Towers B/C

[cheese]

Not really, you don't want to run out of time so don't go super slow.

But also, don't start really fast because you don't want any sudden force jerking your tower or anything out of position.

We start off slow and get faster as it goes on.

[Samantha]

Hello!
I've built many towers with my partner and we are at an impass where the 'cage' part of the tower that has to be 8cm always leans when we test it. We don't know if the connection from the cage to the 'bridge part'/ base or if it's something wrong with the cage itself. But the cage and the bridge don't break themselves. Only the connection. Would really appreciate any help!

[DarthBuilder]

I’m so sad right now because I built a tower that was 5.8 grams with bonus hoping to get a 2k plus score. But maybe walking down the stairs? Something chipped off in the bottom because it was pretty uneven. I got a 1300 efficiency.
Hopefully at Solon it’ll work out

[DarthBuilder]

Turns out I got second at the crystal lake central invite.

[TowerPro+2500]

What is the benefit/non-benefit of a heavier density of balsa wood? Any amazing techniques for building towers?

[Balsa Man]

What is the benefit/non-benefit of a heavier density of balsa wood? Any amazing techniques for building towers?

Take the time to read through all the info that's here. Very detailed discussion of exactly what you're wondering about; detailed info and data, and explanation of how to use it.

[JibrielS2019]

Delete

[JibrielS2019]

This is my new account (old one was darthbuilder).

yesterday at the CLC invite when I was pouring sand all the sand went straight to one side of the bucket so it was leaning. Was it me or was there something wrong with the stand? this has not happened to me before.

[jinhusong]

Hi,

I convinced my son and his partner to build tower with 2 part jig first so that they will appreciate the one-jig approach more later.

They took 2 hours to build the chimney, 2 hours to build the base and 3 hours to put them together.

This is a snapshot I took before they trim off the top close to the top ladder.


The 1/8 stick picking thresholds are from Balsa Man’s spreadsheet. Base with 5 intervals and chimney with 7 intervals. The base they used 1/8 stick with BS around 40g (@36 inch) while the threshold is 21g.

The tower held 7.13 kg in Golden Gate invitation (12th place). While I was there, I saw similar towers also hold around 8kg (one is from Hawaii). They all crashed at the base. By similar, I mean all X with 5 intervals for base.

From video, my son told me that the second X from bottom bent inside gradually and then snapped. When they built, I knew they oriented the legs to bend outward.

The materials are from limited left overs.
============
Chimney leg: all 17 inch cut from BS 36 at 36 inch (threshold 29 from spreadsheet)

# weight(g) BS(g) calculated BS(g) at 36 inch
1 .58 117 26
2 .59 160 35
3 .56 130 29
4 .64 180 40
5 .61 163 36
6 .55 133 30
7 .58 160 35
8 .60 180 40

I believe they pick #2, #4, #5, and #7.

Chimney brace: strip 1/16 X 1/32 from 1/32X3X36 sheet with 6 grams
==========
Base leg: all 9.875 inch cut from 36 inch with BS=39 (threshold 21 from spreadsheet)
# weight(g) BS(g) calculated BS(g) at 36 inch
1 .37 460 34
2 .39 540 40
3 .44 660 49
4 .40 520 39
5 .40 630 47
6 .40 540 40
7 .45 640 48
8 .42 555 42

They picked #2, #4, #6, and #8.

Base brace: strip from 1/32 X 3 X 36 with 10 grams. Their other sheets are so heavy > 16g, I convince them to cut wider from the 10 gram sheet for the lower X.
2 lower X: 3/32 X 1/32 strip
3 upper X: 1/16 X 1/32 strip
===========
I recommend them to scale the calculation from their own data and try another all X base with 7 intervals. Also try a ladder plus X with 4 intervals.

============
Many thank for Balsa Man for the spreadsheet and the formula. Also thanks for the guy recommended for the glue applier built with 0.2mm music wire and a stick. I cannot find the article anymore. Now they use way less glue and no more sticky fingers.

Jinhu

[megan_scioly]

Is there any regulation for the size of the S hook and the chain? What would be a good estimate for the chain and s hook to be? Thanks.