Loft Tangency

[djohannesen]

I have searched the forum for how to perform lofts from square to round profile.

 

I still can't remove the twist which occurs & 'corrupts" the finished loft.

 

Can anyone explain a bit more clearly how this is achieved?

 

Thanks,

Davo

[Guest IronKevin]

Select the Loft at the IntelliShape level.

Right-click and choose Edit Match Points.

Click the numbered square of the cross-section containing the match point you want to move.

Drag the match point to the desired vertex.

 

IK

[Cary OConnor]

If you are lofting from a square to a circle, there are somethings you need to look at. First, a square has four vertex points and the circle has none (or one really). Anyway, IronCAD will split the circle to have four points to make the match points in the loft. This is what is causing the twist in most cases. To avoid this, split the circle manually using the 2D split command in the sketch. This way, you can control where the connections will match too (add you can use the previous post suggestion to change the match location if needed). Also, make sure that the profiles in the loft are in the same direction (make sure the positive is all pointing the same way otherwise you will get twist).

Hope that helps.

Cary

[Guest EricFoy]

In my limited lofting experience (all with older versions of IC), I have generally had success by making sure that all my cross-sections have the same number of verticies. To go from a circle to a square, as Cary mentioned, you can split the circle up into separate arc segments. You can then custom-tailor the intermediate blending by scooting the arc endpoints around. Also, I have had some success by using splines instead of lines & arcs, and vice-versa. It's all a bit tedious, but do-able. For complex lofts (and complete control over things like tangencies, fairness along arbitrary axes, etc., Rhino is an excellent tool that works very well with IronCAD and isn't terribly expensive.

 

The IronCAD-Rhino combo is a killer combination. Both programs have their respective arenas of excellence, and neither pretends to do what the other was intended for. With those two Apps, you can outrun ALL other 3D CAD systems!