4th Axis Machining Geometry
4th Axis Machining Geometry
(OP)
Hello all,
I am trying to model a rather complicated part exactly as it should be produced. Imagine an hour glass shaped cylinder that is machined via 4th axis with a sine wave. I can easily make this cut on a surface, but the new surfaces formed are what trouble me. I have tried surface lofts, but I lose the control of the geometry that I need. Basically, what command options do I have to make these new surfaces accurately (accounting for the geometry of the cutting tool)? If I could do a swept cut that somehow stayed perpendicular to my rotational axis, that would be great; but I don't know how to make this happen.
Thanks!
Siress
I am trying to model a rather complicated part exactly as it should be produced. Imagine an hour glass shaped cylinder that is machined via 4th axis with a sine wave. I can easily make this cut on a surface, but the new surfaces formed are what trouble me. I have tried surface lofts, but I lose the control of the geometry that I need. Basically, what command options do I have to make these new surfaces accurately (accounting for the geometry of the cutting tool)? If I could do a swept cut that somehow stayed perpendicular to my rotational axis, that would be great; but I don't know how to make this happen.
Thanks!
Siress






RE: 4th Axis Machining Geometry
RE: 4th Axis Machining Geometry
Good day.
RE: 4th Axis Machining Geometry
Try dropping in on this NX thread: http://www.eng-tips.com/viewthread.cfm?qid=326303
If you want some of the sample files converted to step or parasolid let me know.
Ray S
NX 7.0.1.7
www.appliedprecisionproducts.com
RE: 4th Axis Machining Geometry
- - -Updraft
RE: 4th Axis Machining Geometry
Why do not you post an image and maybe with math definition so that we can better help you?
Best regards,
Alex
RE: 4th Axis Machining Geometry
Updraft, that's very cool, but I'm using SW2011.
Jassco, I may need to do that soon.
RE: 4th Axis Machining Geometry
Chris
SolidWorks 11
ctopher's home
SolidWorks Legion
RE: 4th Axis Machining Geometry
If that doesn't work perhaps this (older) technique will give you some ideas.
http://home.pct.edu/~jmather/content/DSG322/SolidW...
RE: 4th Axis Machining Geometry
RE: 4th Axis Machining Geometry
RE: 4th Axis Machining Geometry
There are many instances where swept-solid type (or complicated techniques to replicate this geometry) is the only way to create the digital geometry. This problem posted by the OP sounds like one of these cases. Similar problems have come up on the various MCAD forums over the years.
RE: 4th Axis Machining Geometry
Mncad, I've tried solid sweep cuts before, but it has never resolved a feature for me. I tried it again, following the included help file directions to the letter with defaults applied, and posted the error here. I then tried the method I actually want of keeping the tool body normal to the axis, and solidworks sat busy for 10min before I stopped it. [Note that I frequently model knurling in my parts, and that only takes a few seconds on my machine; it's not a slouch. And please reserve your judgements for applying knurling, it's because of reasons. :)] Perhaps you could direct me to a good example of someone doing what I'm attempting?
Regarding the attached, the part is a revolved spline. The cutting tool path is a 3D spline on the surface of the part (this provides me the actual geometry that I am concerned with detailing, instead of a wrap). The tool body is a simple revolved rectangle, not merged with the part, tangent to the tool path with the rotational axis of the tool body lying on the tool path.
Thank you all for your help!
RE: 4th Axis Machining Geometry
It appears that you do not have control over orientation of your cutter.
Best regards,
Alex
RE: 4th Axis Machining Geometry
It worked great for a helix, which was mildly exciting.
RE: 4th Axis Machining Geometry
You could do this without sweeping a solid. Draw the path like you did, then make a ruled surface (normal to the solid surface), and then thicken the ruled surface. I've had good luck and sound, workable toolpaths with this technique.
With the swept solid (or "simulated toolpath"), the side surfaces of the cut are determined by the orientation of the tool, and the tool is not necessarily held normal to the cut surface.
Also, it seems a bit of a stretch to force the cut to be made by a single pass of a tool of exact size. Sloppy. With that kind of inaccuracy built into the process, taking the effort to be overly precise is pointless.
RE: 4th Axis Machining Geometry
That actually worked on a simple cylinder, now that I knew how to do it. Thanks, TheTick!
Directions in case this comes up in a google search:
Once you have a tool path, create a line indicating the cutting tool's rotational axis that is incident to the tool path. Go to Surface-Sweep and select the tool axis as the profile and the tool path as the path, under options keep the orientation as Follow Path and change the Path Alignment Type to Direction Vector, then select a surface with an axis of symmetry the same as your part.
However, the same method applied to a wavy surface yielded the attached; which isn't close at all.
RE: 4th Axis Machining Geometry
RE: 4th Axis Machining Geometry
Note use of "spline on surface" in 3D sketch. There might be better ways, but I like this way.
RE: 4th Axis Machining Geometry
I'm getting a future version error, as I'm using SW2011. I still appreciate the effort.
RE: 4th Axis Machining Geometry
I took a look at the model you created. How do you know that the ruled surface created based on the 3D sketch (on surface spline) is normal to the cylinderical surface?
Best regards,
Alex
RE: 4th Axis Machining Geometry
RE: 4th Axis Machining Geometry
Thanks for the quick reply! My point is that the ruled surface has not knowledge of the cylinderical surface. When you created the ruled surface, you did not pick the surface. You only pick the 3D sketch.
Best regards,
Alex
RE: 4th Axis Machining Geometry
RE: 4th Axis Machining Geometry
Would someone be so kind as to open the file and save it as SW2011 compatible so that I may view it?
RE: 4th Axis Machining Geometry
Cheers,
Anna Wood
SW2011 SP5, Windows 7 x64
http://www.renderbay.com
http://www.solidmuse.com
http://www.phxswug.com