Good sir,
By now you have read the concerns that the other contributors have for your safety and I will assume that you have weighed the risk on personal injury and have deemed that it is an "acceptable risk". I will not echo the concern of others for I feel that my concern for your safety will also not be heeded...
So let me put the message in another perspective: Bypassing the security door and tightening screws during the operation of the device has a greater risk of causing mechanical failure in the event that either you or your tools (oil can, screwdriver or loose screw) fall into the working mechanism and become embedded into the machine. This would create a much greater MTTR than performing proper maintenance and would carry a much higher cost of repair.
Also, my business involves critical care equipment to EMS and ambulance services around the world, and I have a very close relationship with medical personal in many countries. As such, I have seen the results of scenes where maintenance crews have been seriously harmed by taking short cuts. Regardless of your concern for personal safety, I can tell you that the manufacturing process was shut down for a considerably longer period of time than if routine maintenance was performed properly in the first place.