I've recently discovered Grind: what a beautiful game ! The rules are pretty clear and the official faq helps a lot but there is one thing I'm not sure about:
may a Steamjack end his movement near the Grinder, then pick it up and place it in other adjancent square (=push action) or does he need to move at least once with the grinder to push it and change its position ?
I think the answer is he needs to move at least once with it as the rules says that:
During its advance, a steamjack equipped with a control arm can push the Grinder.
So if you don't Advance, you can't push the grinder. And if you stop your advance near the grinder, you can't pick it up as it won't be during the steamjack's advance.
The rules also says that to push the Grinder you have to:
a/ Declare the Push and remove the Grinder from the field
b/ End the Jack's movement
c/ Place the Grinder back on the field
If the Steamjack ends his movement near the Grinder and then pick it up, he would firstly do b/, than a/, than c/. So that's incorrect.