I am trying to build a robot which is having Bevel Gears connecting two links. I want to calculate DH parameters, but i am stuck with this bevel gear as when the joint rotates both angle and displacement are being changed.
When you think about the mechanism the gears are offset, but the joint itself has an axis. You should use that axis which may not be overlapping/coincident with the link attached to the bevel gear.
I found a few tutorials that you may find useful: