How do I let my pieces be rendered by the server?

when a player with a slightly bad computer comes close to a moving piece, the piece becomes re-modernized by him, this ends up locking the moving piece for all players.
wanted to know how can i stop this?

You can use Part:SetNetworkOwner(nil). This will set the parts “Network Owner” (The Client that handles physics for that part) to the server

can you put this directly in a model?

For a model, just set the network owner to nil for only the RootPart of the model.

what would a rootpart be? a primary part? what if you don’t have one?

Yes, It would he the PrimaryPart. If you don’t have one, you need to set it to the part you are moving.

ok, i will set a primary part.
last question if the primary part is not with Weld on the other parts of the model so will the entire model be re-modernized?
(Sorry for bothering)