variable pitch helix

[warmblood]

I need to construct a variable pitch helix on a diameter 200mm circle(drawn on the top plane, on the origin), 4 revolutions, clockwise, starting at 270 degrees (on the front plane). The pitch is initially 100mm (rev 0) and must be gradually changed to meet a point 350mm vertically straight under the starting point of the helix (also on the front plane).
By simply tweaking the pitch in the table at rev 4 to a number of values, I have found this value to be 75.

How can I work this value out each time instead of tweeking the last pitch in order to reach my 350mm specified height?

This can save me a lot of time since I need to create a number of variable pitch helixes that needs to go through specified points.

Please help

 

[bvanhiel]

I haven't needed to do this for a long time (SW2001), so there might be better answers. Use equations to define the mathmatical relationships. It will take some figuring the first time, but once you've got the first one done you should be able to do the others quickly and without iteration.

-b

 

[CorBlimeyLimey]

You can create a DT & populate it with the helix dimensions, then use formulae in the DT to control them.


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[dezignstuff]

rumor has it sw07 can create helices that vary in pitch and diameter

 

[CorBlimeyLimey]

SW06 already does that ... or am I misinterpreting?

http://www.mooload.com/new/file.php?file=files/270606/1151366797/Variable+Helix.SLDPRT

Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[neilc78]

You can get advanced helix creation abilities by buying Geometry works. See the SW partners on the SW website.