Accurate method to wrap a sketch to a cylinder

Hi,
I think this has not been posted before, here is an accurate method to wrap a sketch onto a cylinder.
CleanShot 2022-03-22 at 00.35.36

Orthogonal projection of a plane onto a cylinder creates distorsion. One solution is obviously to slice the cylinder to reduce error. The following table gives an estimation of the maximum error of the projection for a given number of slices.

image
2 slices means projection of a plane on half the cylinder, which leads to infinite distorsion at the limit of the projection.
With 16 slices, worse case error is less than 2%, which is not noticeable.
With 64 slices, worse case error is about 0.1%.

The idea is to create a flatten version of the cylinder, project the sketch on the flatten version, extrude it if needed, and then wrap the cylinder to create the final shape in a systematic way, using mirror and align tools.
Itā€™s a five minutes process for 16 slices, as in the video, but it just requires 1 additional minute to go to 32 slices :grinning: and do not require any computation at all.

There is only one limitation: ensure there are no spline control point too close (less than 0.01mm) to any sliceā€™s edge or extrude may fail.

This method can be extended to project a sketch onto a cone :slightly_smiling_face:
Accurate method to wrap a sketch around a cone

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Excellent demonstration. Bravo!

Super helpful right now. Thank you.

Great work ā€˜aroundā€™ (pun intended) and exactly the way that Iā€™ve been doing it both here in Shapr3d and in SketchUp.

Hi Macher, welcome to this forum.

I think your boss should not say that as he would be mixing to separate topics.

If the question is ā€œdo we miss a wrapping or emboss functionā€, the answer is yes, no debate on that. The minute it will be available, we will all use it.

But at present, we donā€™t have wrap or emboss tool, leaving only two things we can do:

  • ask for it : it has been requested several time so Iā€™m 100% sure the Shapr3Dā€™s team is aware of this;
  • find the best solution to replace this CAD function with as little effort as possible for those who donā€™t have access to Solidworks, Fusion360, Inventor, Rhino, etc on their tablets, which was my two centsā€™ contribution.

So now Iā€™m afraid that you put your boss intro troubles :wink: as he will have to prove he is the boss :innocent:
Can he beat 1 minute with no visible distorsion, using only Shapr3D and a better method? Lets call it the One minute challenge ! :1st_place_medal:
CleanShot 2022-03-20 at 17.44.40

  • The first step of the method, you have to do it only once in a lifetime, as you can save the flatten shape and scale it to the desired diameter when you re-use it, as in the video;
  • The second step = the sketch, you have do do it anyhow, so it is not taken into account for the time.
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