Page 9 Modeling a Tank: Turret

Select just the upper curve of the 2 curves selected in the top view and delete it.

Select all the cannon mount and the projected curve except the curve inside the turret and hit Loft and use the 'Straight sections' and 'Rebuild with 12 points' options.

Select the new cannon mount surface and hit Cap.

Turn on the 'hatch curve' layer. Select the hatch curve and hit Extrude 'Cap=Yes' and give it a 30 unit height.

Hit FilletEdge and give the top edges of the hatch a fillet 'Radius' of 15. Result shown below.

Hit Explode with the hatch selected and Delete the bottom surface. JoinSrf the hatch.

Note: You can leave the bottom face on the hatch and UnionBoolean it to the turret but although you won't see any extra geometry it will in fact create more geometry when turned into a mesh. I don't recommend using UnionBoolean.

Turn off all of the curve layers and turn on the 'turret detail curves' layer and zoom in on the area shown below.

These are 3 curves to create a side hatch that's bolted to the turret. Select the vertical line shown below and hit ArrayCrv and when prompted to 'Select path curve:' select the oval curve. In the 'Array Along Curve Options' dialog box use 'Number of items' 16 and for Style use 'Freeform.' Before doing anything else hit Delete to get rid of the original curve so you don't have 2 curves right on top of each other.

Select the curves shown below and hit Loft using the 'Normal' style, 'Closed loft' and "Do not simplify" options. Hit Delete to get rid of the unwanted construction curves.

The Sweep1 command could have saved some steps and just selected one of the 'cross-section curves' and sweeping around the oval as the 'rail curve' but that would have created some extra geometry. The difference is shown below.

Loft (above)