Mike J Wilson - Consider the date!

I went to Mike's site to show a colleague some animations and found the Autodesk site. Could this have something to with the date and time? (a.m. on the 1st of
April)
Anyway, why I was there was....
I am trying to animate a coil spring expanding and collapsing. I realise this is possible using an incrementing equation to govern the helix height, but how do you assign an equation (or a dimension for that matter) to the helix height? The helix property manager spin box only seems to accept numbers.
Any help would be greatly appreciated.
Gavin C.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I use equations with spring helices all the time.
All you need to do is double-click the helix in the feature manager tree and the dimensions appear like any other feature.
I find it helpful to first rename all of the spring dimensions so that I'm sure I have the right ones when I'm picking them for equations.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hmmm... Thanks for the reply.
I must be doing something fundamentally wrong. I'm creating a circle and then invoking the Insert/Curve/Helix-Spiral command. I then Sweep a circular sketch along this spiral to create the spring. I cannot for the life of me assign a height to the spiral using a dimension. Any idea where I'm going wrong?
GC

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Yep. I know what's wrong.
Helix is a funny creature that only likes to be used once and forgotten. Once you use it in a feature, the endpoints can't be referenced to make planes. Perhaps this time it has also decided not to be available for equations.
Roll back to before your helical sweep and create a temporary guide curve to replace the one in your sweep. Edit your sweep so it's not using the helix anymore, and then try to access the helix's parameters.
When I make spring coils, I copy the helix into a 3D sketch and use that in the sweep, due to the reasons mentioned above.
I have a torsion spring model you might want to see. It's available at <http://www.esoxrepublic.com/models/ . It's not an extension spring, but you can still see how to link spring parameters to equations.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.