topic Re: Any idea how to manually create wrap in Inventor Forum

Any idea how to manually create wrap

danijel.radenkovic — Fri, 12 Aug 2016 07:55:18 GMT

Hello users,

I would appreciate any help to create wrap of this sketch arcs-manually (cause wrap option is not working on the "complex" surfaces).

Here is an image which shows what option I have tried and as you can see curve is pretty much deformed. Vertical projection is not solution also. I would like to have a nice smoothed wrap of curve on the surface bellow.

Regards,

Danijel

Re: Any idea how to manually create wrap

Frank-Oosterwaal — Fri, 12 Aug 2016 10:40:31 GMT

Hi Danijel,

I'm having a little trouble to understand what the sketch really should look like.

If project to surface doesn't give the desired effect then maybe you could make it manually with "Curve on Face"?

You could project your current 2d sketch (Project along vector), convert it to construction and use that as a guide for your curve on face.

Hope it helps!

Re: Any idea how to manually create wrap

JDMather — Fri, 12 Aug 2016 11:05:45 GMT

The best spline has as few points as possible.

You have way too many points in Sketch1 (Should be able to do the same spline with fewer than 6 points).

What is your manufacturing tolerance for the part?

Re: Any idea how to manually create wrap

danijel.radenkovic — Fri, 12 Aug 2016 11:17:03 GMT

You could project your current 2d sketch (Project along vector), convert it to construction and use that as a guide for your curve on face.

So, I am getting a copy of the projected curve. Am I right? I don't need to redraw a projected line.

Re: Any idea how to manually create wrap

CCarreiras — Fri, 12 Aug 2016 11:28:45 GMT

Hi!

Maybe this will work for you.

Check the file.

Re: Any idea how to manually create wrap

danijel.radenkovic — Fri, 12 Aug 2016 11:44:56 GMT

@Anonymous wrote:
The best spline has as few points as possible.
You have way too many points in Sketch1 (Should be able to do the same spline with fewer than 6 points).
What is your manufacturing tolerance for the part?

There are just two connected arcs so we have 3 points or if we add 2 midpoints for better approximation, then we have 5 points.

Tolerance is still not defined but displacement of maybe 0.5mm or 1mm is not a problem if we have smoothed 3D curve.

Re: Any idea how to manually create wrap

danijel.radenkovic — Fri, 12 Aug 2016 11:49:13 GMT

Hi,

But this is nothing more than vertical projection of curve.

Re: Any idea how to manually create wrap

JDMather — Fri, 12 Aug 2016 11:50:37 GMT

@danijel.radenkovic wrote:

@Anonymous wrote:

The best spline has as few points as possible.

You have way too many points in Sketch1 (Should be able to do the same spline with fewer than 6 points).

What is your manufacturing tolerance for the part?

There are just two connected arcs so we have 3 points or if we add 2 midpoints for better approximation, then we have 5 points.

Tolerance is still not defined but displacement of maybe 0.5mm or 1mm is not a problem if we have smoothed 3D curve.

I am lost?

Are you referring to the Sketch1. The foundation of the part geometry?

Re: Any idea how to manually create wrap

Frank-Oosterwaal — Fri, 12 Aug 2016 11:54:55 GMT

Hi,

You don't need to project the 2D sketch, you can make the shape you need just with "Curve on face".

I was just saying you can project the 2D sketch and use it to snap some points of your "Curve on surface" to as a guide.

Not all point have to be on the projected curve.

Re: Any idea how to manually create wrap

danijel.radenkovic — Fri, 12 Aug 2016 12:10:48 GMT

@Anonymous wrote:
@danijel.radenkovic wrote:
@Anonymous wrote:
The best spline has as few points as possible.
You have way too many points in Sketch1 (Should be able to do the same spline with fewer than 6 points).
What is your manufacturing tolerance for the part?
There are just two connected arcs so we have 3 points or if we add 2 midpoints for better approximation, then we have 5 points.
Tolerance is still not defined but displacement of maybe 0.5mm or 1mm is not a problem if we have smoothed 3D curve.

