making a helical half sphere ? 2

[FXjohn]

I'm trying to make a design out of helical wrapped wire that makes a cylinder and the ends in a half sphere. I;m not sure how to apply the law curve function to do that. NX 7.5

see attached picture and UG file

thanks

 

[FXjohn]

here is the UG file

 

[stephlouv]

A quick idea.
Do a revolve, in sheet mode, to create your half sphere.
Then project the spiral on this surface upon the Z axis.

 

[FXjohn]

hey that is a good idea, thank you

 

[FrankSwinks]

Here is an alternative using a law curve.

Frank Swinkels

 

[NXherbie]

Hi Frank,

I wonder what happens to the Tube when you assign the Turns expression a value of 11.8 or 12?

NXHerbie
NX7.5.3.3

 

[FXjohn]

thanks, FrankSwinks. good work

 

[cowski]

I wonder what happens to the Tube when you assign the Turns expression a value of 11.8 or 12?

Edit the tube parameters and use the "multiple segments" output option for this case.

www.nxjournaling.com

 

[FrankSwinks]

Hi NXHerbie,

To add to the last turn change the PitchAngle expression to be 90/(floor(turns)+1). Then you can set turns to say 10.5 etc. There will still be a limit to get a valid tube in the last turn.

Frank Swinkels

 

[mmauldin]

Stephlouv's approach results in an uniform radial pitch when viewed from the top of the dome.

Frank's approach results in a uniform spacing along the face of the sphere.

Attached is a third approach approach that results in a constant pitch along the z axis and controls the helix radius with a set of law curves.