CompuServe Thread

#Spiral Spring

5 messages in this thread
#21658From: IAN DAGGERNov 23, 1991 6:38 PM
We are trying to design a special purpose spring fro a client. We are attempting to do that we AME and having problems trying to mdel the shape. Does anyone have a sping routine ? is anyone doing any work in API or is it just shipped as a hang over from AutoSOLID and for show ? regards, Ian Dagger Sydney Australia.
#21676From: Dieter Schlaepfer [AdeskNov 23, 1991 11:06 PM
Ian, At this time, AME cannot create swept solids through a parametric path, even with API. This means that you can only roughly approximate the spring. You could do this by using the 3dpoly command, feeding it calculated points. You could create a circle at each vertex normal to the next polyline segment, extrude it along the segment and perhaps union it with adjacent extrusions. The bonus routine spring.lsp (I think that's what it's called) may be of use. Depending on how you will be using the model, perhaps the envelope of the spring would be sufficient: a cylinder, cone, or swept conic section. If you only plan to use the model for illustration or presentation purposes, you may want to create a wireframe representation of the spring and then use project.lsp to project the desired view onto a plane where you can then "fatten" it to the correct wire gauge. I hope one of these ideas will prove helpful. Dieter
#21740From: IAN DAGGERNov 24, 1991 1:55 PM
Dear Dieter, Thanks, I was expecting the answer that yoyu have given me. We need to do more than visualization. We were hoping to create springs under different conditions to get moments of Inertia, centroid etc…etc But thanks anyway. Is there any API products being developed ? Ina…
#21805From: Dieter Schlaepfer [AdeskNov 24, 1991 11:25 PM
Ian, If you need the mass properties of the spring under varying conditions, you might still be able to approximate it with AME close enough for your specifications. Of course the best approach would be to sweep a circle along a path but AME will need to support NURBs before we can offer that capability. I personally am not familiar with any API products currently available although I expect a number of developers are working on applications. You might want to contact the following companies for information: Swanson Analysis Systems, Inc P.O. Box 65 Houston, PA 15342-0065 Engineering Technology Associates, Inc. 1100 E. Mandoline, Suite B Madison Heights, MI 48071 Lapcad Engineering 1568 Diablo Point Court Chula Vista, CA 92011 Structural Research & Analysis Corp. 1661 Lincoln Boulevard #201 Santa Monica, CA 90404 Dieter
#21899From: Theo ArmourNov 25, 1991 1:59 PM
Last year I worked on several parametric 3D spiral routines – which I call "Spiralitis". I gave up because I did not know enough about spring and screw manufacturing and could not access such expertise. Cany you send any drawings of the springs you have in mind? I especially want to know what the typical beginnings and ends of springs (how they are cut or formed). I want to know if a sectional cut through a spring is circular or elliptical. And do you have any illustration as to the geometry of a spring that is in the process of being squeezed or stretched. Or is there a textbook about springs? Currently my routines are surface oriented – but I could look at AME possibilities. I had a lot of fun with variable radius springs, springs along splined 3Dplines, multi-thread springs that spiraled along the spiral, variable profile springs and lots of other good stuff.