After completing the DD35 design one final improvement was needed to make it an accurate model; the corridor through the middle.  Bachmann’s very first model of the DD40AX was the only one to have a corridor that you could see through.  This was because there was not much of a chassis inside to get in the way.  All of the subsequent models had the opening in the shell but the large chassis with their twin motors blocked off any possibility of seeing through.

As we have already been cutting bits out of the chassis we used for the DD35, Bob Norris came up with the idea of cutting out a bit more.  Using the printed body as a guide, he cut the chassis down as far as the running board and removed the material.  Then he added two small “jumpers” at the top of the gap.  These were glued in place to strengthen the chassis.

When the shell was replaced the effect was fantastic, the DD35 now has the proper corridor though the middle.

Instructions on how to do this with your printed model can be found here.