Designs

[nejanimb]

A ruler, a compass, and a piece of paper?

[old]

The 8.0 cm hole is not part of the tower, it is a hole in a testing jig, or an imaginary circle, through which the top portion of the tower must be capable of passing. At the national tournament the tower will not be allowed to touch the circle in the jig, so don't build a force-fit. As always, it is not wise to build devices so close to the maximum sizes that you need an interpretation from a judge, you should allow a little extra clearance. There will be no problem setting the testing block on the top of the tower, you can build the top as narrow as you wish, provided the 1/4" eyebolt shank fits through it, and provided there is room for a chain below that.

It appears that the scoring scheme was revised during the summer to get the size of the numbers more reasonable, changed from grams^2/grams, or units of grams. In the 2006/2007 rules, efficiency was a unitless number. Now score is in units of Kg^2/g. The scoring scheme is idiotic.

Bob Monetza
Grand Haven, MI

The score is still a unit less number. The grams both cancel out, whether they are kilograms or grams or milligrams.

[rjm]

Last time I checked, g^2/g = g, not 1.

I suppose we could multiply by a scoring factor of 1/g with a numerical value of 1 to make it look right. Kg^2/g could reduce to g or Kg, but getting the order of magnitude right with the units is more confusing.

As you may note from the rules, the score is no longer referred to as efficiency, as in how many times its own weight that the tower can support, it is simply a score, so the units could be anything.

Bob Monetza
Grand Haven, MI

[SLM]

Here is a link to an online tool for calculating forces in 3-D (space) trusses: http://www.nexote.net/nexote/3D%20Truss ... 0Notebook/. You might find it useful for designing towers. The website permits users to ask, if needed, for help for using the tool.

If you want to model your tower as a two-dimensional structure, then you can use either http://www.nexote.net/nexote/Structural ... 0Notebook/ or http://www.jhu.edu/virtlab/bridge/truss.htm to calculate member forces.

[lllazar]

Here is a link to an online tool for calculating forces in 3-D (space) trusses: http://www.nexote.net/nexote/3D%20Truss ... 0Notebook/. You might find it useful for designing towers. The website permits users to ask, if needed, for help for using the tool.

If you want to model your tower as a two-dimensional structure, then you can use either http://www.nexote.net/nexote/Structural ... 0Notebook/ or http://www.jhu.edu/virtlab/bridge/truss.htm to calculate member forces.

It says i have no permission to use this - wat tab am i supposed to press on the left?

[SLM]

Here is a link to an online tool for calculating forces in 3-D (space) trusses: http://www.nexote.net/nexote/3D%20Truss ... 0Notebook/. You might find it useful for designing towers.

It says i have no permission to use this - wat tab am i supposed to press on the left?

If your Web browser is Javascript-enabled and supports Flash, when you access the page you should see:



Then, click on:
"Geometry" to define the geometry of the tower,
"Supports" to specify the tower's supports,
"Loads" to indicate the location and magnitude of each applied load,
etc.

[reachgeek]

want this event so bad, however i might not be best suited for the event

[phillies413]

I have a question:

when you build the sides of the towers, do you build 4 sides and then put them together, or 2 sides and then use cross bracing to connect those sides? Sorry if this is a really dumb question, but I'm new to tower building....

[iYOA]

well, i build 2 independent sides and lay them side by side on my tower design template +use cross bracing to connect them so that i get 4 sides. However, i am finding that the base usually becomes wobbly. idk if this is just lack of practice or a bad building method.

[Bubba1960]

Here is a link to an online tool for calculating forces in 3-D (space) trusses: http://www.nexote.net/nexote/3D%20Truss ... 0Notebook/. You might find it useful for designing towers.

It says i have no permission to use this - wat tab am i supposed to press on the left?

If your Web browser is Javascript-enabled and supports Flash, when you access the page you should see:



Then, click on:
"Geometry" to define the geometry of the tower,
"Supports" to specify the tower's supports,
"Loads" to indicate the location and magnitude of each applied load,
etc.

Wow thanks! That notebook thing is great!