Currently making one myself for my hulkbuster project

https://simplymaya.com/forum/showthre...threadid=41441

1 Create cylinder > open channel box
2 change Sub caps to 0 and subdivsions axis to 12 (Reading the tut it tells you 12 but he is using 20 - bit misleading)
3 Select the face on bottom and top and then select Edit Mesh > Face > Extrude. Here click the blue box which will activate the middle box
4 To match the tut scale it in, then press "G" to use it again or just use the Edit Mesh > Face > Extrude again.
5 Now use the split poly tool to connect the faces to quads - this is how I would do it
6 This is closer to the tut way of doing it, but again I did it on 12 sides (like he said to do it) not the 20 he has used.