This is a model of the amtrak Superliner. It is 28.5 cm long and printable in one piece. To print it, make sure, that the buildvolume of your printer is big enough. I printed it on the creality cr10, with 30cm x 30cm buildplate.
To print the shell, do not fill the whole shell with support material. Just place three or four supports over the length of the shell. Make sure, that they are not connected to the walls, so it is easier to remove them after printing. I recommend to use white pla, and colour the car after printing. Also the windows in the shell can be printed without supports. It worked perfectly on my cr10. For the chassis, use only supports, that are connected to the printing bed.The Bogies can be printed without supports, while printing, for printing turn them upside down.Use part2 to mount the bogies to the chassis.The bogies can be equipped with normal h0 scale wheelsets of your trusted manufacturer.