Torsion Spring Construction 1

[swhitmarsh]

Has anyone modeled a helical torsion spring? What are the steps?

It seems simple - just a helix with a small space between each coil, and a wire "tab" bent at each end parallel to the axis of the helix, with a minimum bend radius of 2X diameter of the wire. Our attempts have produced parts that look the part, but with errors.

The helix is no problem, just that bend at the end...

 

[eroy2]

If I remember correctly all I did was to create a line running away from the spring on the XY plane(assuming spring in the Z) drew a circle and swept it using the line as a guide. Then just moved the Coord system up to the top of the spring and repeated. once that was done used join command to create a join from the swept cylinder to the helix.

Hope it helps.

 

[swhitmarsh]

We got it. I wanted to finish this thread so that it may be of some use to someone else.

In short, we were put onto the “bridge” function in UG by the EDS tech support hotline, IR# 4823256.

In long, the spring we were trying to model is on page 315 Machinery’s Handbook, “Straight Offset” configuration. We reduced the number of turns in our helix by a fraction representative of the curve radius plus half the wire diameter. We created 2 planes, each offset from the ends of the helix by a distance equal to the bend radius plus half the wire diameter, both parallel to the XY plane. Then we created planes containing the Z-axis at an angle offset from the ends of the helix that would put our lines in the required position for locating the end tabs. We used “bridge” to create the 3D fillet between the helix and the line.

The rest is just a normal sweep. Worked great.