I an trying to make a wheel using array.It all goes well until I use the subdivision surface modifier. Please have a look at my image for reference. What am I doing wrong? When I turn off the modifier everything is perfect. I have attached the blend file.
rotiform roc.blend (562 KB)
Modifiers are applied from top to bottom in the modifier stack so their order is important.
The Array modifier needs to be above the subsurf modifier so you subsuf an arrayed object and not array a subsurfed object
rotiform roc2.blend (112 KB)
Might also want to consider mirroring 1/10 first, then array. That way both sides of each hole stays uniform, and vertices line up for the array.
Also, it looks that you divided your modelling of the circular part of the rim in parts?. You need to merge the vertex so they stay together… otherwise the smooth will never work as you want.
Thank you. Learn something new everyday 
I tried to use scale and (, .) to make sure they are uniform but your way is even better. Thanks for the tip.