I am lost?
Are you referring to the Sketch1. The foundation of the part geometry?

Sorry JD,

I thought on Sketch2. Yes you are right, this is a spline created by many points (about 500). Reason that I need wrapped curve is to use loft cut function.

We can also use profile created by arcs (please see attached), so maybe it is better for your idea.

Re: Any idea how to manually create wrap

Frank-Oosterwaal — Fri, 12 Aug 2016 12:23:57 GMT

What about creating points in a 2D sketch, project those on the surface and make a smooth curve on surface through those points?

Is this something you're after?

File attached.

Re: Any idea how to manually create wrap

danijel.radenkovic — Fri, 12 Aug 2016 12:53:07 GMT

Hi Frank,

This looks pretty good, similar to vertical projection (according to length of 3D curve).

Here is something interesting that we have got in Creo, and the best results is given by toroidal bend function. and as you can see while other 3D curves are too short or too long, curve created by toroidal bend looks pretty as "natural" wrap.

If someone can open, here is also attached .prt.

Re: Any idea how to manually create wrap

jamesfgill — Wed, 23 Nov 2016 13:51:16 GMT

Hi Danijel,

I think you can make the 3D sketch geometry you need with this 3 step process:

Make an extruded surface.
Wrap the 2D sketch onto the extruded surface (i.e. 3D Sketch -> Project to Surface -> Wrap to surface).
Project the wrapped sketch to closest point (i.e. 3D Sketch -> Project to Surface -> Project to closest point).

For step 1 I made an extruded surface using the revolve profile:

Here is the result of step 2. The green curve was made by wrap and is on the extruded surface:

Here is the result of the final step. The red curve was made by normal projection and is on the revolved surface.

I used the measure tool to get the lengths of the curves. Note that the original 2D sketch contains 2 curves.

2D sketch: [curve 1] = 80.607 mm [curve 2] = 26.53 mm

Wrapped sketch: [curve 1] = 80.604 mm [curve 2] = 26.526 mm

Normal projected sketch: [curve 1] = 80.454 mm [curve 2] = 26.152 mm

The lengths of the 2D sketch curves and wrapped sketch are almost exactly the same, as expected. The computation of the wrap and the curve length both involve an integral, the tiny difference can be attributed to the approximation involved in the numerical integral computation.

The lengths of the 2d sketch curves and the final normal projected sketch curves are a little different. I hope that the difference is acceptable for your application. Note that the revolved surface is non-developable, so it is impossible to wrap the 2D sketch onto it without some stretch or compression.

I've attached the ipt I used. Let me know if you have trouble opening it, I might have used an internal Inventor build that is incompatible with your one.

Best regards,

James

Re: Any idea how to manually create wrap

danijel.radenkovic — Fri, 25 Nov 2016 09:01:06 GMT

Hi James,

I have checked solution that you provided and I realize that for now it is the only solution which is acceptable. The difference between 2D curve and Final 3D Curve is 0.378mm. Still, this is big difference but we are getting just bigger difference using any other way. We would like to appeal on Inventor developer Team to investigate the problem and we believe that some future options will provide better result and give us smaller difference between 2D curve and wrapped curve.

Thank you very much for the solution that you provided!

Danijel

Re: Any idea how to manually create wrap

Steven_Gao — Tue, 29 Nov 2016 08:42:10 GMT

Hi Danijel,

I followed James' method and did an additional step - before do the curve projections, I used the Move Bodies command to move the extruded surface with 0.83mm in Y direction. And now, the new projected curves have the approximately equal total distance(80.738+26.400=107.138mm .vs. 107.137mm) with the original 2D sketch curves. The method is just for your reference, not the best solution:). Please refer to the attached part for details.

Re: Any idea how to manually create wrap

danijel.radenkovic — Tue, 29 Nov 2016 16:45:54 GMT

Hi Steven,

Your solution is clever but keep in mind that I have many similar surfaces, so every time I have to adjust right value of movement of the surface.

That doesn't have a sense.

My friends have tested the same example in NX and Creo and send me results. I have also did in Inventor by the steps that James provided. Special thanks to James!

Using toroidal bend in Creo.