dimensioning spline control points

[Willis123]

I have a specific (customer supplied) shape I need to revolve into a solid and I was wondering if there was a way to dimension the control points on a spline. The dimension tool is blind to them. I could put in and dimension reference lines and pick the intersection but what a pain! After digging around, past posts didn't have any great solutions. Is there a better way?

Weren't computers supposed to make design easier and more foolproof? I guess not. I'm still waiting for my George Jetson jet pack...

 

[simonb65]

Add points to your sketch and dimension them, then add a spline through the points.

 

[simonb65]

Example ...



You can then directly control the spline by just by changing the point dimensions as the spline nodes will constrained to the points. It is a pity that these points aren't generated when you create a spline, so as you say, you can dimension them!

 

[Willis123]

Thanks Simon. Your drawing is similar to mine. I'll dimension the points.

 

[Nick952]

Simon, I might be missing something here (quite probably) but if you draw a spline using the Spline Tool, you can create as many control points as necessary, by LMB Clicking at each point you need one, during the drawing process. Additional Reference Points can also be added (from within the Spline Tool drop down menu) later if required.
All the original and additional points can be dragged or dimensioned as required.
I use the ribbon so might be slightly different with the Menus.

 

[simonb65]

Simon, I might be missing something here (quite probably) but if you draw a spline using the Spline Tool, you can create as many control points as necessary, by LMB Clicking at each point you need one, during the drawing process. Additional Reference Points can also be added (from within the Spline Tool drop down menu) later if required.
All the original and additional points can be dragged or dimensioned as required.
I use the ribbon so might be slightly different with the Menus.

'Spline' gives you points which you can dimension and you can add additional reference points.
'Spline by Control Points' doesn't (only the end points can be dimensioned).
'Spline by Interpolation points' doesn't (only the end points can be dimensioned).

Sorry for the confusion, my example above used 'Spline by Interpolation points' and so the reference points for where I wanted the interpolation points have to be added and dimension first as they are not available for dimension afterwards, only manual positioning.

 

[Willis123]

I need to give myself a dope slap! I didn't realize there were other forms of the spline function. The "spline" function does give me the ability to directly dimension the reference points. Thanks Nick. Is there a good definition of how the three splines work? Seems like the "Spline by Interpolation" points is a spline where the points influence (by how much?) the line and the "Spline" points define the exact location of the line.

 

[Nick952]

If you type B-Spline into the search panel of the Alibre help menu and display the topics, more information is available, than if you just search for Spline.
That's about it I think.