5

What is the strongest LEGO box structure?

I am going to build a LEGO computer case. Different from Mike Schropp and greenyouse, I am planing to build an upright case.

(This is a general "strongest LEGO structure" question. Using the structures in building the computer case is just an example of applications.)

To make it more challenging (and more perfect), the case will have handles (like this type) for carrying the whole thing around, and it will have "legs" (like this bar type) to lift the whole case up for ventilation.

For better reference, here is the coordinate notation:

enter image description here

There are 4 parts (for now I can think of) in the case which has to encounter different types of strength challenges:

  1. The pillars (Red)
  2. The floor (dark grey)
  3. The joints (purple)
  4. The handles (yellow)

enter image description here enter image description here enter image description here

For the white bricks, they do not require special strengths, do they?

FYI, here are the LEGO dimensions:

Horizontal pitch, or distance between knobs: 8mm.

Vertical pitch / Brick thickness: 9.6mm.

The horizontal tolerance: 0.1mm.

Plate thickness: 3.2mm.


Above is the common information across the 4 questions.

Below is the question for this specific part.


(2) The floor (dark grey)

Someone has done some experiences against the effect of weight on LEGO bricks (results at slide 11). From his experiments, the Flemish structure is a clear winner.

Like the pillar problem, I wonder why not stack plates/bricks up along the X/Y axis, instead of the Z axis?

My suggestion is basically the structure of the pillar rotated clockwise along the Y axis, and extending it along the Y axis.

enter image description here

For those who have not read the pillar section yet, this is simply stacking up plates along the Y axis.

Same as the pillar, there is a risk of the plates separating due to the weight. So I make a "doughnut" to secure the plates.

enter image description here

Here is how they look like together.

enter image description here

I assume using longer plates will be better than short plates, because fewer connecting points, lower risk to separate, isn't it? However, in the presentation mentioned above, the result suggests that a mix of long and short plates has the most strength. Does this theory apply to my "Y axis structure"? And how long and how short combinations will be the best?

In addition, in my "Y axis structure", will using bricks instead of plates be stronger?

However, thing is more difficult here than the pillar. It is because the tension is not only pulled along the X axis. Instead, the weight is applied down the Z axis, and tension is all along the X and Y axis. So I assume this structure, when used as floor, will be a lot weaker than used in the pillar.

Please suggest any of your structure ideas which will be the strongest.

  • This seems very broad, and also a near-duplicate of your other question. Perhaps split them into shorter, simpler questions that describe exactly what you want to do like "how do I make a strong box", "how to I add handles to my box". Or combine them into one "how do I make a computer case". The extremely general "what's the strongest structure" is impossible to answer unless you define "strongest". Using mechanical engineering terms there would be best so we don't have to explain those to you. – Ⴖuі Jun 15 '15 at 10:18
2

Just like in the other question, I would recommend a Technic frame with more depth than your original idea and some plating on top of it. This project nicely illustrates how to build stable Technic structures using beams in triangle configurations.

1

This question is amazing and well-thought-out, but it also made me laugh.

Building a LEGO floor? The problems with the structural integrity of any floor are simple, as follows:

  1. The integrity of the walls above; how well they "grip" the floor.

  2. The integrity, if applicable, of the walls below, how well they hold the floor up.

  3. The integrity, or more specifically torque resistance, of the floor.

The structural engineer can now see why this brought out a chuckle.

For a LEGO build, the floor will be placed, inherently, on another floor. Thus, except in multi-story skyscraper builds, neither issue 2 nor issue 3 apply.

The real floor supports your LEGO floor with ease; otherwise it wouldn't be holding you very well.

The only thing to worry about is how good your connections to the upper pieces, (walls,) of the build are. Thus, neither your floor nor your ceiling, (You shouldn't put anything on top anyway, at least not something heavy, will be any trouble. However! Your connection to the sides of the case is very important. If the bottom falls out when you pick the unit up, it's no longer a good day.

TL;DR

The floor itself, provided you don't use a single plate, or aren't holding up real actual cement bricks, will be perfectly fine, you should worry about keeping the walls connected to the base , i.e a dovetail.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.