Hi Brian,

For this case, I would recommend using Construct / Revolve instead of sweep - it's generally the tool to prefer when you want something that looks like the result of a lathe tool.

Select just one of those rail curves, then run Construct / Revolve, then pick the axis line down the center as the revolve axis and that should build the shape you want I think.

For fillets, I would recommend selecting the curve and running Fillet on the curve first before doing the Revolve, that way all your fillets will be in place already when you do the revolve.


For sweep, the funny oval result is due to the "Maintain height" option which makes the profiles stretch out in one direction along the rails. Uncheck that for the sweep to get uniform scaling which would give you the sweep result that you want here (but again Revolve is better).

A scaling rail is meant to be a smooth curve without any sharp corners in it, so that definitely won't work, and especially one that has a kind of "cliff" with respect to the regular rails is not good, see here for some more info on that: http://moi3d.com/forum/index.php?webtag=MOI&msg=1807.7

Over here I actually couldn't see the missing left-hand bit when doing a 2-rail sweep... Could you maybe show what you mean by that?

- Michael