Cutting a curved slot into a cylinder

[Anonymous]

I am trying to replicate this piece:

But I'm unsure how best to define the paths making the cuts.

I've tried Curve On Face in a 3D sketch, but wasn't able to constrain it tangent to the straight vertical portions at the start and end of each slot.

Lofts don't remain tangent to the outside face, and the resulting slot does not have a consistent width.

My best attempt sweeps a solid and results in a nice uniform width, but the path as I've defined it leaves sharp corners where the extrude cuts and coil segments meet.

How would you model these features?

Inventor 2020

Thanks

[Anonymous]

An emboss wrapped to the face gives much better control over the flow of the curves, but the cut tapers and does not have uniform width.

[jhackney1972 · Accepted solution]

The process you want to use is a Surface Sweep.  Take a look at the screencast.  I have included an Inventor 2019 file of the part, I hope you can open it to further explore the process

[SBix26]

Here's a solution using solid sweep in Inventor 2020.

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Sam B
Inventor Pro 2020.1 | Windows 7 SP1
LinkedIn

[Anonymous]

I'm able to sweep the cutting tool along straight lines as you have, but I would prefer a smoother transition between segments. If I replace the middle straight line with a spline that's tangent to the start and end lines, the sweep no longer works and does not produce a meaningful result.

In my experience splines are often responsible for features failing, so I also tried it with two tangent arcs in the middle instead. Selecting this path in the sweep command crashes Inventor.

Any further suggestions to get the solid sweep to cooperate?

[SBix26 · Accepted solution]

I was able to add curves to the path of the longer sweep, but the shorter one is just too abrupt. 

I think you will want to retain a straight section so that your slope doesn't get too steep.  The "all curves" path looks smoother, but it also makes the movement of the follower change directions more drastically.

Attached is my latest version (2020 format).

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Sam B
Inventor Pro 2020.1 | Windows 7 SP1
LinkedIn

[Anonymous]

I have tried to sweep through path and guide surface as above but I just can't get it to work

Can anyone help and tell me what I'm doing wrong?

I constantly get the error 'Could not build this sweep'

[Anonymous]

I have managed to fix it somewhat by increasing the radius of the corners which allows me to produce a 15mm slot however the milling cutter needs to stay perpendicular to the centre of the tube

See attached image A would be our milling cutter and the tube would rotate around the B Axis. I am getting this strange formation on part of the slot (see image Capture) which would be impossible for us to achieve in reality

[JDMather]

@Anonymous 

It would have been best to start a new thread (and link back to this one for reference).

And indicate what version of Inventor you are using.

General technique in this video.

https://youtu.be/Wekmai5MqFM

[johnsonshiue]

Hi Folks,

This is another case that Solid Sweep should help, where traditional Profile Sweep cannot generate the precise geometry. Solid Sweep has its own limitation. Some creativity in the toolbody and the path is required to make it work. Please take a look at the attached part (2020 or later). The resultant cut is quite different than the Profile Sweep.

Many thanks!

[Anonymous]

Thank you very much for taking the time to post this! Helped me too.