Hi Tim,

> I am having trouble with filleting edges, why will some sections not fillet?

It looks like the problem pieces are ones with thinner sort of slivery pieces, like the top of this one here:



Compressed and small thin areas (also things with approaching shared tangents like this) tend to be a difficult area of calculation.

It will probably be a while before stuff like this gets much better.

In this case, you can get fillets on most parts of the object if you select all edges except for the top 3:



It is also possible to construct the fillets in a much more "manual" way, by separating the parts into surfaces and then working on things at a more kind of low-level individual surface level, constructing fillet surfaces and trimming the other surfaces to create holes, and then joining together the final results. That tends to be pretty difficult and time consuming though.

Some other CAD programs like SolidWorks do have a more powerful fillet engine on them, if you need to do a lot of somewhat more complex fillets like this, you may need something like that.

- Michael