# how to curve a beam?

Posted by Replace
 how to curve a beam? January 15, 2020 11:15AM Registered: 12 years ago Posts: 861
I want to build new batteries for my drone.
After having welded the Li-ion cells in the proper config, I want to place them in a square container. It will be 6 battery cells stacked on each other.
So that will be a beam shaped object. (subtract a cube from a cube will do the math)

However, the remaining box must be slightly curved to follow the shape of the drone landing gear, to which the boxes will be fixed.

Any help in bending a beam , of the resulting box ?

Thomas

www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)
 Re: how to curve a beam? January 17, 2020 03:32AM Registered: 9 years ago Posts: 590
I tried to understand what you are trying to do, but without further information (e.g. photos of your drone or you current battery pack) I don't think it's possible to give you the desired help.
 Re: how to curve a beam? January 17, 2020 11:43AM Registered: 12 years ago Posts: 861
ehh.. imagine that you have the outer part of a match box.
Now try to bend it alongside a football. (not possible, but as a thought experiment)

What remains is a hollow square beam with a bend according the outer perimeter of the ball.

Now scale up the result to the dimensions of 6 lipo 18650 cells stacked upon each other along their long sides and put it in the box.

Does this help ?

www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)
 Re: how to curve a beam? January 18, 2020 03:04AM Registered: 9 years ago Posts: 590
Is it something like this that you are looking for?

This one is composed of 3 sections with [angle,radius] pairs [20,200],[-25,450],[-180,150].
If you only have one section with a constant radius, you can just with a difference of two rotate_extrude(...)square(...).
 Re: how to curve a beam? January 18, 2020 06:55AM Registered: 12 years ago Posts: 861
Yes,

So I just rotate extrude a square ? and than make it hollow ?

Thanks I will try.

www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)
 Re: how to curve a beam? January 18, 2020 07:09AM Registered: 9 years ago Posts: 590
As I only have version 2015.03 of OpenScad, I can't (yet) use the new angle=... parameter of rotate_extrude(). Here is how I did the example below:
```\$fn=180;
difference(){
rotate_extrude(angle=3)translate([200,0,0])square([24,24]);
for(a=[0,90])rotate(a) translate([-300,0,-1])cube([600,600,26]);
translate([0,0,3])rotate_extrude(angle=3)translate([203,0,0])square([18,18]);
}```

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