I didn't know you could scale a cylinder like that. It's handy to know. I don't know how to do that in ruby though - I tried scaling all 24 faces in the x,y axes using the centre of the cylinder, but unfortunately that didn't work. I also don't know why the model gets corrupted when I run the script and not when others do, I get the same results in 2013 Pro too. Maybe its a Mac issue. If you have any more ideas, let me know, otherwise I'll just have to live with it