Wrapped curve on cylinder: how to create desired rise angle?

[mralexandermiller]

Hello, everyone! I've got a question which is difficult for me mathematically as technically. There is a cylinder solid body and adjacent sketch with a line by 45 degree to the cylinder's XZ plane. I wrap this line onto cylinder surface, and if we create a plane parallel to the XZ plane through the most upper point of the projected curve and spline the cylinder end face, we obtain a new line crossing the cylinders circle section in some point. We can connect circle center and this point, so this radius creates and angle with the "main" radius in the XZ plane. Ufff, sorry for this sophisticated description, you can observe all of it on the part1.ipt. So, when I change the line's length on the Sketch2, I see how the angle descripted changes (as a driven dimension). I need this angle to be 30 degrees, and I can "guess" the line's length increasing and decreasing it until the angle be 30 degree. But if you know the way how to do it analytically in Inventor, please help me. In other words, how to make the driven dimension of the angle required not-driven, and the line's length be driven dimension vice versa. Thank you very much!

[JDMather · Accepted solution]

See Attached.

[mralexandermiller]

Thank you!

[SBix26 · Accepted solution]

Here's the exact same equation applied to your file.  I prefer to generate helical paths by the wrap technique as you did.

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Sam B
Inventor Pro 2021.1 | Windows 10 Home 2004
LinkedIn

[mralexandermiller]

Thank you, sir! It seems to be so easy and obvious after somebody shows you "how to"! From this question appears a new one. I know how to "engrave" a "furrow" in the barrel with some "cut body" using Sweep command with this "cut body" as a tool body and the resulted curve as a path. But after the solid sweep command how to move the "cut body" by this path to be aligned to the "far end" of this part like it was at the "near end" of the part before the movement (like in my file). Sorry for excessive disturbance, but I really did not find any helpful information. Thank you.

[JDMather]

What does the tool look like that will be used to cut that slot in the real world?

I would expect a cylindrical end mill rather than a box shape.

Are you attempting to reproduce a real world part?

If yes, any images of the real (or similar) part?

[mralexandermiller]

Sir, I just chose this form of "cutting" pin, because it could be more useful for me to examine the right angle (it should be 30 degrees in the most far point of the "path"). And of course it isn't a CAM tool. I just want make a simple mechanism when a sliding pin in a parallel manner (with one side moving in a straight slot of the fixed part, which I didn't show in my files and the other side in the curved slot in the twisting barrel) and makes the "barrel" part turn until the latter reaches 30 degree. So it is...

[johnsonshiue]

Hi! Another option is to create Helical Curve in 3D Sketch. Starting from 2019, the Helical Curve and be variable-pitch and variable-radius.

Many thanks!

[mralexandermiller]

Hi, there! I found how to answer my own question, if someone interested of it, I show the answer here, because the solution is not so obvious as it could seem. So, just use the Rectangular Pattern with path and Curve Length instead of Spacing which is default, then in advanced settings (>>) Compute -> Identical and Orientation -> Direction 1 (it is your path chosen). Here I attach the file with this exercise.

Thank you 🙂