# Thread: Hole Patterns on Circumference

1. ## Hole Patterns on Circumference

I'm trying to produce 3 rows of 10 off Ø8mm holes on each row around a circumference of a solid model. Two rows being inline whilst the middle row being 1/2 way between the other 2.
Does anyone know which is the best way to achieve this?

Firstly I drew the pattern on a plane then wrapped it around the circumference but was then unable to 'Extrude Cut' the holes through, whilst trying to pick up on the sketched circles (holes)

Secondly instead of sketching the circles I created points, which I hoped I could then select the 'Extrude Cut' to locate on each point.
However, I was unable to Wrap the points around a circumference.

Any ideas anyone?

2. First make a single circle then an extruded cut. Next turn on Temporary Axis and use that for your linear pattern (see first screenshot).

Next use a circular pattern and use the the Temporary Axis for the axis of the pattern. For the angle change it from 360 to whatever you need and pick 3 for the quantity and this will split the outer two (see second screenshot).

Note: You could use multiple circles on the first sketch, but if they are spaced evenly it's cleaner to make a single circle and linear pattern it.

3. I use the hole wizard to place the first hole in each row directly on the circumference of the cylinder, then circular pattern it. Is this something like what you're after?
Chuck

4. First make a plane tangent to the edge, make a line on the plane you made then pick a (3d) sketch ,then draw a point then hole wizard. pick a holeor c'bore place it at the point you just draw that becomes your first feature then circular pattern pick the exe 90 eaqally spaced 3 instances.
dont know if that makes sense.

5. Originally Posted by leepez
Two rows being inline whilst the middle row being 1/2 way between the other 2.
Any above process will do but you'll need one extra pattern for getting middle row holes out of line.

Also, if the circle for the cylinder is centered on the origin you can use existing planes to draw hole circles & use end conditions: From-->offset-->value (cylinder radius minus hole depth) without needing to create tangent plane on circumference.

If you use hole wizard, AFAIK you can make the hole without the need of tangent plane. Just use dimension tool to position the hole from different directions, press tab to switch between directions.

6. Thanks for all your help Guy's got it all figured out now

7. Just goes to show there is more than one way to skin a cat.