Breaking down the workdesk_door with a custom joint entity

[Frontcannon]

I'm currently working on a puzzle which requires the player to pry open the door of the normal workdesk with a custom hammer entity which has been modified in order to behave like Frictional's crowbar_joint entity (only thing different is a different Min angle).

Problem
Once the hammer is in place, I can't move it far enough to make it look realistic. I can move it a bit, as much as the workdesk door allows (which is too little), but that was it. How can I force the door to open more when the hammer is used? Right now the hammer seems to be too weak, the door seems to block it even when it isn't locked.

I've tried modifying the door's body which worked, but it looked stupid (hammer just moves through door as if it wasn't there). I then tried to use the hinge so the door could only be opened the necessary bit for the hammer to complete the prying motion, but the hammer seems to be too weak / the door still blocks it.

Screenshot
Be patient, Imgur seems to be a bit slow right now.