Spline point tangent angle problem. 2

[Nexim]

I'm having a problem with a sketch I'm doing in SW 2007. Please see the image attached. Basically, I have a spline, and a vertical centerline, and I want to mirror the spline about the centerline. However, I want it so that at the intersection of the spline and centerline (1st spline point) the tangent is horizontal. (Such that the original and mirrorred splines smoothly connect).

You can see where I have selected the spline point, and tried to change the tangent angle. The only way it is letting me change the actual angle is by manually rotating the spline by dragging one of the handles with the mouse. When I try to type a number into the box, as soon as I click back out of the box (expecting to see the change), the number just goes back to what it was again.

Being a perfectionist, this is driving me mad. I need to get the angle at 180', and 179.78...' isn't good enough.

Does anyone know why it's not letting me input the angle?

Thanks

 

[TheTick]

Use sketch constraints. You cn constrain spline points perpendicular or tangent to lines. Constrain the spline endpoint perpendicular to the symmetry line, or create a horizontal line and constrain the spline end tangent.

 

[CorBlimeyLimey]

Do the constraints show that the solid black line is horizontal, and that the spline and line are tangential?

 

[Nexim]

By sketch constraints do you mean the dotted lines that appear, showing you how a sketch entity can align with other entities, when you move the cursor around? If so, I don't get any of them when I move the cursor, which is why I created the horizontal line, hoping that one would appear, but it hasn't. If I move a spline point in line with it, the dotted line appears, but nothing appears when I'm trying to get the tangent of the curve at that point parallel with it.

 

[CorBlimeyLimey]

The dotted lines are actually "Inferences". i.e. they just infer what the constraint will be if attached to. The actual constraint is what is shown in the LH side panel when an entity is selected.

 

[TheTick]

If you don't understand what sketch constraints are, you need to dial back a bit and learn those before you set about spline-wranglng.

Constraints are things like tangent, parallel, perpendicular, conincident conditions defined by the user, that determine how sketch entities relate to one another.

 

[CorBlimeyLimey]

If you select two entities, the constraint manager (LH side panel) should appear, and the required constraint can be selected.

 

[Nexim]

Thanks, managed to fix it now.