How do I cut a specific curve shape across a cylinder?

[glencandle]

I need to cut a channel into the side of a cylinder, with specific start and finishing points.  And I need it to have a specific shape, so I need control over that as well.

I want the channel to run from point A to point B, which is at the top of the cylinder but only 45-degrees around the circumference.

The Coil tool does not have enough control to pull this off as you can see, but essentially that's what I'm trying to do.

What are other techniques for doing this? 

Ideally I'd like to sweep a profile along a curve with the exact shape I need, but I don't know how to sweep a curve along a three-dimensional face.

NOTE: 
I have tried a 3D sketch by projecting the top of the cylinder, snipping it down to match up with the points, then using a Coincident Constraint on the lower point. But this presents two issues: 1) the curve pushes away from the surface of the cylinder in the middle because the angle is no longer right, and I still don't have control over the shape of it after that.

Is there a way to create a curve with more control?

[davebYYPCU]

Build the Path with Surface > Create > Sweep.

Use a profile centre line, sweep to height at 45 degree twist angle.

Use a Pipe on the Path, or create the profile sketch.

Most trouble occurs when the Path is too short, and there is a remnant portion of the channel not finished off.  Delete Face (sometimes) or make the Path longer.

Cant open the file, (travelling).

Might help…..

[Warmingup1953]

Emboss? Your sketching seems to indicate 90 degrees of rotation?

[TheCADWhisperer]

@glencandle 

Can you explain how you will manufacture this geometry in the real world?

Can you explain the function of the geometry in the real world?

Simple sweep will not result in correct geometry.  Solid body Sweep is needed.

Emboss will not result in correct geometry, but there are two techniques that will (considering that Fusion does not have Sweep with solid body toolbody.

[glencandle]

Thanks Dave.  Can you elaborate on the first bit:

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Use a profile centre line, sweep to height at 45 degree twist angle.

Do I sketch a vertical line through the center of the cylinder?  What does "sweep to height at 45 degree twist angle" mean?  When I open the Sweep dialogue I see options for Profile/Path/Guide Rail, but nothing about height or twist angle.

Cheers.

[glencandle]

This will be a lid/body combo where the lid slides down onto the body with a 90-degree twist, and is meant to rest at the bottom, not lock.  (I was considering a 45-degree twist but I have decided 90 would be better.)

But the caveat is that I want the slide at the end to be more horizontal than vertical, which is why I want it to be a custom curve.

Cheers.

[jhackney1972]

I am not sure this is the curve you desire.  This is a simple 90 degree twist along the surface of the cylinder from your two points.  I do not know if your path needs to end perpendicular to the ends or not.  In the supplied model, the black line on the surface of the cylinder can be used to create a Plane Along a Path, to sketch any profile you need, or can be used by the Pipe command.

[Warmingup1953]

Can you sketch your desired curve onto a plane as a 2D Sketch?  Will you 3D print?

[glencandle]

Sure, this is more of less what I'm after. And this is for CNC aluminum.

Cheers.

[Warmingup1953]

I think Emboss should work fine in this case. Well it would in my version) Do you have access to axes greater than 3? (Not tomahawks btw!)

[davebYYPCU]

Not ignoring you, but no desktop till tomorrow night, so will sort it then, if needed.

[glencandle]

Thanks for the vote of confidence. I will be shopping this part out to 5-axis shops. I'm not familiar with using Emboss in F360. Is there a steep learning curve?

[jhackney1972]

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@glencandle wrote:

Is there a steep learning curve?

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Oh, I would say between a 3% to 5% grade.  Just create your sketch you want Embossed on a plane that if it were a sheet of paper, you would roll it around the cylinder, the chose the Emboss command and follow the prompts.

[glencandle]

Well that sounds too easy, I would prefer if it was more difficult 😉