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3dopenscad

Given dimensions are different on 3D printer

I draw a small cap in openSCAD and defined the dimensions in 'mm'.

When I export the part as STL and open it in the 3D printer's software, the part is almost double in size.

here is the part's code:

difference() {
    cylinder(h = 15, r1 = 35, r2 = 35);
    cylinder(h = 12, r1 = 32, r2 = 32);
    cylinder(h = 50, r1 = 3, r2 = 3);
}

The render shows the inner edge around 32mm, and outer around 35mm. But 3D printer shows 70mm radious. I am started to use openSCAD a week ago and I did not have any ratio issues with previous test prints (cube, pyramid, etc). This is the 1st real life I designed and I have a ratio issue. I can scale down the model in 3D printer software but I would like to know the reason behind it, so I can design future stuff accordingly.

Edit: I scaled down 50% and printed. The outside radius was correct, but all other dimensions (the height, wall the thickness) were also 50% scaled down. So only the outside radius was incorrect at the beginning.

Render in openSCAD

Solution

  • It's exactly 50% too wide?

    Remember that r stands for radius, and that radius is half of your diameter.

    It sounds to me like you filled in the diameter values when you meant to fill in the radius values.