Help Modeling Torsion Spring
Help Modeling Torsion Spring
(OP)
I need help modeling a special torsion spring. I want the legs of the torsion spring to be parallel to each other. My current model depicts uses 3 curves (2 straight lines, and a helix) combined into a composite curve, and then I swept the whole thing. This produces a torsion spring but the legs are not parallel to each other. By parallel I mean if you are looking down at the coils, and the legs are in either direction, they are not parallel.
If this is not clear I would be happy to e-mail my model to someone to help clarify the problem.
Thanks.
If this is not clear I would be happy to e-mail my model to someone to help clarify the problem.
Thanks.






RE: Help Modeling Torsion Spring
Then, I select each of the ends of the new sweep, convert the entities on the face (circular, probably) and extrude the length of straight spring I need. They should be parallel.
One thing to note with this method is that instead of creating a new plane "normal" to the end of the helical coil, I use one of the standard planes and make sure my helix intersects it. I place my cross-section on that plane and pierce it to the helical path. This allows my starting and ending faces to be parallel with one of my three primary planes. If you don't do this, but add a plane normal to the curve, your results won't necessarily be parallel.
Jeff Mowry
DesignHaus Industrial Design
http://www.designhaus-i-d.com
RE: Help Modeling Torsion Spring
Scott Baugh, CSWP

3DVision Technologies
http://www.3dvisiontech.com
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When in doubt, always check the help
RE: Help Modeling Torsion Spring
Jeff Mowry
DesignHaus Industrial Design
http://www.designhaus-i-d.com
RE: Help Modeling Torsion Spring
RE: Help Modeling Torsion Spring
There are a number of things that could benefit from some form of "variational" geometry that could be manually or even automatically configured form, say mates, in an assembly. Years ago, the old CV CADDS system had some abilities in variational properties of inserted parts (sfigures, nfigures, xfigures).
Any thoughts out there?
RE: Help Modeling Torsion Spring
I completely agree. Most of the springs that I have made use a Design Table to make all of the configurations necessary. Doc – Free Length – Compressed – Compressed to length A – B – C. It doesn’t seem to matter how many compression lengths a spring may already have, the next time I use it I have to add another length or two.
In my opinion, it would be much better to provide (for a compression spring) a special dimension with a Min/Max relationship that would allow the spring to flex. Mating would be much simpler.
RE: Help Modeling Torsion Spring
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........(case sensitive) URL is http://rschwarz.tripod.com/CAD/TorsionSpring--2003-03-10.zip
A few notes about this model.
* The model is oriented "in machine position" w.r.t. it's parent assembly.
* There are quite a few construction features before I lay down any solids.
*pay close attention to equations and linked values
1.) I begin by sketching the diameters, and then I made a sketch of the legs in the closed position.
2.) The next sketch moves the "lid leg" centerline to a position where there would be an even number of turns in the helix.
3.) The "toggle" sketch is used to control leg positions algebraically using equations. I have had poor results using configuration-specific equations. As-saved, the position and toggle sketches are visible. Viewed from the left view, you can see the lengths of the toggles change when you change configs, "switching" the various elements of the control equations. When a toggle's value is "1", then the equation causes the associated term to cancel out by multiplying by zero. "2"="on", "1"="off".
4.) Helix length and number of coils are controlled by equations which tie these properties to sketched positions.
5.) I use a copy of the helix to make the swept body. I find that using the actual helix causes the endpoints of that helix to be unavailable for future operations.
6. I use a patterned copy of an extruded surface to generate the moving leg's centerline. This is more robust than using patterned sketch entities. I also add a perpendicular surface at the base to use for sketching.
This may be more involved than you care to get. It does suit my needs well.
Best regards,
TheTick
RE: Help Modeling Torsion Spring
RE: Help Modeling Torsion Spring
remember, its CAPS SENSITIVE
RE: Help Modeling Torsion Spring