Ive drawn a 3d model in autocad and imported it as a 3ds file to Blender. When applying materials I have found that some of my objects are all grouped together on the wrong layer. Can I split them up in Blender on to different layers? When I use the M button to move the object to another layer all the objects move and I really need to move them one at a time onto different layers. Can I do this on Blender or do I have to re-import it in the 3ds format?
You need to ungroup the objects first. Select the group, press CTRL+G, then select Remove From Group. After that, you can move individual objects to different layers.
They are not grouped, they are one object. In edit mode select the parts you want to separate (press L with the mouse above it) , press P. Now you can move them to another layer.