Problems transforming a .3dm file into a .glb file

I have a R8 file of 210Mo that I want to transform into a .glb file while reducing the size so it can be used in"Framevr". I have tried using “save small” but when I do the transformation the file blows up to the original size. I used the “Draco” method but not with success. I did succeed in reducing the size but it would not open in Framvr. Help