Ramping a coil/helix

[sjthielbar]

I'm using Inventor 2012, and I'm trying to model a coil/helix. I've run into a new coil which after two revolutions with a tight pitch (.0005" over the wire diameter which is .0185") I need to make the next 3 revolutions ramping from a .025" pitch to a .060" pitch.

Any ideas? I'm thinking that it won't be possible using the coiling feature alone since there are no options to accomodate this.

[Cadmanto · Accepted solution]

I think it is possible, but you are going to have to orientate your planes such that when the one coild stops (flush with a vertical plane) the other one picks up with the other pitch.

Here is an example of what I was talking about.

What I did was create the first coil to your first specification, then the second was 1.5 turns at a pitch of .025 and the third was another 1.5 turns at .060 pitch.  I created a step file so you can at least have a model of it.  Because I have 2014 and you can't open the actual model file.

If this solved your issue please mark this posting "Accept as Solution".

Or if you like something that was said and it was helpful, Kudos are appreciated. Thanks!!!! 

     

[JDMather · Accepted solution]

3D sketch wrap displacement curve around cylinder.  (in later versions there are additional options, like equation curves)