Hi Andrei,

> Could you more detail say what is surface offset distances?

It's a surface that is a constant distance away from the base one, basically moved by the given distance along each surface normal, here's an example of a base surface and it's offset surface of a particular distance:



- Michael

If I understand right, moi make base fillet surface than offset it and make trim?

Hi Andrei,

> If I understand right, moi make base fillet surface than offset it and make trim?

No, the offset happens on the already existing surfaces on either side of the edge that's being targeted.

Like this:



Putting in a fillet of radius = 4 :



That means offsets like this:




The "rails" for chamfers are done in this exact same way as for fillets, it's just that instead of a rounded piece put in, a straight line is put in instead. When you use 2 chamfer distances it means each of those lines shown above uses its own separate offset distance rather than them both using the same one.

- Michael

Thank you very much for you explonation, now I understan it is offset from surface to radius point. And when I enter distance I enter that radius.

So for example with 2 chamfer distances of 4 and 3 it would be like this:





- Michael

Thank you Michael you are the best! :)

Hi Andrei,

> Thank you very much for you explonation, now I understan it is offset from surface
> to radius point. And when I enter distance I enter that radius.

Yup, that's correct. For an entire fillet surface that "radius point" is a centerline path curve, and it's formed by calculating the intersection between the 2 offset surfaces.

Then chamfers are done in the exact same way, which is kind of unfortunate in some aspects because there would probably be easier to understand ways to control it. But it's standard for CAD programs to deal with chamfers in the same way as with fillets, just with a straight surface put in rather than an arc put in for the cross section shape.

- Michael

My mistake was that I thought that I enter this distances:

Seems for a Chamfer you right!

> My mistake was that I thought that I enter this distances:

It would make sense to do it that way if it was restricted to only ever work on planar surfaces.

When each of those surfaces are curved surfaces rather than planar ones, then a measurement like you show there becomes difficult to deal with.

- Michael