How can I "Wrap" a sketch around a curved surface for extrusion?

shane_evans075

I'm looking to project a sketch onto the side of a round object and I want it to wrap around the object so I can extrude it. Like this:http://help.solidworks.com/2012/English/SolidWorks/sldworks/HIDD_DVE_SURF_WRAPPING_SKETCH.htm?id=bc27a946a6044b5db933523bfd78ce83

I know there is a designated way to do it with Solidworks but I am trying to teach it to my students with Onshape and can only extrude directly from a workplane that is offset from the surface. This leads to a distorted hole or flat surface.

Thanks for the help in advance!

NeilCooke

Hi @shane_evans075  - currently there is no function in Onshape to wrap sketches onto non-planar surfaces. You can request functional enhancements through the feedback tool, top right.

NeilCooke

Hi @shane_evans075  - currently there is no function in Onshape to wrap sketches onto non-planar surfaces. You can request functional enhancements through the feedback tool, top right.

biscuitlad

Did you try extruding a surface from your sketch 'to next' or 'up to face' of the side of your round object?

Stephen_Lamarre

I hope you have figured this out by now, though for anyone that is still unsure how to accomplish this task; you need to first create a plane parallel and offset from the face you desire to extrude. Sketch the shape you wish to extrude on the new plane you have just created. Then extrude the sketch with two end points, from here you can calculate or drag the extrusion to remove the desired amount of material in both directions. Happy fabricating. 

benjamin_d_amour

Hi Stephen,

The only issue with your solution is the angular offset created by not translating the 2D sketch to an angular object.  As an example, If I create a drawing perpendicular to a tangent of the curved surface and sweep this into a cut, it will not create the same shape as a cut from a parallel-to-the-tangent sketch (unless you are sweeping 90, 180, or 360 degrees; in which case it is possible to achieve the same shape).

We are asking for a mapping feature, by which a complex shape can be sketched in 2D and mapped onto the 3D angular face and extruded along the perpendicular of the tangent; thereby preserving dimensions and angular relationships.  This is fairly complex bit of mathematics, as the sketch and extrude must be calculated for some small dx for the entire length/circumference. Albeit, a fun equation to code.  One example that I am currently working on is a telescoping cylinder lock channel.  I require the channel to maintain dimensional accuracy and have all cut faces be perpendicular to the tangent, which is incredibly difficult without sketch mapping.

Best,
Benjamin

Wolfram

Any new functionality related to this?

chris_bottino

Following up after Wolfram's unanswered last couple mo's ago... any new functionality?  Need to wrap text to cylinder.  Cannot create accurate M/F dies with extrusions (Add / Remove) on 2 to be mirrored cylinders.  I cannot create a "cylindrical" plane to extrude to, right?? (and maintain the correct angles). Please keep us in the loop.  Thanks

konstantin_shiriazdanov

@chris_bottino spicifically for text there exist a feature script https://forum.onshape.com/discussion/4223/new-curved-text-featurescript

john_mcclary

+1 to improvement request

I use wrap patterns to put holes and slots in the side of a sheet-metal plate wrapping around a helix for one of our main products.

Solidworks does O.K. at this, but I have to manually trig-out most of the hole locations, It would be nice if OS can come up with a cleaner solution, maybe give us a boundary sketch based off the selected surface's "flat pattern" that we can dimension / sketch to.

dave_cowden

@shane_evans075 I have created a feature script for this that works pretty well. You can put text onto a curved surface

You can read about it and find it here:
http://store.parametricparts.com/store/p10/CURVED-TEXT-1.0

Or you can open the Onshape FeatureScript directly here.
The only thing to be aware of is that your baseline should generally NOT be at the very bottom of your surface. In Onshape, some letters actually extend below the baseline, and you'll see that some letters ( like 'J') do not render if your baseline is the bottom of the surface.

Give it a try and let me know if it works for you!