Radius for inside of donut in affinity

Good Morning,

Can I get some direction from someone using AD ?

Using the donut hole - the setting for the inside radius in set at percentages. I tried the arrow to get a drop down and there were no selections there.

If I am using a donut hole to make a ring of a certain inside radius - I am talking about Jewerly ring sizes. Where would I set this up?

Looking at a ring size converter a us size 7 would have an inside circumference in inches of 2.09

Help appreciated always.

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I’ll tag @Xabbess here, she does quite a lot with Affinity Designer

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Thanks…I am sleepwalking a bit today …did not even think of that.


Hi. I saw the same thing…and even typing in 2.09 in place of the percentage didn’t work. I tried a workaround and don’t know how precise and accurate it might be…but it might work. I made a donut hole, then I made just a regular circle, no fill, just stroke. I sized the circle to 2.09 then slid it over the donut hole. Resized the inside radius of donut hole to match up with the circle. Then you could delete the circle


Do you think this might work for you? If there’s an easier and more direct way to do this, maybe someone else more knowledgeable will chime in.


That should work…

I will try it NOW…well maybe after a snack and trip to the bead store.

THank yoU!

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Where did you get your X and Y value at?
I tried changing them both to 2.09 for height and width but it kept changing/converting the other one to a different number.

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Use the gear creator tool. Set the tooth size and gap to zero and change the inner hole to the size you need.

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I didn’t do anything with the x and y. I only change the width and height.


Here’s the circle at the size of 2.09

and when resized…here’s the donut matching up with the circle

and what the numbers look like;


Of course, you would have to adjust the outer part of the donut to the thickness/width you want, and I’m not sure how to do that. I’m going to try @techniak’s idea with the cog and I’ll get back to you.

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I tried this idea, and it still gives the hole radius only as a percentage, not in inches. Thanks for the suggestion, though. Any other thoughts?

In thinking further on this, if you’re actually going to cut a ring, I wouldn’t even use the donut shape. I’d just use two circles, the inner circle sized to your 2.09, then the outer circle creating your ring as thick as you will want it…then, choosing both rings at the same time, use the boolean op to combine, as I did here. This is all one thing, now.


Using the circle tool the measurements do not stay the same =2.09 . When you set one number to 2.09 the other converts to a different number. It did not look round to me after that.

Two days of frustration —and I am the kind of person that sits in the chair until I figure it out…and I couldn’t yesterday and have to leave here to get the twins car seats put back in my truck. They get to spend the night with meemaw tomorrow.

My poor glowforge has been on for three hours and didn’t even get to print anything…

Be back…

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There’s a little icon next to the W and H numbers that looks like a chain. Click that to unlock the proportions, and THEN adjust the size you want in each. With it locked, changing one number will cause the other number to automatically change to match.


Thanks! One problem solved.

I hit that but I really didn’t see what it was doing…lol

Got it now !!

We shall see!

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Well, you are so smart! I never even saw that little icon, so sure couldn’t have helped out with that. I just tried it myself. Another learning moment for me. Thanks!

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Just thought I would let you know that with your help I cut a ring - It would fit a gorilla finger.
Numbers are not my friends- I am so fortunate to have people for that.

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No worries…numbers have NEVER been my friends, either. When young, many ask why they need to take any of the math disciplines…saying they’re never going to need most of it when they get older. Enter me; I have never used so much math in so many years as I have since learning to design for the Glowforge…but I’m not hatin’ it! Glad you had a success…even a gorilla-sized success.

Just food for thought.

What if you sized your outer dimension, then used the percentage value to get the inner value. For example: O.D. 2.5 inch then made the inner ring 83.6% (Affinity requires round numbers, so 83% or a close 84%… (2.09 is 83.6% of 2.5)

However, you need to rethink the math here. 2.09 is the circumference, which is .665 of an inch (diameter). So scaling down to the right outer dimension will lead to a less gorilla sized ring.

1 in. O.D. with a .665% I.D. will give you approximate size. Conversely, a 1.5 in O.D. with a 44% (ID) will yield the correct I.D. (.665 inch)

Just looking at it from a different perspective…

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Even more food for thought. Make a circle with the correct diameter of the ID. Make another circle with the correct diameter of the OD. Align the two by centering. That creates a ring shape and it’s easier than messing with percentages. :slightly_smiling_face:

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I sure can appreciate your knowledge, but you’re talking to two people who are not all that keen with math…which is what brought on the problem in the first place. :wink: :smile: