topic Re: Wrap a body around a cylinder in Fusion Design, Validate & Document Forum

Wrap a body around a cylinder

Anonymous — Wed, 30 Mar 2016 03:58:46 GMT

How can I wrap body "B" around the outside of body "A"? I am attempting to create the profile in the drawing below the screen capture.

Thank you in advance.

Jason

Re: Wrap a body around a cylinder

michallach81 — Wed, 30 Mar 2016 05:05:32 GMT

Hi Jason, you need to show us more drawings of a part you like to recreate. First thing I can tell is, that if you would wrap body B around body A, in a section view straight line would be a curve.
Your attached section views, shows straight lines which mean you should rather cut cylinder with extrusion.

Re: Wrap a body around a cylinder

Anonymous — Thu, 31 Mar 2016 00:22:07 GMT

@michallach81 wrote:
Hi Jason, you need to show us more drawings of a part you like to recreate. First thing I can tell is, that if you would wrap body B around body A, in a section view straight line would be a curve.
Your attached section views, shows straight lines which mean you should rather cut cylinder with extrusion.

Michallach81,

Thank you for your reply. I am attaching two more drawings, this is all I have. I am trying to wrap this profile around the cylinder, then cut it out of the cylinder.

Re: Wrap a body around a cylinder

TrippyLighting — Thu, 31 Mar 2016 01:24:32 GMT

If these two drawings are to represent the same part then one of them is wrong.

If the cylider is created by rolling a

I suspect that these drawings were done in 2D CAD and that the person creating the draiwng did mot take thte time to draw the finished cylinders correctly.

Either way, you cannot just wrap a straight body around a cylinder in Fusion 360 like this. If you want that cut (gap) represented correctly you'l have to model a cylindrical/spiral object that can be cut out of that cylinder.

Re: Wrap a body around a cylinder

TrippyLighting — Thu, 31 Mar 2016 01:25:16 GMT

If these two drawings are to represent the same part then one of them is wrong.

If the cylinder is created by rolling a

I suspect that these drawings were done in 2D CAD and that the person creating the draiwng did mot take thte time to draw the finished cylinders correctly.

Re: Wrap a body around a cylinder

Anonymous — Thu, 31 Mar 2016 02:01:03 GMT

It is unfortunate that a plane cannot be "wrapped" around a tube / cylinder like a piece of paper. It would be MUCH easier than modeling the cuts on a round object. I will have to research how to make the measurements, and place the line points.

Thank you.

Re: Wrap a body around a cylinder

donsmac — Thu, 31 Mar 2016 02:44:55 GMT

This may help. I took your template drawing and opened it in photoshop in order to add the grid and centerline. This image was used as a decal wrapped around a cylinder. The grid was added to verify the decal image wasn't being distorted. I drew a sketch matching the centerline and projected it to the surface. Made a pipe object using that projected line, then split the surface of the cylinder. Did a Push/Pull to get the slot.

Re: Wrap a body around a cylinder

michallach81 — Thu, 31 Mar 2016 15:36:15 GMT

Hi Jason, drawings you've add are still not enough accurate. Not only the helix is shown as a straight line, we also missing some dimensions. As @TrippyLighting said, someone draw them probably in 2D, and I assume that he had some problems with drawing projection of a helix correctly. Conclusion is, that the section views are wrong.

How to create that part (if my assumptions are correct)?

@donsmac trick is nice but nothing like accurate, it may be usefull for CGI, concept modeling, organic shapes, but rather not for mechanical design (here's some of my advices on that: http://forums.autodesk.com/t5/post-your-tips-and-tutorials/making-smooth-surface-sketch-lines-for-3d-object/td-p/5870870 ). He uses a spline where we should use exact projection of a helix.
What's the difference. That gap we trying to get, serve as a slot for some pin, and that pin moves vertical. Helical shape asure that constant rotation of a cylinder will result in a constant move of a pin (linear function). Using a spline, will result in some accelerations and decelerations with constant rotation. Maybe it's not a big deal in this particular example, because it may fit tolerance we need, but in general you should try to find a way that is mathematically accurate.

In Fusion we don't have helix in sketches, so we will use Coil (with rectangular profile), and whole play is about figuring out heights an angles (revolutions), and some rotations (Move) afterwards.

Take a look

Ready part:

and flat outer surface (urolled in Rino 3D and imported back to Fusion):

Both files (cylinder and flat surface) I've attached down below. Cylinder file have a time line so you can investigate my workflow.

Re: Wrap a body around a cylinder

Anonymous — Thu, 31 Mar 2016 17:06:54 GMT

All,

My appologies, I uploaded the wrong image of the cam slot. No wonder everyone was telling me that it did not have enough information. Again so sorry for posting the wrong image.

Re: Wrap a body around a cylinder

michallach81 — Thu, 31 Mar 2016 17:18:21 GMT

I'm not sure but my model should fit rather fine ( Ok, I've lied, I confident that my model must fit, but I have no time to check it now). Try to play with my model, if you'll have some questions after that, don't hesitate to ask.

Re: Wrap a body around a cylinder

Anonymous — Thu, 31 Mar 2016 17:20:41 GMT

@michallach81 wrote:
I'm not sure but my model should fit rather fine ( Ok, I've lied, I confident that my model must fit, but I have no time to check it now). Try to play with my model, if you'll have some questions after that, don't hesitate to ask.

I am studying it now, thank you so very much for the assistance. I have only recently stated to use Fusion and am looking for the helical tools as I type this. 🙂

Re: Wrap a body around a cylinder

Anonymous — Fri, 01 Apr 2016 14:21:26 GMT

Thank you michallach81. I appreciate the time you took to point me in the correct direction. I think I finished it correctly. fingers crossed.

Re: Wrap a body around a cylinder

michallach81 — Fri, 01 Apr 2016 15:41:30 GMT

Looks solid.