I have molds for the handle and the teeth, but I hand make the blade lengths each time. When I made the first one I didn't know how to make molds for hollow castings and the weight of the entire chainsword in solid resin would have been close to 20 lbs!
Also, hand making the blades isn't actually very hard and I can customize the details each time (I'll have a picture next week of a totally different design finally!)
A chainaxe would also be pretty interesting to see, if you're wanting to do something a little further from things you've already made. Oh, I just thought of an idea I think would look really cool on a chainaxe. If the axe head's casing was shaped like an open-mouthed demonic silhouette. And I think it would go well with the vicious roar I think of when I picture a chainaxe being used.
A chainaxe would be excellent! I've also always had a soft spot in my heart for chaos plasma pistols, the old designs with lot of extra pipes and tubes. Maybe I should just make both and make some berserker armor and go cosplay as Kharn the Betrayer!