Boomilever B/C

[cheese]

Yeah I think a lot will be just refining minor parts. I have found that an imbalance in how long your tension beams are can result in crazy twisting.

[TheChiScientist]

Yeah I think a lot will be just refining minor parts. I have found that an imbalance in how long your tension beams are can result in crazy twisting.

IKR!!!!!! AGH!!!!!!!! What other build problems have people faced? Best to address them now vs later.

[cheese]

I think, to a point, you need to be ultra precise on how even your column pieces are as well as your tension pieces. It will be very similar to towers, where if your tower wasn't perfectly level, there will be an imbalance which may cause the death of your boom.

[Cow481]

I think that the angle of the tension pieces compared to the compression pieces is very important and you need to be very accurate with it

[dholdgreve]

Boom has been an event before. In 2014, here were the primary reasons for failures:
Compression Beam failures (Buckling). 43%
Wall Attachment point failures 39%
Tension chord failures (Sear parallel to grain) 11%
Load point failures (Distal end snap offs) 5%
Twisting and torquing due to symmetry issues 2%

If you pay attention to issues relating to the most prominent failures above, you are almost home!

[dholdgreve]

Our first boom build resulted in booms in the 12 to 13 gram range. We have not tested any of these yet,(testing will be on December 1st) so I'm not sure how they will score. Does anyone else have any weights they would be willing to share, as well as what your target weights are?

[Cow481]

I got one around 15g but it held only aroung 5k. I also made one that was somewhere around 8.5 g and it held around 6k. The first one was due to the compression pieces breaking but i was using bad wood to make like a test boom first and the next one was becuase of the wall attachment point but it should be fixed soon.

[LiveMas]

I have read most of these posts, which helped a lot.
I still have few questions:
1) if there is a 2.5 cm between the hook and the test wall, then the boom would have to be at an angle correct? (because the lower base touches the test wall and the upper base is at a distance from the wall, and the loading block should be parallel to the test base)
2) should the bracings for the two sides be on the insides or on the outsides? which will be stronger? (inside meaning on the top and bottom of a sticks, so that when a side is layed flat on a table it is actually flat)

[Unome]

I have read most of these posts, which helped a lot.
I still have few questions:
1) if there is a 2.5 cm between the hook and the test wall, then the boom would have to be at an angle correct? (because the lower base touches the test wall and the upper base is at a distance from the wall, and the loading block should be parallel to the test base)
2) should the bracings for the two sides be on the insides or on the outsides? which will be stronger? (inside meaning on the top and bottom of a sticks, so that when a side is layed flat on a table it is actually flat)

#1 - yes.
#2 - Bracings on the outside are most common, because they're easier to attach and also won't overlap with each other strangely. That said, I don't think there's a definite consensus on strength.

[LiveMas]

Alright thanks!
what size would you recommend for bracings?