topic Re: How to make pattern of concentric circles? in Inventor Forum

How to make pattern of concentric circles?

Anonymous — Thu, 07 Mar 2019 11:43:21 GMT

I need to create a very large number of datum points on a disk, where each datum points lies at the intersection of a concentric circle and a radial "spoke" coming from the center of the disk.

I can make the "spokes" very easily by just creating a Circular Pattern of one line running from the center to the perimeter of the disk.

However, I do not know how to create all the concentric circles. Could anyone explain how to make a large number of evenly spaced concentric circles? Thank you ahead for your help.

Re: How to make pattern of concentric circles?

JDMather — Thu, 07 Mar 2019 11:56:42 GMT

Can you explain your end result Design Intent?

Can you post picture of something similar or a link to an image of something very similar?

Re: How to make pattern of concentric circles?

Sergio.D.Suárez — Thu, 07 Mar 2019 11:58:08 GMT

Hi, Could you attach a picture to better understand what you want?

Re: How to make pattern of concentric circles?

Udo_Huebner — Thu, 07 Mar 2019 12:10:21 GMT

If you need a lot of concentric circles with constant offset, you'll need a macro to quickly create those circles.
This can not be done with the sketch pattern functionality.

Re: How to make pattern of concentric circles?

Anonymous — Thu, 07 Mar 2019 13:54:57 GMT

I need to place hundreds of datum points at the intersections of a large number of concentric circles and radial lines. It's actually for making an optical disk not unlike an encoder. So at each intersection I'll be placing either a cutout or a solid block to encode digital information.

Here is a rough sketch that might make it a little more clear. The actual design will be laser cut and have a much larger number of circles and lines than shown in the sketch. Thank you guys for your help.

Re: How to make pattern of concentric circles?

Sergio.D.Suárez — Thu, 07 Mar 2019 14:09:32 GMT

Notice if it is possible to reframe circular patterns of operations, if it is possible to create a hole and a linear pattern, and then a circular pattern of this result, if it is not possible, check if there is symmetry, that is if you can cut the disk in 90 ° for example, and at the end of giving a circular matrix of 4 in 360gr, I would try not to model the whole set of holes in a sketch, I would prefer to work with patterns of operations.
Keep in mind that you can count on reference sketch pattern, for the part of the radial line (if the holes that cut the successive circumferences in radial line are not at the same distance between them).
Keep in mind that in many situations at first glance circular patterns are not displayed because there may be more than one overlapping and concentric pattern

Re: How to make pattern of concentric circles?

SBix26 — Thu, 07 Mar 2019 15:32:53 GMT

If I'm understanding correctly, you wish to place points (workpoints?) in a radial pattern. Do the concentric circles have any function other than to define the intersection points? Why not skip the circles and just make a linear pattern of points in a radial direction, then circular pattern that pattern (see below)?

Sam B
Inventor Pro 2019.3 | Windows 7 SP1
LinkedIn

Re: How to make pattern of concentric circles?

johnsonshiue — Thu, 07 Mar 2019 22:21:34 GMT

Hi! If the concentric circles are only for intersection to create the points, Sam's posting is the solution. If you do need to crate the circles for other purposes, you will need to create it one-by-one or use Offset command repeatedly to create multiple circles.

Many thanks!

Re: How to make pattern of concentric circles?

Anonymous — Fri, 08 Mar 2019 10:48:17 GMT

Thanks for the great ideas guys. I guess I should have thought of that. If anyone is interested, what I am actually trying to do is map the attached 2 dimensional array to a portion of the surface of the disk. Actually, to "wrap" it into a "washer" or "2D donut" shape, like represented by the shaded region of the sketch shown below.

Any thoughts on how to least-tediously do that? I don't suppose Inventor might offer some way of using an array of ones and zeros and some logic to draw a pattern? I have the array also in mathematical matrix (as opposed to graphical) form. Could I possibly employ some kind of logical condition where if an element of the array is a 0 then draw a circle (cutout) and if it is a 1 then do not draw anything?