Hi Leonard, yeah usually you need to get the pieces combined together into one single solid and then you fillet the edges of that solid.

Check out the sunburst and six-legged pod video tutorials here:
http://moi3d.com/1.0/docs/tutorials.htm

They go through the steps of building some separate pieces and then combining them together into a solid and filleting the edges.

Unfortunately you are going to have difficulty filleting this one here:



because the "seam edge" of the tube is so close to the edge you want to fillet - one of the major current limitations in MoI's filleting mechanism is that it will not make a fillet that crosses an edge like that, you can only go up to it and not over it.

So for example that edge will only be filletable up to 0.2 inches, not larger.

If you need to go larger than that, if you could post your original curves you used to make the frame I could probably help you with that by adjusting the circle's position to make the resulting seam edge be in a better place.

- Michael