when creating a relatively big (r=1, L=20) in folder creating 3d grids with simple meshes (using cylindrical coordinates), there is a sort of plane between the 0 and 360 degreees, if i merge them the cylinder is perfect. However, I want to make a (r=0.00002 and L=0.0008) cylinder and when I merge the cylinder it collapses.

How can i make a small cylinder without any errors? Thanks

There is a value "tolerance", which must be set smaller than the grid spacing

...And the other way is to use different units when creating the model, not meters, and then speciying the geometry scale factor