Cantilever Tower: How To

The Cantilever Tower is essentially a tower and crane designed to hold a certain amount of weight. For our next project, the Cantilever Tower will be made out of Balsa Wood, and you may only have 240 inches of material. You may laminate (glue two pieces of balsa together face to face) once, and you may not excess glue. Design and especially, construction is everything in this project.




To start your cantilever tower, you will need to procure the right amount and size of balsa wood. For our project, we may not use any larger than 1/8th by 1/8th balsa wood. The length will actually vary, but really will not exceed 12 inches. An x-acto knife will be your tool of the trade: a really brand new and sharp one will cut through the balsa wood like butter, accuratly almost everytime without splitting it. When you cut your balsa wood, it is ok to rest a finger on the non sharp edge of the blade and help push, but do it lightly, and be careful (Responsibility kids, cut your finger I am not liable). If you feel uncomfortable with knives, then see-saw it like a saw carefully and slowly until the piece is cut.


I recommend saving every bit you cut off, because you get only so much of it, and you never know where and when you could use a little more wood. My preferred method of construction is to tape two pieces of graph paper together, and draw a 1:1 Scale (actual size) of the Cantilever. It should fit on the paper. When that is done, tape it down to a table and make sure the paper is as flat as possible. Now use wax paper to cover over that (less mess, and it will save your blueprint). If you accidentally cut too much with your x-acto knife, put a new patch of wax paper on top and remove the old piece.


I strongly suggest building the tower in two halves, vertically. Structurally, the Cantilever Tower will be weaker if you build the tower, then attach the arm. Build the tower and arm as one, and attach the two halves. To construct your Cantilever, cut the pieces first, then glue them all together after the cutting is done, to ensure quality and accuracy. QUALITY AND ACCURACY! BOTH ARE ESSENTIAL. Your crane will withstand more stress when built better.



Remember that the weight will want to pull down on the tower, and rip about where the arm and tower meet. Technically, the weight wants to rotate the arm off of the tower, this is called torque. Torque is the same principle behind spinning wheels in place before a car accelerates: except the wheels will not come off the axels (like they want to, due to torque). The only way to reduce the force of torque is to have an efficient design. You want to send stress to other parts of the entire crane that will not receive much stress. You also want to distribute the weight, NOT focus it all on one point. If you focus any part of the crane, at any point into one stress point, that is where the crane will fail.


I am currently building side A of the crane. Will let you know how far I get when I get there.