DUPLO Early Simple Machines missing parts

[Travis Cobbs]

I must say this is an interesting project, but I have none of these parts, so I have no idea of "common" dimensions, how they fit together, etc... I don't know if dimensions/photos alone would be enough.
Are the axles the same as normal Technic axles? Are the pinholes compatible with Technic pins?

I don't have the parts either, but I've seen them at LEGOLAND. To the best of my knowledge, the axles are the same as Technic axles, but twice as thick. The pinholes would be twice as big, also (obviously, to fit the axles).