mating a spring to a shaft

[LocusIndustries]

In an assembly, how do you mate a compression spring around a shaft using a concentric mate. The compression spring is made by extruding a helix using a circle as the shape to sweep. The spring does not have any surface to select in order to concentric mate to a cylindrical shaft. I tried showing the spring diameter sketch and mating this concentically to the shaft, but that does not work either.

 

[SnowCrash]

Make an axis for the spring and make it concentric to the surface of the shaft. The axis can be based on two planes that define the part. Then locate one of the spring planes parallel to one of the shaft planes. Finally, locate the plane of the spring circle sketch as required to the features of the shaft. Fixed!

Crashj 'boing boing' Johnson

 

[macPT]

Another idea:

Maybe you created the shaft and the spring with default planes centered along the longitudinal axis of these components(this is the way I would model them). The origin of each part should be coincident with these two planes.

Just select one longitudinal default plane of each component and make a coincident mate. Select the other longitudinal default plane of each component and make a coincident mate again.

The spring is now centered in the shaft. No need to create reference geometry.

Regards

 

[Mandrake22]

Snowcrash,
Thanks for your tip. I have been trying to mate a spring into a cylindrical pocket this morning. Even though I have been using temporary axes as mates, I didn't think to try it out here. I was faking the spring by making a very thin cylindrical cut into the ID of the first coil. That worked, but the axis mate is much better. By the way, I used the default temporary axis and didn't have to create a new one.

 

[Mandrake22]

In my previous post, I said that I didn't need to create an axis in the spring to mate with. This of course was proven incorrect after I deleted my cylindrical cut and the spring mates blew up! The temporary axis I was using was created by my cut, deleting the cut feature deletes this temp. axis as well. I quickly created the axis as SnowCrash suggests and all is well again.