I have this even numbers i input!

Edit: that works with your 4 & 1 ! (or 5 & 2)

So seems there is an error when diameters & thickness are not compatible!

Hi Pilou, you've entered in invalid options there.

You're specifying an outer diameter of 5:



That means your thickness value needs to be less than 2.5 :



- Michael

Yes seems that.... :)

So maybe an alert message will be more friendly! :)