Change radial spacing of hole pattern extrusion

[Anonymous]

Hi all,

I have a fairly complicated hole pattern (hexagons with a number of parametric relationships) that I want to extrude through a flat circular plate while "contracting" the pattern radially, so that the hole centers end up being closer together while the integrity of the pattern and hole diameter is preserved.  

I have attached a screenshot of a much simpler mock up part I have been trying to find a viable method to achieve this on.  I've been experimenting with using a sweep with a guide rail to force the pattern to contract through the extrusion, but it also decreases the size of the holes and fails because it says the path doesn't intersect the profile, and the rail doesn't intersect the profile (even though they both intersect a hole center).

Any ideas?

Thanks very much!

[SBix26]

More detail needed:

- Is it a radial pattern?

- Are the hexagonal holes oriented perpendicular to the hole axis (i.e. is the intersection of a hole with the top surface a skewed hexagon or a true hexagon)?

Seems to me that you could create one hole at the correct angle, either by sweep or extrude, and then pattern it?  Or is that too simple?

Best would be for us to avoid guessing and have the actual file to work with.

---

Sam B
Inventor Pro 2019.1.1 | Windows 7 SP1
LinkedIn

[SBix26]

I've attached a part (2018) for you to look at.  This has a hexagon extruded through the disc at an angle (see below) and then circular patterned.

Is this what you are trying to do?

Sam B
Inventor Pro 2019.1.1 | Windows 7 SP1
LinkedIn

[johnsonshiue]

Hi! The warning should be benign. In your case, there are 5 circular profiles and only one intersects the path and one intersects the rail. The warning is legitimate. Maybe, when all 5 profiles are selected in this case, the resultant body is bad. You could try creating one sweep feature based on one circular profile. Then pattern the feature. Does it work?

If you cannot figure out, please attach the part here. Forum experts can help take a look and propose good workflows to achieve desirable result.

Many thanks!

[Anonymous]

Hi Sam and Johnson,

Thanks very much for your input!

To clarify I have attached 2 parts: the first part has a sketch with the wide hole pattern that I want to be extruded into it with the spacing between holes decreasing and holes staying the same diameter (this is necessary because balls will roll in the channels), and the second part has the tighter hole pattern that I want the transition to.

Unfortunately, the warnings on the sweep don't let me proceed and generate the feature, FYI. 

Thanks very much and I hope that helps clarify!

Peter

[johnsonshiue]

Hi! There should be multiple ways to do this. I have found an interesting solution for the Wide part. Please take a look. I don't get what you want to do with the Thin part though. I guess the same technique can be used there too.

Many thanks!

[SBix26]

Is this anything like you have in mind?  Note that in order for balls to roll through these channels the holes have to maintain a circular cross section, making their intersection with the top and bottom surfaces elliptical; quite severely so at the outer extremes.  This effect would be reduced if the thickness of the part increased.

---

Sam B
Inventor Pro 2019.1.1 | Windows 7 SP1
LinkedIn

[SBix26]

Here's a better way to accomplish the same result as posted yesterday.

---

Sam B
Inventor Pro 2019.1.1 | Windows 7 SP1
LinkedIn