Torus creation in 2.8 I really want to like 2.8 but every time I get into it,  I find something I don't understand. Today is creating a torus. I want to create a jump ring for a piece of jewellery. I want an inner radius of 1.5mm and an outer radius of 4.7mm, When I create the Torus, the smallest I can make either radius setting is 10mm for either of them. Set it to 1.5, you get 10. Set it to 3, get 10. Interestingly, setting it to 10 and 10, gives you a torus with an internal radius of zero not 10. What am I doing wrong?
You first need to change your working units because this operator won't let you input values &lt; 0.01 meters (10 cm) in the fields if you keep working with meters.



The easy way



The hard way

For the sake of maths ..?

So, the major radius is the radius of the middle section of the torus, and the minor radius is the radius of the circle section of the torus if you cut through half of it radially. 

We have 


RM : Major Radius
rm : minor Radius
Re : Exterior radius (in your case, 4.7)
Ri : interior radius (1.5)


Ri = RM - rm

Re = RM + rm

&lt;=> RM = 4.7 - rm = 1.5 + rm

&lt;=> rm (minor radius) = 1.6 and RM (major radius) = 3.1

But you need to set your units correctly for this small a model.