How to Constrain a Fillet to a Circle?

[Anonymous]

Howdy Gurus,

Suppose you have the following geometry:

Starting Geometry

And you want to create a fillet between two lines to the point where it is coincident to the circle. How do you do that?

How to Constrain Fillet to Circle

Thanks

John

[TrippyLighting]

@Anonymous AHA!

Now with all the added tangency constraints I see what you are trying to achieve.

I'd still argue that you would save A LOT of time by only sketching one quarter of this. To late for that now, you've done the work already. But worth looking at for the next project ...

[HughesTooling]

It looks like the 8 tangent constraints around the centre hole are red, is there an error showing? 

Mark

[Anonymous]

Yes, but I took care of it already. It turns out that whenever I change the dimension, it gets annoyed at the constraints and I have to go remake them. I think what happens is that it subtly pushes the (computed) arcs out of alignment to the point that they would be (should be) colinear constraints instead-- I made a big change in the diameter of the center circle and saw them get way out of position and when I went to investigate that was the obvious issue-- they were far enough out of alignment that there could no longer be a "legal" tangential relationship between the circles.

I like what I'm doing, which is working to learn how Fusion 360 works doing this and that. I have real parts to make, but I'm using them as excuses to experiment with different Fusion 360 features at the same time.

[Anonymous]

I definitely thank you for your careful and thoughtful assistance. While I did not use your method on this particular part, you definitely did show me a new way to approach the design process. I'm still pretty new at all this, though hopefully improving, and I have a lot to learn still. I have some little bit of experience with other (older) CAD programs and am having to *un-learn* stuff in order to get used to doing things the Fusion 360 way. I like the results, and I agree that the process is better-- what I know so far-- but I still have to go through the actual process to learn my lessons and internalize the methods. One thing that would help me would be having some written documentation for using Fusion 360 that I could pull out and refer to when I get stuck, and/or for tips and pointers. The videos and screencasts are okay, but they often go faster than I can follow or skip around thinking I should know things that I don't know-- and so sometimes end up being more frustrating than helpful. Though I'm certainly not saying that about all of them-- and particularly the one in this thread was really good. Very clear and easy to understand. But they're not all like that, so I end up having to search / watch / be confused / search some more / watch some more / etc. and it interferes with my learning process. If there are written docs anywhere, I would love to know where.

[TheCADWhisperer]

---

@Anonymous wrote:

SUCCESS!!! I did it. Your method was perfect!  

---

My definition of this is  - You are doing wayyyyyyyyyyyy too much work, but have a nice house of cards.

In general -

do not repeat dimensions

pattern features rather than sketch elements.