Towers B/C

[sciencepeeps]

Should the loading block be in contact with the very first ladder? Or should it only contact the four bits that extend off each leg past the first ladder?

Nevermind, this was already answered! Can anyone explain why though?

Well, most people design towers where the weight would ideally be distributed evenly between the four legs. In order to make sure this happens, you would want to put the loading block (the weight) on the legs directly. If the loading block is placed on the ladders, not all of the weight would be placed on the legs. i learned this the hard way

[Balsa Man]

Thanks Balsa Man.

I have been reading the posts and gathered that 1.5 gr / 36" stick would be good enough to hold 15 kgs (with X braces). Since the wood I have is high density 3/4 strength of 1/8" would work for me I guess. Understand that BS will depend on how I brace the columns as well. Now if only I can find the ideal interval for bracing..

Well, at the risk of sounding like a broken record, what can I say, the info, in detail, to answer that question is just sitting there waiting for you to come digest it; how to figure out the bracing interval, for B and C towers, using ladders and Xs bracing. The most recent version is 2 pages back, ~middle of pg 37...... You're going to have to check the BS of sticks you are thinking about using, to see, then follow the directions do the calculations. Enjoy, and put it to good use
Good luck.

[Balsa Man]

Should the loading block be in contact with the very first ladder? Or should it only contact the four bits that extend off each leg past the first ladder?

Nevermind, this was already answered! Can anyone explain why though?

Well, most people design towers where the weight would ideally be distributed evenly between the four legs. In order to make sure this happens, you would want to put the loading block (the weight) on the legs directly. If the loading block is placed on the ladders, not all of the weight would be placed on the legs. i learned this the hard way

Right-on, fd4- wish there was a gold star icon - you get the gold star for the day. The other reason, as discussed previously, is you want room to sand leg tops even for full 4 point, level contact, without sanding into the ladder (which could fatally weaken it).

[Balsa Man]

Should the loading block be in contact with the very first ladder? Or should it only contact the four bits that extend off each leg past the first ladder?

Nevermind, this was already answered! Can anyone explain why though?

Well, most people design towers where the weight would ideally be distributed evenly between the four legs. In order to make sure this happens, you would want to put the loading block (the weight) on the legs directly. If the loading block is placed on the ladders, not all of the weight would be placed on the legs. i learned this the hard way

Oops, correction - Right-on, sciencepeeps- wish there was a gold star icon - you get the gold star for the day. The other reason, as discussed previously, is you want room to sand leg tops even for full 4 point, level contact, without sanding into the ladder (which could fatally weaken it).

[dholdgreve]

So I was watching Towers at a recent Regional. Unless I saw this wrong, a supervisor had his test base sitting there, got out a circular piece of paper (dia ~29 cm) with a ~20 x 20 cm hole in the middle, laid it on top of the test base, and traced the circle onto the test base. I thought this was odd because if the circle was exactly 29 cm, the resulting traced outline by definition had to be more than that. If he had calculated the exact width his pen mark would make and made the template small enough to result in a 29 cm circle when traced, well, then, good for him, but my kids' tower didn't fit the bonus circle even though it did the night before on our base (which I confirmed via ruler today). Again, I could have misinterpreted what he was doing, but I have two questions:

1. Is there anyway that circle could have been accurate?
2. Are the kids allowed to ask the circle to be measured?

Just my two cents...
In football the sideline is considered out of bounds... In soccer, the line is in bounds... Who is to say that the judge is not using the inside edge of his line in determining? It could be that as long as the legs sat on the line, but not inside them, they are good to go...
I already had our tower table built from previous years with a 20 cm x 20 cm square cut out of the center of the table, then a sheet of 1/4" plywood attached under the table with a 5 cm diameter hole for the chain to drop through located in the center of the plywood. I cut a 20 x 20 square that fit tightly in the table cut out, drew diagonals through the square to locate dead center, then took a small piece of wood and drilled a small hole near one end and measured 14.5 cm from it and drilled another hole. I fastened the end through the first hole with a screw, then using a pencil, scribed a circle through the second hole and removed the entire block.

As part of the check-in procedure, we also have a 29 cm circle drawn in autoCAD, then plotted full scale. If it's good enough to scale drawings from, it's good enough for towers.

As for your last question, I think kids should not only be "allowed" to ask questions, it should be their responsibility to. Science Olympiad does a great job at the obvious... teaching science. Turning kids into adults. It teaches kids how to converse and deal with teammates, adversaries, coaches and other "People of Power..." i.e. Event Coordinators. It teaches them how to resolve potentially contentious situations efficiently and fairly (or should). If your kids are not learning how to address Event Coordinators in a respectful but communicative way, perhaps they could / should be learning more than just the science... Teach them the correct way of respectfully asking for an arbitration or appeal. (clomp, clomp)... I'm ok... just tripped climbing off the soapbox!

[CrypticBuilder23]

So I was watching Towers at a recent Regional. Unless I saw this wrong, a supervisor had his test base sitting there, got out a circular piece of paper (dia ~29 cm) with a ~20 x 20 cm hole in the middle, laid it on top of the test base, and traced the circle onto the test base. I thought this was odd because if the circle was exactly 29 cm, the resulting traced outline by definition had to be more than that. If he had calculated the exact width his pen mark would make and made the template small enough to result in a 29 cm circle when traced, well, then, good for him, but my kids' tower didn't fit the bonus circle even though it did the night before on our base (which I confirmed via ruler today). Again, I could have misinterpreted what he was doing, but I have two questions:

1. Is there anyway that circle could have been accurate?
2. Are the kids allowed to ask the circle to be measured?

This is actually exactly what I did to draw the bonus circle on my school's test base at the beginning of the year, although my paper was printed out in four pieces and taped together, and I made sure to account for pencil line width. You can probably ask that the circle be measured, but probably nothing will come of it even if it's discovered to be inaccurate (at least that's what would happen where I am, not sure how your tournament will respond).

At my regional tournament, our tower did not qualify for bonus despite us specifically designing it for that purpose. We asked what dimensions the circle was and the guy (he didn't know how to run towers at all) said 29 cm. We brought in somebody who knew what they were doing, and we realized that the circle had a diameter of like 32 cm! Needless to say, we got the bonus. It always helps to ask!

[fdf4]

What density should bracing be at for 24" sticks at 1/64 x 1/64 and 1/16 x 1/16?

[fdf4]

What density should bracing be at for 24" sticks at 1/64 x 1/64 and 1/16 x 1/16?

Sorry, I mean 36" strips

[Balsa Man]

What density should bracing be at for 24" sticks at 1/64 x 1/64 and 1/16 x 1/16?

Sorry, I mean 36" strips

Sorry, but I can't figure out what you're asking.....

[fdf4]

The numbers I gave were just measurements I'm most interested in using, but basically, how should I find what density of wood to use for bracing and the different lengths?