CAD Forum - tips, tricks, discussion and utilities for AutoCAD, Inventor, Revit and other Autodesk products []
Cesky English Deutsch
 Visitors: 2903 

CAD tip CAD tip # 9038:

Question CAD 
 %  platform  category 
Q - question

Double helix - twisted pair in Inventor

A - answer The Equation Curve function (parametric 3D sketch) can be used also to generate double helix (helix on helix), e.g. to make a model of a twisted-pair cable.

An example:

To model such assembly, just use the function "Equation Curve" (3D Sketch > Draw > Equation Curve) and then Sweep (3D Model > Create > Sweep) of a circular profile along this curve.

Fot the equation curve, use e.g. the following parameters:

x(t) = cos(1 rad*t*PI)*100+cos(1 rad*t*PI)*5*cos(10 rad*t*PI)
y(t) = 5*sin(10 rad*t*PI)+80*t
z(t) = sin(1 rad*t*PI)*100+sin(1 rad*t*PI)*5*cos(10 rad*t*PI)
tmin = 0 ul
tmax = 6 ul

In the equations, the value of "10 rad" represents the number of wire twists per each loop of the helix, "80" is the pitch (height) of a half-loop of the helix, "100" is the radius of the helix, "5" is the wire radius.

Using this 3D sketch and sweeping of a circular profile (2D sketch) perpendicular to the curve you can make one wire. The second wire (with different color) is only rotated and offset. The rotation angle is 180/"twists per loop" (here: 18) and the offset in the Z axis is "half-loop pitch"/"twists per loop" (here: 8).

Similarly you can create also other types of 3D models, e.g. cooling pipes, etc.

100% *  CAD 
17.1.2013    9506×  
applies to: Inventor 2013 ·

See also:
Tip 10708:Modeling compression injection screw for molding machine.
Tip 10138:Dimensioning a curve length or distance between two points on a curve.
Tip 9692:Unfoldable spiral-helix sheet metal in Inventor.
Tip 8832:Bent coil (helix) in Inventor.
Tip 6650:Break curve at all listed distances (stations).

Back   All CAD Tips All CAD tips&tricks

Have we helped you? If you want to support the CAD Forum web service, consider buying one of our CAD applications, or our custom software development offerings, or donating via PayPal (see above). You may also add a link to your web - like this "fan" link: CAD Forum - tips, utilities, blocks for Autodesk products
CAD:    OS:    Categ: 
Text:  FAQ glossary   

Increase your productivity with our set of BIM add-on functions for Autodesk Revit
CADstudio Revit Tools More info

Please use these tips at your own risk.
CAD Studio is not responsible for possible problems that may occur as a result of using any of these tips.