Maybe a stupid question, I have made a mechanical rig and after tweaking lots of values it works well. If I delete the rig, the objects move around slightly and do not look correct, I know I should not delete it, but maybe in some case I do not want it for example exporting the model with no rig.
Is there a way of applying the rigs influence on the objects without loosing its functionality?
Wow I found it, I selected the rig in pose mode, all bones and apply as rest pose, then Apply- Assign custom property values as default. Now objects stay put when I delete the rig. 
Thanks anyway, maybe it will be useful to somebody else.