As long as you don't need detail, such as rivets, an FDM printer can print good, durable handrails or fencing in PLA plastic. In the above photo are N scale handrails that are 0.4mm thick, which is the same as a standard size FDM printer nozzle. Just make sure the bed is optimally leveled and that the handrails aren't thinner than your nozzle size. Print flat on the bed and you can print whatever basic handrails you need. Layer height is up to your own preference so experiment. For small scales, design the handrails square instead of round. Such handrails only require beginner skills to make, and could be made in a simple program like Tinkercad or AI assisted with something like CADAM. While not as crisp and sturdy as something like etched metal, they are easy, cheap, and quick.
