When I was interested in that custom player animations thing, I wanted to apply the same concept to weapons. Tried Shaper, but just like what you're having it didn't export any animations.
I did some more research on dts importers and I found a program called Ultimate Unwrap 3d. It's $50 to get, but it's dts importer is absolutely flawless and it can export to almost any format. I bought it myself and it works really nicely.