Lego air plane flaws ?

Question

i designed lego air plane and the back always tips over it ownt stay on the 3 wheels it normally hays the front sticks up and the back falls towards the table what can i do ? the whells are in even places..

Answer 1

There are a few ways to fix the problem, but some are more difficult than others!  Here are some fixes that may work:

1) Make the "legs" for the landing gear shorter in the front and longer in the back.  This may not work if your plane is too unbalanced, but it may just be enough.

2) Place the rear wheels further back.  I imagine that they're under the wings, so try and make them as far back on the wings as you can.

3) Add more bricks to the front to make it heavier, and/or remove bricks from the rear to make it lighter.  This may mean filling in hollow sections or making areas more hollow.

4) Make the plane longer in the front (the part in front of the rear wheels).

To make sure that you've got good balance, here's how you can test.  Find the "center of gravity".  Do this by (very carefully!) resting your model on a single finger that runs underneath the airplane.  Find the spot where you have to put your finger such that the plane will balance perfectly on your finger.  That's the center of gravity.

Now, with an airplane with 3 wheels, see how the 3 wheels make a triangle?  You want your center of gravity to be somewhere inside the triangle.  If it's outside the triangle, it will fall over.  And if it's close to the edge of the triangle, it MIGHT fall over.  But the closer it is to the middle, the more stable it will be.

DaveE