I love halo, grew up on it; modeled this as a gift for my girlfriend (and me)!
This is a model made in Maya LT. There is a Maya LT file for editing as well as FBX.
This model is to scale, my target height was 203.7cm. https://www.halowaypoint.com/en-us/universe/weapons/gravity-hammer
There are three ways to go about printing this:
Print the "GravityHammer_FULL.obj" - This is the whole thing, scale it to 10% for a nice desk piece.
Print the "GravityHammer_Top.obj" & "GravityHammer_Bottom.obj", and find a pipe that fits inside the carved out holes, then pop thoes puppies in! (Or, print at a smaller scale with the same idea) OR just print the "GravityHammer_InnerRod.obj".
Print all 26 split parts (GH_Top_01-21, GH_Bottom_01-05), find a tube, and have yourself a real gosh darn Grifball time! (ball not included)! note: inner rod should be LESS THAN 4.5 cm in diameter and 177.8cm in length. Please test fit!
I saw there were a lot of models online that were rips directly from the Halo 3 game files. Those files are awesome, but since they ripped a game engine model, they lost detail that would have been baked into the normal map.
There should be plenty of detail now in the base geometry. The only thing I did not put in the model are the rivets; my opinion is they can be carved in with a dremel or painted with a circle template to a better result.
Things to note are the model's edges; this model is comprised of polygons, so the curved faces are going to show some stepping. To counter that, the model has a ton of geometry, and has been combined.
Good luck and have fun!