Body Taper, NX 3

[jackley]

I recently found the body taper operation and would like some insight, if anyone has it.

Anyone really use this feature? I have a somewhat complicated bracket with a parting line that is defined using associative curves/arcs. Then using subdivide face.

I am not certain this is the best way to do a parting line.

But with regular taper (from edges and faces), my draft results are not in the proper location.

Any feedback with a proper technique with drafting and setting up a parting line, along with using taper or body taper?

Thank you.

Justin Ackley
Designer

 

[Xwheelguy]

Justin,

Have you looked in the documentation?

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.

 

[jackley]

Yea, I have looked it over. But I am confused on the 'Define Parting' option. Datum or surface, but with a simple taper it's no problem.

But if you have some complex parting line that walks up and down a part, how can you just use one datum or surface?

Justin Ackley
Designer

 

[cowski]

"Proper technique" really depends on the result you are after. Do you want to taper from the parting line so the part gets thinner out to the free edge or keep the edges where they are and add material as you get to the parting line? Subdivide and taper is good for the former (removing material) and body taper is good for the latter (adding material).

Here are a few tapering tips:
1) Taper face/taper from edge will generally fail if the taper would require a new face to be created, use split line taper in this case.
2) If any edges of the tapered face are to be blended, it is best to apply the blends after the taper(s).
3) When applying a taper with the 'from edge' option keep in mind that the 'true draft' option is "not required to meet the conditions specified by the taper Angle". This can be important in cases where a minimum draft angle is required (eg texture on parts).

 

[Xwheelguy]

Just a quick trial with a block, I created a very wavy freeform surface to simulate the walking you described. None of the 4 edges of the surface were the same in any way. The surface's edges were laying exactly on the block's faces, not completely passing through the block. This failed, I'm assuming due to a non-manifold condition.

Once I extended the edges of the parting surface so they all were outside of the block (larger than the block's cross section), then NX would create the draft on both sides of the parting surface.

Without seeing your part, it's hard to give any further suggestions on getting the surface you'll need. You'll just have to get your parting line curves projected onto the bracket's faces, then create a surface from those curves and finally Enlarge the surface or use Trim and Extend to get the surface edges outside of the bracket.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.

 

[hudson888]

As far as we could tell by experimentation the body taper feature will work quite well. It will use a plane or surface to create the split line about which it will apply a taper on either side. In doing so it seems that the only possible result is to maintain the sizes of the top and bottom making the body larger in the middle as taper is added either side of the split line.

In the simplest example of a 100mm cube tapered about a datum plate that is half way up, the top remained 100mm square, as did the bottom. The body taper added the split line and using 2 degrees of taper made the size of the body 103.492 square st the middle.

You can even use a sewn and complex surface as the split line and apply the edge matching option so that the edges match in the middle. In that case the sizes of the top and bottom are maintained while the draft angles are varied slightly to make the edges match along the split line.

It is really quite a clever tool with some really smart programming behind it. However most of the time I want to hold the size at the split line and slightly reduce the top and bottom to apply taper, so I have to use other methods that are more laborious to get the desired result. One method is to subdivide all the affected faces and apply tapers from the edges.

Hope this helps

Regards

Hudson