i have a rhino file(.3dm) that i want to use in inkscape , what type of file should i save it as so i can use it. i've tried .stl.obj and .ai but none of them work

I would use dxf or svg.

OBJ works nicely - but I guess you have to put it into the Inkscape package. You can load it then from Extensions->Render->3D->3D Polyhedron=Object: Load from file

mine is just lines so that i can cut it with my laser cutter, cant seem to get any file i change it to to load

Feel free to share an example .3dm file for testing.

i think this is the one 

i had to extrude it to make it possible to make an .stl which needs to be solid, the lines are underneath, if you get rid of the solids you can see them , i made the file in Matrix , a jewellery plug in for rhino

I'd save from Rhino as dxf with cubic splines.

Converted 3dm to FBX online and loaded into my beloved 3d app. Deleted everything except top polygons and unwrapped UVs in flat projection to export as PDF. Opened in Inkscape; killed stroke, added fill color and after Path->Union this is what I got. Not perfect in certain areas - I know:

In Rhino, I'd just select the curves and save as a dxf with cubic splines.

which version of rhino are you using ,i don't see cubic splines in my one (v4) but what you have is exactly what i need ,can you upload it so i can copy it?

What happens when you export dxf from Rhino?

this is what i get , it looks ok till you look close , every line is separate and the circles are made up of hundreds of lines

I'm not actually using Rhino... I'm using MoI3D (written by the guy that wrote Rhino).

Here's the dxf and the svg.

Note that there is one feature that should be moved from layer one to layer two. 

thank you