How can I evenly space holes of different diameters?

[dmvolz]

I am modeling a drill index.  The holes are the same distance circumference to circumference but they are all different diameters.  For example a .063 hole is .1" from a .094" hole which is .1" from a .125 hole etc. Is there an easy/quick way to do this? If I could dimension a hole to another hole circumference to circumference I would be okay with that but I can only dimension center to center. I could do the math to get the distance I want but I'm looking for a better/easier/faster solution.

[evanp4509U4JZ]

2 ways I can think of are to:

Draw a line along the direction of the size progression.

Draw a line perpendicular to that line at the start location.

Offset the second line the space plus the drill diameter.

Offset the third line the space plus the next drill diameter.

So on and so on.

Then either:

Draw 2 tangent circles using the intersection of the lines to make an index with a tangent front.

Draw center diameter circles at the intersection to make an index centered on the platform.

[etfrench]

Here's how I would do it:

Note: The base line can also be a curve, spline, spiral, etc.

[chrisplyler · Accepted solution]

Use a line through all the circle centers.

Put points at the desired places.

Dimension between those points.

 

[etfrench]

That will work for straight base lines, but not curves or splines.

[chrisplyler]

Well, the method still works. Now, the distance between the points is no longer the minimum distance between the circles, of course, because the curve isn't taking the shortest route between centers. But the process still works.

And you could instead control that minimum distance. Just need a line between the circles that is coincident to both centers. An extra step, but then you don't need to add the points, so it saves that step at least.

[etfrench]

Ah, yes, the additional line makes it work.

[dmvolz]

This was the best solution offered but still involved too many steps so instead of adding points I drew a construction circle of the the same diameter as the distance I needed and made it tangent to the first hole. Next hole tangentbto that. Copy & Repeat. This didn’t work so well going the other direction from a centered circle so in that case the points probably would have been better.

Thank you all!

[chrisplyler]

But tangent circles could result in this:

You would still have to do something to make sure they keep the minimum distance BETWEEN the holes. In which case you would have to draw the lines/points as I have done, and constrain the circles to those lines, which means you've added steps.

[etfrench]

If you had followed my screencast, you would have seen the circle used for spacing must be concentric with the circle for the hole. 

[chrisplyler]

@dmvolz  said he made tangent circles of the same diameter as the distance he needed between his holes. I was just pointing out that such a setup, all by itself, will not necessarily insure that the minimum distance is maintained.

[chrisplyler]

@etfrench  oops I thought you had relied to me.

[etfrench]

[lnonnato]

Dear all,

I think there was a little bit too much fuss over a simple problem.

IMHO, the simplest way to this would be to draw the reference line you want the circles on, be it a straight line or a curve, fix it and draw your circles with their centers coincident to the reference line, without caring with the distance between them.

If the reference line is a straight one, draw construction circles between each consecutive pair of circles with diameter equal to the desired distance , their centers also coincident to the reference line. Finally, apply a tangent constraint between consecutive pairs circle/construction circle. That's all.

If the reference line is not straight, before drawing construction circles you should draw reference lines between each consecutive pair of circles. Then, proceed as previously described (note that the centers of the construction circles should be coincident to these last reference lines).

The text for these instructions is rather convoluted, but the process is simple, as seen in the drawing:

Cheers,

Luiz

[etfrench]

Perhaps you should watch the screencast

[dmvolz]

This is what I did. But the real problem is that you can’t specify the distance between two circles in fusion 360, only the distance between the centers of two circles. Would have been much simpler to do that.

[tomjulier]

Isn't that what right-click "Pick Circle/Arc Tangent" does when adding a dimension or have I misunderstood what you're trying to do?

[chrisplyler]

Ooooh I didn't even know about that. That ought to solve this thread for sure. Fun!

[etfrench]

Ding. Ding. Ding. We have a winner  

Who knows what lurks on those sub menus

[dmvolz]

That’s exactly what I was trying to do. Thank you!