <— the top being against the wall and the bottom holding the block at the end
Tension stays for the most part the same as last years, except that the bend in the two tension pieces is more when you connect it to compression, however once a sufficient amount of weight is put on the bend in the tension pieces end up straightening out.

Wouldn't the tension members be on an angle then? Correct me if I'm wrong, but if you wanted the tension members to taper in, that'd probably bend them enough for breakage.

Tension bend is inevitable with my design at least, but they don’t break (bass usually stops it). Would it break if the tension was balsa? I don’t know, probably. Do I like the bend, no. It’s not ideal. I’ve actually been gluing tension of the inside of compression instead of outside (which makes the bend less bad).

[JonB]

wait what do you mean by trapezoid?

To have a legal boom, I would say most people this year take their 2019 design and widen compression at the wall (satisfying the 8 cm rule), and they narrow it down towards the distal end (satisfying the 5 cm block). This narrowing makes the compression look like a trapezoid like this —> \ / <— the top being against the wall and the bottom holding the block at the end
Tension stays for the most part the same as last years, except that the bend in the two tension pieces is more when you connect it to compression, however once a sufficient amount of weight is put on the bend in the tension pieces end up straightening out.

Wouldn't the tension members be on an angle then? Correct me if I'm wrong, but if you wanted the tension members to taper in, that'd probably bend them enough for breakage.

I agree that most teams will use a similar design as last year, just tapered (as stated above). This will put a little of a bend in the connection between the tension and compression piece, but we have also not seen this as a severe issue. Eventually, if the bass tension pieces are too thin, they will break, but you just have to find the minimal thickness that can be used in this situation and still support the full load. The severity of the angle will also depend on how the tension pieces connect the structure you are using to connect to the hook.

[dankdecidueye]

How should I build my trusses? I’ve tried making one pice then sandwiching it between two short ones to look like X. Is this optimal or are there better ways? Also, how many of these X parts should I have at minimum?