How tall....

canadianbrix

Our son has to create something tall for science class (grade 7) to examine structural stresses and physics (a variation on the match-stick bridge project) out of any chosen material from home.  So, naturally, he is planning on using Lego.

We have been going straight up with 4 stud by 4 stud squares using 2x4 bricks and reach the ceiling easily enough.  It wobbles and leans but falls if gets any external pressure.  Clearly a fatter column will do better, (already started) as will a heavy foundation, but buttressing is not allowed.  We figure the next section in the study unit will be about improving the towers so we need to leave some room for improvements in versions 2a, 2b, 2c.....

I am sure there are lots of Bricksetters with experience and he would love to hear about past efforts.  If you could share stories and projects it would be great.

Also, and perhaps more important is finding a reliable resource text.  An engineer buddy couldn't find anything in his resources specific to Lego :-).

Thanks in advance.

MattDawson

If I might be so bold, having done a little research into this for personal purposes, to save bricks and preserve internal strength build a hollow tower with internal bracing - so that when you look from the top it forms a Batternberg cake style shape. That way there's still plenty of strength from the internal bracing to support the extra weight.

Also, depending on the height,  go for a 'stretched pyramid' style - this base, thin top.

Remember that the further down the tower, the more weight it has to support - which is why tall, tower buildings have a thicker base structure/columns compared to the top.

GallardoLU

sounds like there are 2 issues at play here. how to make it more stable but also limit it's height. Lego in vertical construction is insanely strong. it's also relatively light so external forces (as you know) can play a big factor in a tower's life. a simple 16x16 hollow column (also using only 2x4s) for example I built a few years ago it was stable and able to be transported in 1 piece at 6 feet tall. placed in a location where little could touch the structure we were able to place 3, 6 foot segments together for an 18 foot hollow tower. there was definitely some movement at that height just from air movement.

seeing as this is a class project I would try for the largest vertical tower you can build and transport without disassembly for the first one. this should allow you to add buttresses later (if they allow them, it sounds like they might) or a tapered structure. both will add more height easily.

lastly take a look at some of the world record towers built over the years. should give you an idea or 2 for construction.

CCC

I'd go with 8*8 columns, but hollow. Decent height and strength but more brick efficient. Although as it is a school project, I'd be tempted to do just a 2*2 tower (maybe as well as a stronger one). For the reason that it will topple more easily, and therefore some fun.

canadianbrix

Great ideas.  Thanks for the comments.
He found the theoretical max height before brick failure really cool.  That would be beyond a class project :-) 
It seems that it will be a hollow 8x8 column in two 5 foot tall sections for transportation for stage 1 of the class on Wednesday.  A lot of random pieces have been incorporated and many other structures and buildings have been robbed of 2x bricks.  It is first science project that has illicted so much passion in our otherwise somewhat lazy son !