Hi Del, sorry I'm not familiar with Monolith - this here is the MoI forum which is a totally different software program from Monolith.

Does Monolith have its own discussion forum? If so then you might want to post your question there.

If the only way to convert from .stl to .vol is by using Grasshopper, then you'll need to use Rhino to do that - Grasshopper is a Rhino plug-in and both Rhino and Grasshopper are also different software programs than MoI which is the one that this forum is about.

- Michael